South of Spain: Mar Menor Lagoon
Ant-a Claws
-
In honor of Darwins' anniversary of On the Origin of Species.
New Papyrus: Darwin
it takes 20 000 genes to make a nematode and 25 000 to make a human
http://www.livescience.com/technology/technovelgy_eyes_041104.html
Charles Darwin recognized that the eye would be a real test of the theory of evolution. He suggested that it might be possible to evolve an eye from "imperfect and simple" forms:
"To suppose that the eye, with all its inimitable contrivances for adjusting the focus to different distances, for admitting different amounts of light, and for the correction of spherical and chromatic aberration, could have been formed by natural selection, seems, I freely confess, absurd in the highest possible degree.
"Yet reason tells me, that if numerous gradations from a perfect and complex eye to one very imperfect and simple, each grade being useful to its possessor, can be shown to exist; if further, the eye does vary ever so slightly, and the variations be inherited, which is certainly the case; and if variation or modification in the organ be ever useful to an animal under changing conditions of life, then the difficulty of believing that a perfect and complex eye could be formed by natural selection, though insuperable by our imagination, can hardly be considered real."
Scientists today believe that the eye could evolve from a single light-sensing cell. Scientists disagree over whether it evolved just once, or many times.
It turns out that Nature is both creative and generous with her gifts. Recent research has shown that the tiny marine worm Platynereis dumerilii has two types of light-sensing cells. The eyes of the worm have rhabdomeric photoreceptors, a compound lens formation that is seen almost exclusively in insect eyes. Rhabdomeric photoreceptors are covered in little finger-like protrusions. In its brain, however, it has a different kind of light-sensing cells - ciliary cells that are seen in vertebrate animals. Ciliary cells have hair-like cilia that extend outward and branch out like tiny umbrellas. Two different ways of sensing light in a single organism! images
http://scienceblogs.com/pharyngula/2006/09/rhabdomeric_and_ciliary_eyes.php
Researcher Joachim Wittbrodt of the European Molecular Biology Laboratory in Heidelberg, Germany speculates that the ciliary cells may regulate the worm's daily activity cycle, saying "We think they are related to circadian rhythms. We have found that there is a direct connection to the area used for locomotion... In the beginning we had a toolbox... what was in the brain in the worm ends up in our eye." If the animal had two copies of the genes needed to make one kind of photoreceptor, speculates Wittbrodt, then the extra set would have been free to evolve into the other photoreceptor. Different animals would subsequently evolve to use the two options in different ways.
-
Genome: Ramen noodle folding form (no knots) is fractal globule based on icosa-dodecahedron.
"perfect" genome code
empirical genome code
"perfect" periodic table
-
I have speculated earlier here and elsewhere, that the human thumb's missing bone and associated muscle evolutionarily moved to become the fused mandible (lower jaw) and tongue.
-
I posted this comment at a biology website (RDF), in response to why flies have 6 legs and most vertebrates have only 4 [clue - beetles have 4 wings/jaws, reptiles have 4 legs]:
bilateral pentadactyle digits (insect legs/"hands"/wings/"jaws")*
bilateral pentadactyle digits (invertebrate squid tentacles)*
bilateral pentadactyle digits (vertebrate fingers/toes)*
(larval bilateral) pentadactyle digits (starfish or sand dollar)*
icosahedral/pentameric (eg. virus) symmetry (12 oral/anal sets of five cilia)
*digits can be asexually replicated (due to incomplete meiosis?) or mutatively lost, body segments also, so bilateral millipedes simply have axial multiple copies of their earlier rear set, while bilateral vertebrates have axial duplicated the pelvis from the forelimb carriage or axial duplicated the rear limbs on a rear part of the primitive forelimb carriage which eventually moved caudally.
Flies have 6 legs, 2 wings, 2 wing knobs = 10 digits (no jaws just sharp tubes, larval jaws are forelimbs)
Spiders/crabs have 8 legs, 2 pedipalps ("jawclaws") = 10 digits (no wings)
Squid have 8 regular tentacles, 2 long "thumb" tentacles = 10 digits
Reptiles, fish, mammals (primitive) have 10 digits (forelimbs), 10 digits (rear limbs)
Evo-devo, human mandible/tongue associates with the missing thumb bone and muscle, while the maxillae associates with the four fingers (before mandibular separation, all five fingers).
Probably, due to the developmental order, a fly would be more likely born without wing knobs or wings than to be born without legs, since legs seem to be more ancient. One born without a leg pair probably also has other more severe genetic mutations, especially in internal segmental replication. While a reptile with 6 legs must oxygenate them with lungs, sufficient oxygenation is critical (dolphins lost their legs as oxygen conservation became more significant) while small insects' spiracles provide enough O2 for many legs, and wings help gain more O2. Perhaps.
-
There is an invertebrate (marine proto-crustacean?) which cannot eat unless it locomotes all limbs, its jaws can't chew unless its digits are moving. This would seem very primitive, since lobster claws and fish jaws operate independently from the legs or fins. Note that while larval caterpillars chew using their 4 forelegs/jaws, adult butterflies only suck nectar while still.
Caterpillars chew with forelimbs modified into jaws, during pupation these jaws reform into webbed wings, so butterflies can fly but can't chew. Grasshoppers do not pupate, they go through stages of enlargement and add wings at a certain instar stage (they can't eat at this stage). The adult grasshopper can both leap and fly. Humans have webbing between thumb and forefinger and between maxillae and mandible (cheeks), in flying insects the same genes form webbed wings associated with jaws; initially (ancestrally) this webbing assisted in filter feeding in early marine invertebrate, moving food particles closer to the mouth orifice.
The primitive invertebrate ancestor had an oral-GI-anal pore/tube with 5 mobile cilia, with variable degrees of rigidity (tentacle vs tendon/bone) and inter-digital webbing, depending on whether the food drifted by current (river) or was static and required cilia pulsation and attachment.
Interesting news confirms earlier speculations
link
Public release date: 20-Apr-2007
[ Print Article | E-mail Article | Close Window ]
Contact: Anna-Lynn Wegener
wegener@embl.de
49-622-138-7452
European Molecular Biology Laboratory
Researchers discover that the centralised nervous system of
vertebrates is much older than expected
The rise of the central nervous system (CNS) in animal evolution has
puzzled scientists for centuries. Vertebrates, insects and worms
evolved from the same ancestor, but their CNSs are different and were
thought to have evolved only after their lineages had split during
evolution. Researchers from the European Molecular Biology Laboratory
(EMBL) in Heidelberg now reveal that the vertebrate nervous system is
probably much older than expected. The study, which is published in
the current issue of Cell, suggests that the last common ancestor of
vertebrates, insects and worms already had a centralised nervous
system resembling that of vertebrates today.
Many animals have evolved complex nervous systems throughout the
course of evolution, but their architectures can differ substantially
between species. ...all these species descend from a common ancestor
called Urbilateria. If this ancestor already possessed a nervous
system, what it might have looked like and how it gave rise to the
diversity of nervous systems seen in animals today is what Detlev
Arendt and his group study at EMBL. To do so, they investigate the
nervous system of a marine annelid worm called Platynereis dumerilii.
"Platynereis can be considered a living fossil," says Arendt, "it
still lives in the same environment as the last common ancestors used
to and has preserved many ancestral features, including a prototype
invertebrate CNS. Comparing the molecular fingerpint of Platynereis
nerve cells with what is known about vertebrates revealed surprising
similarities.
"Our findings were overwhelming," says Alexandru Denes, who carried
out the research in Arendt's lab. "The molecular anatomy of the
developing CNS turned out to be virtually the same in vertebrates and
Platynereis. Corresponding regions give rise to neuron types with
similar molecular fingerprints and these neurons also go on to form
the same neural structures in annelid worm and vertebrate."...
The findings provide strong evidence for a theory that was first put
forward by zoologist Anton Dohrn in 1875. It states that vertebrate
and annelid CNS are of common descent and vertebrates have turned
themselves upside down throughout the course of evolution.
"This explains perfectly why we find the same centralised CNS on the
backside of vertebrates and the bellyside of Platynereis," Arendt
says. "How the inversion occurred and how other invertebrates have
modified the ancestral CNS throughout evolution are the next exciting
questions for evolutionary biologists."
http://chancenecessity.blogspot.com/2009/02/geoffroys-lobster-and-animal-common.html
-
urbilateria
A similar study involving Platynereis dumerlii comes to much the same conclusion. PZ Meyers has a explanation of this bit of research. This result, that humans are evolutionarily slow has been portrayed as a bit of a surprise, but is something that has been in the works for awhile. For example, as early as 1992 it was known that insulin genes in humans and apes evolved at a slower rate than in monkeys. The phenomena, called the “Hominid-rate-slowdown hypothesis”. was first suggested by Goodman in a 1961 paper entitled “The Role of Immunochemical Differences in the Phyletic Development of Human Behavior” (published in Human Biology) and led to papers being published on the subject up to the present (here and here for example).
http://www.hoxfulmonsters.com/2008/12/living-fossil-platynereis-dumerilii-unraveling-the-first-steps-of-eye-evolution
-
updated from earlier post (Vertebrates are inverted invertebrates).
To continue, with slight clarification, if interested:
See Neil Shubins slideshow, especially page 6 slide 5, to compare Hox gene positions in human and fruit fly.
http://tiktaalik.uchicago.edu/book-tools.html
My earlier explanation of primitive pentadactylity (5 digits) didn't well cover the duplication of reptile/mammal rear limbs from the forelimb carriage, this duplication is actually the same as the duplication of (beetle) 4 wings / 4 jaw mouthparts from the primitive frontal digits.
-
(I've briefed the text)
Dragonflies & damselflies (Odonates) can chew but they can't walk, their 6 legs are for perching and grabbing.
http://theatavism.blogspot.com/2009/11/sunday-spinelessness-damselflies.html
"You can tell a damselfly from a dragonfly thanks to the way they hold their wings - damselflies fold them up over their body when they land (butterfly-like) while dragonflies hold them open (moth-like)..." Interesting, butterflies or moths can walk a bit but can't chew, beetles & grasshoppers can walk and chew but their flight is not so well controlled.
wiki lacewings/netwings/antlions
The insect order Neuroptera, or net-winged insects, includes the lacewings, mantidflies, antlions, and their relatives. The adults of this order possess four membranous wings, with the forewings and hindwings about the same size, and with many veins. They have chewing mouthparts, and undergo complete metamorphosis. Neuropterans are soft-bodied insects with relatively few specialised features. They have large lateral compound eyes, and may or may not also have ocelli. Their mouthparts have strong mandibles suitable for chewing, and lack the various adaptations found in most other endopterygote insect groups.
They have four wings, which are usually similar in size and shape, have a generalised pattern of veins. Some Neuropterans have specialised sense organs in their wings, or have bristles or other structures to link their wings together during flight.[4]
The larvae are specialised predators, with elongated mandibles adapted for piercing and sucking. The larval body form varies between different families, depending on the nature of their prey. In general, however, they have three pairs of thoracic legs, each ending in two claws. The abdomen often has adhesive discs on the last two segments.[4] ...ant lions, which bury themselves completely out of sight and ambush prey from "pits" in the soil. Larvae of some Ithonidae are root feeders, and larvae of Sisyridae are aquatic, and feed on freshwater sponges. A few mantispids are parasites of spider egg sacs.
As in other holometabolic orders, there is a pupal stage, generally enclosed in some form of cocoon composed of silk and soil or other debris. The pupa eventually cuts its way out of the cocoon with its mandibles, and may even move about for a short while before undergoing the moult to the adult form.[4] Adults of many groups are also predatory, but some do not feed, or consume only nectar. They are delicate or cumbersome flyers, the spoon wings have rear wings like birds of paradise. Nemoptera
Nemoptera larvae
http://theatavism.blogspot.com/search/label/sci-blogs
It's a springtail (Collembola) - a member of a group of arthropods closely related to (but distinct from insects). They get their common name from a long forked organ, the furcula, that usually sits folded up under the abdomen. The earliest fossil hexapod, and one of the first terrestrial animals, Rhyniella praecursor, is a springtail...'Gomph's live in Antarctic mainland, springtails importantly make soil. Tail derived from crab/crayfish folded tail?
Orobophana pacifica: They are tiny, live on coral rubble on Cook Islands. Even though they live on land they aren't closely related to the "true" landsnails in the order Stylommatophora. To see the difference you need to look into their eyes. If you click on the image above to get a high resolution version you might just be able to see the eye - it's a black dot just underneath the tentacles ("feelers"). In true landsnails like the ones you find in you garden the eyes sit on the ommatophores, a second set of tentacles which are retractable.
bird feet, talons, webbing
Can you walk and talk and chew gum at the same time ?
The mechanics of being Human: a self-balancing, 28-jointed adaptor-based biped; an electro-chemical reduction plant, integral with segregated stowages of special energy extracts in storage batteries, for subsequent actuation of thousands of hydraulic and pneumatic pumps, with motors attached; 62,000 miles of capillaries.... R. Buckminster Fuller-
Bucky: Dictators never create their own opportunities.
A neat series of articles on human facial expressions (non-verbal communication), especially interesting after having read that human cheeks are merely muscular/fatty webbing connecting the mandible to maxilla like butterfly wings. Makes me wonder about the link of the smile to the crinkling of the eyelids or the tightening of the eyebrows, all these facial muscles which communicate internal feelings instantly which are usually masked by reflexive social gestures. They must have evolved in deep time, and gradually fine tuned in humans, a super-social species.
facing others
Human social traits: anonymous, cooperative, infants
Hrdy sociality hypothesis
Corneal blink reflex: trigeminal nerve senses, facial nerve motors to blink at bright light or loud sound or irritating particle in eye.
Corneal reflex
Accomodation reflex
Pupillary light reflex
-
Pigmentation in desert lizards
white lizards
Pigmentation in humans: Baltic blonde & blue eyes from Gulf stream & grain?
pigment
"There is only one spot on the planet where grains will grow despite sub-arctic sunlight.
It is where the warm waters of the Gulf Stream wash ashore. The Baltic is the only place on earth where ocean currents keep it warm enough to grow grain despite dim sunlight. When the inhabitants of this region switched to grain about 6 KYA, they suddenly got insufficient vitamin D to survive. They had stopped eating mostly meat and fish in a place where sunlight was too dim to produce vitamin D in normally pigmented skin. And so they adapted by retaining into adulthood the infantile trait of extreme paleness. Blonde hair and blue eyes were other infantile traits that were just swept along accidentally."
Why did they shift from hunting/gathering (grain processing sorghum in Mozambique 100ka) to complete absolute dependence on grain? What about their cattle/goats/dogs? Fishing seems to have increased rather than decreased amongst Baltic sea peoples with better boat/net technology. Camouflage is always important, whether for predator, prey or combat, but less for farmers. Clothing in cold? Baltic was warm in winter? Europeans also adapted by retaining the ability to digest lactose in adulthood, obtaining vitamin D from milk.
-
Medieval rural Briton women had wider thicker bones than city women
http://www.guardian.co.uk/science/2009/dec/17/women-yorkshire-archeaology-find
Language evolution
http://schott.blogs.nytimes.com/2009/12/16/q-and-a-the-death-of-languages/
-
Whale fossil 4.5ma in Spain: deposited on seafloor 50m deep, now 80m above ground 24km inland. So 4.5ma Medit was high, or tectonic uplifting or both.
http://www.sciencedaily.com/releases/2009/12/091215101716.htm
Dwarf suction-feeding Australian baleen whale
http://news.bbc.co.uk/2/hi/science/nature/8430402.stm
Tuesday, December 22, 2009
Monday, December 21, 2009
Bittersweet: genes for taste
The bitter taster gene, I hadn't known that it is stronger in some groups. How does it fit with increased eating of mint/mustard? Cooking? Adding salt? Alcohol? Fermented milk vs fresh milk - lactase persistence? PTC/PROP? Malaria?
Some Neandertals and some humans lack it, some have multiple copies.
http://www.newscientist.com/article/dn16335-genes-give-africans-a-better-sense-of-taste.html
New research suggests that Africans have more sensitive palates than Europeans and Asians - at least for bitter tastes. A survey of numerous African populations in Kenya and Cameroon found a striking amount of diversity in a gene responsible for sensing bitter tastes. "If they have more genetic diversity, there's more variation in their ability to taste," says Sarah Tishkoff, a geneticist at the University of Pennsylvania in Philadelphia, who presented the findings at a recent conference. Europeans and Asians typically have only one of two forms of a gene called TAS2R38, which detects a bitter-tasting compound called PTC and similar chemicals in vegetables such as broccoli and Brussels sprouts. The gene makes the difference between people tasting a weak dilution of the compound or not, with little nuance in between.
However, the compounds that cause bitter tastes can be thyroid-damaging, notes Paul Breslin, a neuroscientist at Monell Chemical Senses Center in Philadelphia. If you have a healthy thyroid you want to eat these things because they're packed with vitamins, he says. [Cooking?]
Seafood benefits : A diet high in iodine - common in coastal-dwelling people - protects against such thyroid damage, but, iodine intake typically drops off the further people live from the ocean. So bitter-sensitive genes could help these people avoid toxic veggies, Breslin speculates. Tishkoff wonders why, then, Europeans lost some the ability to sense bitterness. Different diets and evolutionary forces offer one explanation, she says. Their lack of bitter taste diversity could also be due to a paucity of genetic variation in the small number of African migrants that became ancestors to the Europeans. In general, sub-Saharan Africans boast more genetic diversity than people native to Europe and other continents.
Avoiding potentially toxic plants might not be the only reason for diversity in bitter taste genes, says Theodore Schurr, an anthropologist at the University of Pennsylvania, who was not involved in the study. His team found lots of variation in bitter taste genes in a Siberian population that has historically eaten few vegetables.
http://www.newscientist.com/article/dn6668-genetic-variation-gives-a-taste-for-alcohol.html
People with a gene variation that dulls their taste buds to bitter flavours drink twice as much alcohol as those with more sensitive palates, suggests a US study. The bitter chemical 6-n-propylthiouracil (PROP) is often used in taste tests and in 2003 a gene influencing the sensitivity to PROP was discovered. The gene, TAS2R38, codes for a taste bud receptor and has several natural variations.
TAS2R38. About half of the world's population have at least one copy of the low-sensitivity variant AVI, he says.
A new study of ancient DNA offers preliminary support for that conclusion. Neanderthals possessed a gene mutation that would have meant they couldn't taste bitter chemicals found in many plants. There has been speculation that this mutation, which occurs in a taste receptor gene called TAS2R38, is beneficial to humans because it makes vitamin-packed vegetables more palatable. It probably arose in the common ancestor of modern humans and Neanderthals more than a million years ago. The gene encodes a receptor that detects a chemical called phenylthiocarbamide, which is closely related to compounds produced by broccoli, cabbage and Brussels sprouts.
http://www.newscientist.com/article/dn17595-seafood-gave-us-the-edge-on-the-neanderthals.html
He and colleague Erik Trinkaus at Washington University in St Louis, Missouri, compiled chemical measurements taken from bone collagen protein belonging to 13 Neanderthals and 13 modern humans, all recovered in Europe. They also added data collected from a 40,000-year-old human recovered in Romania's Oase cave.
Because our bones are constantly destroyed and rebuilt while we are alive, the atoms that make up collagen hold a record of what we've eaten. "When you take a sample of a bone you're getting all those breakfasts, lunches and dinners for 20 years," Richards says.
Telltale atoms
Measurements of the abundance of heavy isotopes of carbon and nitrogen hold the key. Marine environments contain a higher proportion of heavy carbon atoms (carbon-13) than land ecosystems, so lots of carbon-13 in the recovered collagen points to a seafood diet. Meanwhile, heavy nitrogen (nitrogen-15) tends to build up as the atom moves up the food chain, from plants to herbivores to carnivores.
High levels of heavy nitrogen can also come from a diet with lots of freshwater fish. Aquatic food webs tend to contain more steps than terrestrial ecosystems, so large fish often have higher levels of heavy nitrogen than land predators.
-
A very unusual mammal: the short tailed shrew, echolocates, clicks, venomous, cannibalistic...
http://en.wikipedia.org/wiki/Northern_Short-tailed_Shrew
Some Neandertals and some humans lack it, some have multiple copies.
http://www.newscientist.com/article/dn16335-genes-give-africans-a-better-sense-of-taste.html
New research suggests that Africans have more sensitive palates than Europeans and Asians - at least for bitter tastes. A survey of numerous African populations in Kenya and Cameroon found a striking amount of diversity in a gene responsible for sensing bitter tastes. "If they have more genetic diversity, there's more variation in their ability to taste," says Sarah Tishkoff, a geneticist at the University of Pennsylvania in Philadelphia, who presented the findings at a recent conference. Europeans and Asians typically have only one of two forms of a gene called TAS2R38, which detects a bitter-tasting compound called PTC and similar chemicals in vegetables such as broccoli and Brussels sprouts. The gene makes the difference between people tasting a weak dilution of the compound or not, with little nuance in between.
However, the compounds that cause bitter tastes can be thyroid-damaging, notes Paul Breslin, a neuroscientist at Monell Chemical Senses Center in Philadelphia. If you have a healthy thyroid you want to eat these things because they're packed with vitamins, he says. [Cooking?]
Seafood benefits : A diet high in iodine - common in coastal-dwelling people - protects against such thyroid damage, but, iodine intake typically drops off the further people live from the ocean. So bitter-sensitive genes could help these people avoid toxic veggies, Breslin speculates. Tishkoff wonders why, then, Europeans lost some the ability to sense bitterness. Different diets and evolutionary forces offer one explanation, she says. Their lack of bitter taste diversity could also be due to a paucity of genetic variation in the small number of African migrants that became ancestors to the Europeans. In general, sub-Saharan Africans boast more genetic diversity than people native to Europe and other continents.
Avoiding potentially toxic plants might not be the only reason for diversity in bitter taste genes, says Theodore Schurr, an anthropologist at the University of Pennsylvania, who was not involved in the study. His team found lots of variation in bitter taste genes in a Siberian population that has historically eaten few vegetables.
http://www.newscientist.com/article/dn6668-genetic-variation-gives-a-taste-for-alcohol.html
People with a gene variation that dulls their taste buds to bitter flavours drink twice as much alcohol as those with more sensitive palates, suggests a US study. The bitter chemical 6-n-propylthiouracil (PROP) is often used in taste tests and in 2003 a gene influencing the sensitivity to PROP was discovered. The gene, TAS2R38, codes for a taste bud receptor and has several natural variations.
TAS2R38. About half of the world's population have at least one copy of the low-sensitivity variant AVI, he says.
A new study of ancient DNA offers preliminary support for that conclusion. Neanderthals possessed a gene mutation that would have meant they couldn't taste bitter chemicals found in many plants. There has been speculation that this mutation, which occurs in a taste receptor gene called TAS2R38, is beneficial to humans because it makes vitamin-packed vegetables more palatable. It probably arose in the common ancestor of modern humans and Neanderthals more than a million years ago. The gene encodes a receptor that detects a chemical called phenylthiocarbamide, which is closely related to compounds produced by broccoli, cabbage and Brussels sprouts.
http://www.newscientist.com/article/dn17595-seafood-gave-us-the-edge-on-the-neanderthals.html
He and colleague Erik Trinkaus at Washington University in St Louis, Missouri, compiled chemical measurements taken from bone collagen protein belonging to 13 Neanderthals and 13 modern humans, all recovered in Europe. They also added data collected from a 40,000-year-old human recovered in Romania's Oase cave.
Because our bones are constantly destroyed and rebuilt while we are alive, the atoms that make up collagen hold a record of what we've eaten. "When you take a sample of a bone you're getting all those breakfasts, lunches and dinners for 20 years," Richards says.
Telltale atoms
Measurements of the abundance of heavy isotopes of carbon and nitrogen hold the key. Marine environments contain a higher proportion of heavy carbon atoms (carbon-13) than land ecosystems, so lots of carbon-13 in the recovered collagen points to a seafood diet. Meanwhile, heavy nitrogen (nitrogen-15) tends to build up as the atom moves up the food chain, from plants to herbivores to carnivores.
High levels of heavy nitrogen can also come from a diet with lots of freshwater fish. Aquatic food webs tend to contain more steps than terrestrial ecosystems, so large fish often have higher levels of heavy nitrogen than land predators.
-
A very unusual mammal: the short tailed shrew, echolocates, clicks, venomous, cannibalistic...
http://en.wikipedia.org/wiki/Northern_Short-tailed_Shrew
Wednesday, December 16, 2009
Skull density in hominids
Gauld SC 1996 AJPA 100:411-426
Allometric patterns of cranial bone thickness in fossil hominids
Skull thickness in He is more than twice that of other primates of
comparable body size, Hn is intermediate, Hs is still above most other
primates, and A.africanus is somewhat above other equally-sized primates,
but I need more figures of other apiths, esp. robust ones.
Extraordinarily thick skull vaults are typically (AFAIK exclusively) seen in
shallow slow parttime diving animals. Slow divers in sea water (density c
1.024) are expected to have much thicker skulls than those in freshwater.
Alan Shabel found that in dentitions & enamel thickness apiths resembled
mungoes & other carnivores that fed (partly) on hard-shelled invertebrates.
Might africanus (& other apiths??) have parttime dived (or ducked) for
bottom shell+crayfish in the wetlands & swamp forests where they lived??
We need a lot more measurements of skull thicknesses esp. of fossil
hominids, but also of other animals.
I made a graph (somebody did it for me) with
- x-axis = the cubic root of the body weight of different primate spp,
- y-axis = their skull thickness.
It was almost a straight line, with small spp a bit below that line,
medium-sized a bit above (esp.orang & chimp), and very large ones (gorilla)
a bit lower.
But there were 3 obvious exceptions:
- He was far above that line (but it might have been heavier than the usual
estimation of c 50 kg),
- Hs was clearly above it,
- A.africanus was also clearly above it (depending on its body weight, which
might be a bit higher IMO than usu.estimated).
Other data suggest Hn was intermediate between He & Hn, but I still lack
enough comparable data on apiths, Ardipith etc.
Does anybody know where to find more data? MV @ AAT
-
This fits the pattern -
early hominoid, foraging on pond surface AHV aquatic herbs, congo lowland gorillas raking high-protein hydrocharis and yanking up sedges for their rhyzomes, not dunking their faces nor seeking benthic foods, with large inflatable laryngeal air sacs for partial flotation, with lightweight skulls. Apith afarensis similar, but in Rift valley, less fruit trees, more sedges.
Apith africanus ate more water lily rhyzomes, reaching below water so smaller air sacs and denser skull, more invertebrate foods crayfish/snails and small vertebrates, more high fruit trees. Rift - So. Africa shallow lakes?
Human ancestors similar, but more tidal saltwater, lost air sacs and gained dense skull, ate tidal mangrove oysters at lagoons, more shrub berries, less high fruit trees, Medit. zone?
-
Myrica gale is a flowering plant native to Europe, with sweet resinous scent, and is a traditional insect repellent, used by campers to keep biting insects out of tents. Sweet Gale can grow in a narrow band in the intertidal zone, especially if it has some logs, washed down into the estuary on which to establish itself. It is a favorite food of beavers and low beaver dams can be found in the intertidal zone if sufficient sweet gale is present. The ponds thus formed are often completely submerged at high tide but retain water at low tide and provide deep enough water to provide a refuge for fish, including juvenile salmon where the water is too deep for predation by wading birds. wiki
-
Ear wax & Scent: Difference of appocrine sweat glands in Europeans, Africans and Asians
scent, ear wax
rice, milk, alcohol in ancient Eurasians
-
Gorilla hybrids, Ardi party @ Lawnchair anthropology
-
Molars in hominoids
Gorilla and chimp molars evert earlier than orang and human due to more forest ground foraging (parallel with knucklewalking), orang probably has primitive hominoid condition, human also but even more so do to beaver lodge - hut/cave nesting & aquatic foraging & mainly food processing & cooking.
Speaking of dense bones and waterside herbivores, article on neolithic dugong & fishing rituals:
http://gulfnews.com/news/gulf/uae/general/excavation-uncovers-ritual-site-1.523925
Allometric patterns of cranial bone thickness in fossil hominids
Skull thickness in He is more than twice that of other primates of
comparable body size, Hn is intermediate, Hs is still above most other
primates, and A.africanus is somewhat above other equally-sized primates,
but I need more figures of other apiths, esp. robust ones.
Extraordinarily thick skull vaults are typically (AFAIK exclusively) seen in
shallow slow parttime diving animals. Slow divers in sea water (density c
1.024) are expected to have much thicker skulls than those in freshwater.
Alan Shabel found that in dentitions & enamel thickness apiths resembled
mungoes & other carnivores that fed (partly) on hard-shelled invertebrates.
Might africanus (& other apiths??) have parttime dived (or ducked) for
bottom shell+crayfish in the wetlands & swamp forests where they lived??
We need a lot more measurements of skull thicknesses esp. of fossil
hominids, but also of other animals.
I made a graph (somebody did it for me) with
- x-axis = the cubic root of the body weight of different primate spp,
- y-axis = their skull thickness.
It was almost a straight line, with small spp a bit below that line,
medium-sized a bit above (esp.orang & chimp), and very large ones (gorilla)
a bit lower.
But there were 3 obvious exceptions:
- He was far above that line (but it might have been heavier than the usual
estimation of c 50 kg),
- Hs was clearly above it,
- A.africanus was also clearly above it (depending on its body weight, which
might be a bit higher IMO than usu.estimated).
Other data suggest Hn was intermediate between He & Hn, but I still lack
enough comparable data on apiths, Ardipith etc.
Does anybody know where to find more data? MV @ AAT
-
This fits the pattern -
early hominoid, foraging on pond surface AHV aquatic herbs, congo lowland gorillas raking high-protein hydrocharis and yanking up sedges for their rhyzomes, not dunking their faces nor seeking benthic foods, with large inflatable laryngeal air sacs for partial flotation, with lightweight skulls. Apith afarensis similar, but in Rift valley, less fruit trees, more sedges.
Apith africanus ate more water lily rhyzomes, reaching below water so smaller air sacs and denser skull, more invertebrate foods crayfish/snails and small vertebrates, more high fruit trees. Rift - So. Africa shallow lakes?
Human ancestors similar, but more tidal saltwater, lost air sacs and gained dense skull, ate tidal mangrove oysters at lagoons, more shrub berries, less high fruit trees, Medit. zone?
-
Myrica gale is a flowering plant native to Europe, with sweet resinous scent, and is a traditional insect repellent, used by campers to keep biting insects out of tents. Sweet Gale can grow in a narrow band in the intertidal zone, especially if it has some logs, washed down into the estuary on which to establish itself. It is a favorite food of beavers and low beaver dams can be found in the intertidal zone if sufficient sweet gale is present. The ponds thus formed are often completely submerged at high tide but retain water at low tide and provide deep enough water to provide a refuge for fish, including juvenile salmon where the water is too deep for predation by wading birds. wiki
-
Ear wax & Scent: Difference of appocrine sweat glands in Europeans, Africans and Asians
scent, ear wax
rice, milk, alcohol in ancient Eurasians
-
Gorilla hybrids, Ardi party @ Lawnchair anthropology
-
Molars in hominoids
Gorilla and chimp molars evert earlier than orang and human due to more forest ground foraging (parallel with knucklewalking), orang probably has primitive hominoid condition, human also but even more so do to beaver lodge - hut/cave nesting & aquatic foraging & mainly food processing & cooking.
Speaking of dense bones and waterside herbivores, article on neolithic dugong & fishing rituals:
http://gulfnews.com/news/gulf/uae/general/excavation-uncovers-ritual-site-1.523925
Monday, December 14, 2009
Natural mosquito repellents
Bog Myrtle/Myrica Gale
Myrica gale is a species of flowering plant in the genus Myrica, native to northern and western Europe and parts of northern North America. The foliage has a sweet resinous scent, and is a traditional insect repellent, used by campers to keep biting insects out of tents.It is also marketed by Totally Herby of Scotland [3] as an insect repellent, and by The Highland Soap Company [4] as a soap.In Scotland it has been traditionally used to ward off the dreaded midge.Sweet Gale can grow in a narrow band in the intertidal zone, especially if it has some logs, washed down into the estuary on which to establish itself. It is a favorite food of beavers and low beaver dams can be found in the intertidal zone if sufficient sweet gale is present. The ponds thus formed are often completely submerged at high tide but retain water at low tide and provide deep enough water to provide a refuge for fish, including juvenile salmon where the water is too deep for predation by wading birds. Thus the presence of Sweet Gale can enhance salmon recruitment. Myrica gale is listed as an abortifacient and, therefore, should not be consumed by women who are, or might be, pregnant.[6][7] wikipedia
Swedish scientists have found that Achillea_millefolium/ yarrow extract repels mosquitoes.[1]
A Thai study found both clove oil and celery seed extract to be effective mosquito repellants:
study
Carvacrol Carvacrol inhibits the growth of several bacteria strains, e.g. Escherichia coli[5] and Bacillus cereus. Its low toxicity together with its pleasant taste and smell suggests its use as a food additive to prevent bacterial contamination.
The cause of the antimicrobial properties is believed to be disruption of the bacteria membrane.
It is a potent activator of the human ion channels transient receptor potential V3 (TRPV3) and A1 (TRPA1).
Physiology of TRPV3 channel: TRPV3, is a human gene encoding the protein of the same name.
The TRPV3 protein belongs to a family of nonselective cation channels that function in a variety of processes, including temperature sensation and vasoregulation. The thermosensitive members of this family are expressed in subsets of sensory neurons that terminate in the skin, and are activated at distinct physiological temperatures. This channel is activated at temperatures between 22 and 40 degrees C.
The TRPV3 channel is widely expressed in the human body, especially in the skin in keratinocytes, but also in the brain. It functions as a molecular sensor for innocuous warm temperatures.[2] Mice lacking these protein are unable to sense elevated temperatures (>33 °C) but are able to sense cold and noxious heat.[3] In addition to thermosenstation TRPV3 channels seem to play a role in hair growth because mutations in the TRPV3 gene cause hair loss in mice.[4] The role of TRPV3 channels in the brain is unclear.
The TRPV3 channel is directly activated by various natural compounds like carvacrol, thymol and eugenol.[5] Several other monoterpenoids which cause either feeling of warmth or are skin sensitizers can also open the channel.
Herbal insect repellents (caution, see medical information for possible side-effects)
insect repellents
* Achillea alpina (mosquitos)
* alpha-terpinene (mosquitos)[17]
* Basil[18] Further information: Ocimum basilicum
* Callicarpa americana (Beautyberry)[19]
* Camphor (moths)[20]
* Carvacrol (mosquitos)[17]
* Castor oil (Ricinus communis) (mosquitos)[21]
* Catnip oil (Nepeta species) (nepetalactone against mosquitos)[22]
* Cedar oil (mosquitos)[21]
* Celery extract (Apium graveolens) (mosquitos)
* Cinnamon[24] (leaf oil kills mosquito larvae)[25]
* Citronella oil (repels mosquitos)[21]
* Clove oil (mosquitoes)[21]
* Eucalyptus oil (70%+ eucalyptol), (cineol is a synonym), mosquitos, flies, dust mites[26])
* Fennel oil (Foeniculum vulgare) (mosquitos)[17]
* Garlic (Allium sativum) (rice weevil, wheat flour beetle)[27] (NB: a dose similar to the one as a food ingredient should be used for the time being)
* Geranium oil (also known as Pelargonium graveolens) [28], [21]
* Lavender[29][30]
* Lemon eucalyptus (Corymbia citriodora) essential oil and its active ingredient p-menthane-3,8-diol (PMD)
* Lemongrass oil (Cymbopogon species) (mosquitos)[21]
* Marigolds (Tagetes species)
* Marjoram (Spider mites Tetranychus urticae and Eutetranychus orientalis)[32]
* Neem oil (Azadirachta indica) (Repels or kills mosquitos, their larvae and a plethora of other insects including those in agriculture)
* Peppermint (Mentha x piperita) (mosquitos)[34]
* Pennyroyal (Mentha pulegium) (mosquitos,[26] fleas[35]), but very toxic to pets.[35]
* Pyrethrum (from Chrysanthemum species, particularly C. cinerariifolium and C. coccineum)
* Rosemary (Rosmarinus officinalis) [32] (mosquitos)[21]
* Spanish Flag Lantana camara (against Tea Mosquito Bug, Helopeltis theivora) [36]
* Solanum villosum berry juice (against Stegomyia aegypti mosquitos)[37]
* Tea tree[38]
* Thyme (Thymus species)(mosquitos)[17]
Also note that chimps consume noxious herbs to remove stomach parasites, capuchin monkeys rub citrus rinds on their backs to protect against insects, and spider monkeys use twigs/chewed foliage as body rubs. http://dsc.discovery.com/news/2009/07/31/spider-monkey-scratcher.html
-
Butterfly wings & typhoon probability
flap
These proponents of chaos theory never mention that flying insects/birds/bats cause stratified gases in sub-canopy humid rainforests to mix, improving photosynthesis & respiration efficiency.
Ants & plants: plants control guardian ants with chemicals, repellants & food
ants & plants
Cycads (pre-conifers) & thrips (ant-like), chemicals attract & repulse, push-pull pollination
cycad attraction/repulsion
flower color changes
Myrica gale is a species of flowering plant in the genus Myrica, native to northern and western Europe and parts of northern North America. The foliage has a sweet resinous scent, and is a traditional insect repellent, used by campers to keep biting insects out of tents.It is also marketed by Totally Herby of Scotland [3] as an insect repellent, and by The Highland Soap Company [4] as a soap.In Scotland it has been traditionally used to ward off the dreaded midge.Sweet Gale can grow in a narrow band in the intertidal zone, especially if it has some logs, washed down into the estuary on which to establish itself. It is a favorite food of beavers and low beaver dams can be found in the intertidal zone if sufficient sweet gale is present. The ponds thus formed are often completely submerged at high tide but retain water at low tide and provide deep enough water to provide a refuge for fish, including juvenile salmon where the water is too deep for predation by wading birds. Thus the presence of Sweet Gale can enhance salmon recruitment. Myrica gale is listed as an abortifacient and, therefore, should not be consumed by women who are, or might be, pregnant.[6][7] wikipedia
Swedish scientists have found that Achillea_millefolium/ yarrow extract repels mosquitoes.[1]
A Thai study found both clove oil and celery seed extract to be effective mosquito repellants:
study
Carvacrol Carvacrol inhibits the growth of several bacteria strains, e.g. Escherichia coli[5] and Bacillus cereus. Its low toxicity together with its pleasant taste and smell suggests its use as a food additive to prevent bacterial contamination.
The cause of the antimicrobial properties is believed to be disruption of the bacteria membrane.
It is a potent activator of the human ion channels transient receptor potential V3 (TRPV3) and A1 (TRPA1).
Physiology of TRPV3 channel: TRPV3, is a human gene encoding the protein of the same name.
The TRPV3 protein belongs to a family of nonselective cation channels that function in a variety of processes, including temperature sensation and vasoregulation. The thermosensitive members of this family are expressed in subsets of sensory neurons that terminate in the skin, and are activated at distinct physiological temperatures. This channel is activated at temperatures between 22 and 40 degrees C.
The TRPV3 channel is widely expressed in the human body, especially in the skin in keratinocytes, but also in the brain. It functions as a molecular sensor for innocuous warm temperatures.[2] Mice lacking these protein are unable to sense elevated temperatures (>33 °C) but are able to sense cold and noxious heat.[3] In addition to thermosenstation TRPV3 channels seem to play a role in hair growth because mutations in the TRPV3 gene cause hair loss in mice.[4] The role of TRPV3 channels in the brain is unclear.
The TRPV3 channel is directly activated by various natural compounds like carvacrol, thymol and eugenol.[5] Several other monoterpenoids which cause either feeling of warmth or are skin sensitizers can also open the channel.
Herbal insect repellents (caution, see medical information for possible side-effects)
insect repellents
* Achillea alpina (mosquitos)
* alpha-terpinene (mosquitos)[17]
* Basil[18] Further information: Ocimum basilicum
* Callicarpa americana (Beautyberry)[19]
* Camphor (moths)[20]
* Carvacrol (mosquitos)[17]
* Castor oil (Ricinus communis) (mosquitos)[21]
* Catnip oil (Nepeta species) (nepetalactone against mosquitos)[22]
* Cedar oil (mosquitos)[21]
* Celery extract (Apium graveolens) (mosquitos)
* Cinnamon[24] (leaf oil kills mosquito larvae)[25]
* Citronella oil (repels mosquitos)[21]
* Clove oil (mosquitoes)[21]
* Eucalyptus oil (70%+ eucalyptol), (cineol is a synonym), mosquitos, flies, dust mites[26])
* Fennel oil (Foeniculum vulgare) (mosquitos)[17]
* Garlic (Allium sativum) (rice weevil, wheat flour beetle)[27] (NB: a dose similar to the one as a food ingredient should be used for the time being)
* Geranium oil (also known as Pelargonium graveolens) [28], [21]
* Lavender[29][30]
* Lemon eucalyptus (Corymbia citriodora) essential oil and its active ingredient p-menthane-3,8-diol (PMD)
* Lemongrass oil (Cymbopogon species) (mosquitos)[21]
* Marigolds (Tagetes species)
* Marjoram (Spider mites Tetranychus urticae and Eutetranychus orientalis)[32]
* Neem oil (Azadirachta indica) (Repels or kills mosquitos, their larvae and a plethora of other insects including those in agriculture)
* Peppermint (Mentha x piperita) (mosquitos)[34]
* Pennyroyal (Mentha pulegium) (mosquitos,[26] fleas[35]), but very toxic to pets.[35]
* Pyrethrum (from Chrysanthemum species, particularly C. cinerariifolium and C. coccineum)
* Rosemary (Rosmarinus officinalis) [32] (mosquitos)[21]
* Spanish Flag Lantana camara (against Tea Mosquito Bug, Helopeltis theivora) [36]
* Solanum villosum berry juice (against Stegomyia aegypti mosquitos)[37]
* Tea tree[38]
* Thyme (Thymus species)(mosquitos)[17]
Also note that chimps consume noxious herbs to remove stomach parasites, capuchin monkeys rub citrus rinds on their backs to protect against insects, and spider monkeys use twigs/chewed foliage as body rubs. http://dsc.discovery.com/news/2009/07/31/spider-monkey-scratcher.html
-
Butterfly wings & typhoon probability
flap
These proponents of chaos theory never mention that flying insects/birds/bats cause stratified gases in sub-canopy humid rainforests to mix, improving photosynthesis & respiration efficiency.
Ants & plants: plants control guardian ants with chemicals, repellants & food
ants & plants
Cycads (pre-conifers) & thrips (ant-like), chemicals attract & repulse, push-pull pollination
cycad attraction/repulsion
flower color changes
Saturday, December 12, 2009
100ka India (tubers) to 10ka China (rice) migration
http://scienceblogs.com/gnxp/2009/12/are_chinese_subsets_of_southea.php?utm_source=editorspicks
Actually, I think 120ka Hs was thinly distributed along coasts and river valleys throughout the tropics from the East African Rift and coast, then 74ka Mt Toba exploded killing many around India, so from Papua some went to Malaya and split to west to India or east to China, while some from N Africa/Rift went east to Arabia/Iran/Caspian... tough call.
-
Interesting, grain seeds were cut with stone tools 105ka in Mozambique:
http://tech.groups.yahoo.com/group/AAT/message/55114
750ka Jordan Valley site shows use of waterside flora/fauna:
http://tech.groups.yahoo.com/group/AAT/message/55115
-
From Africa to India 100ka, from India to China 10ka
Scientists rejig human evolution, Indians ancestors of East Asians
Africa-India-China
Calcutta News.Net
Friday 11th December, 2009 (IANS)
The ancestors of the present-day populations of China, Japan and other east Asian countries had migrated from India, scientists from 10 countries including India said Friday after achieving a breakthrough in the study of the evolution of humans and their spread across the world. This large study establishes that ancient Indian population was a source of ancestors of Japanese, Chinese and all other East Asians... Samir Brahmachari, director general of the Council for Scientific and Industrial Research (CSIR) told IANS Friday. According to the study, people from India moved to southeast Asia and east Asia. 'They all have a common genetic origin. It shows that India represents a microcosm of Asia's genetic diversity,' Brahmachari, who was a key researcher in this study, later informed media persons here. Scientists said that earlier it was believed that several groups of people from Africa entered India, China, Japan and other eastern Asian regions separately.
'But this study now negates them all. There was only a single group of entry from southern Africa to India around 100,000 years ago. They entered India through land but in and around the coastal belt. They slowly spread to southern India and moved to south east and east Asian regions,' the CSIR chief added. He said these Indians and their genetic mutation variety slowly migrated to other parts of Asia. 'This will give a new meaning to human evolution theory and its spread.' The study, which traces the 'genetic origins of Asian population' was conducted by 90 scientists from 10 countries in over 30 scientific institutions. At least 10 scientists from three key Indian science research labs were part of the study.
It took five years for these top scientists to come up with these new findings which will pave the way for more historical, medical and anthropological studies. Congratulating Indian scientists and the 'path breaking study', Science and Technology Minister Prithviraj Chavan said: 'It has important implications, in furthering the understanding of migratory patterns in human history and for the study of genetics and diseases.'
It also has political ramifications, he noted. 'In spite of many political differences, these Asian nations worked together to produce such a study that has wide implication on the origin of people. The study suggest that there was a single initial entry into the continent of Asia, instead of multiple inflows,' Chavan added.
-
Taiwan not homeland of Austronesians?
"In addition, the topology of the maximum-likelihood population tree (Fig. 1)
seems to suggest that Taiwan aborigines may be derived from, rather than
ancestral to other Austronesian populations, because they occupy central, rather
than peripheral positions within the cluster of Austronesian speaking
populations. This observation seems to contradict a commonly cited Taiwan
"homeland" hypothesis of Austronesian populations. Given a nearly total lack of
prior autosomal data from Southeast Asian populations (9, 10), and conflicting
evidence based on mtDNA analyses, some of which questions the Taiwan homeland
story...
The scientists also reported a clear increase in genetic diversity from northern to southern latitudes. Their findings also suggest that there was one major inflow of human migration into Asia arising from Southeast Asia, rather than multiple inflows from both southern and northern routes as previously proposed. This indicates that Southeast Asia was the major geographic source of East Asian and North Asian populations.
(A figure illustrating the paper shows plausible routes of pre-historical migration of Asian human populations. According to the study, the PanAsia SNP Initiative, the most recent common ancestors of Asians arrived first in India and later, some of them migrated to Thailand, and South to the lands known today as Malaysia, Indonesia, and the Philippines. The first group of settlers must have gone very far south before they settled successfully. These included the Malay Negritos , Philippine Negritos , the East Indonesians, and early settlers of the Pacific Islands. Thereafter, one or several groups of people migrated North, mixed with previous settlers there and, finally, formed various populations we now refer to as Austronesian, Austro-Asiatic, Tai-Kadai, Hmong-Mien, and Altaic. The figure is titled, "Putative Pre-Historical Migration Routes of Asian Human Populations.")
http://www.eurekalert.org/pub_releases/2009-12/afst-gah120909.php
"…More than 90% of East Asian (EA) haplotypes could be found in either Southeast Asian (SEA) or Central-South Asian (CSA) populations and show clinal structure with haplotype diversity decreasing from south to north. Furthermore, 50% of EA haplotypes were found in SEA only and 5% were found in CSA only, indicating that SEA was a major geographic source of EA populations…"
"…The geographic source(s) contributing to EA populations have long been debated. One hypothesis
suggests that all SEA and EA populations derive primarily from a single initial migration,
which entered the continent along a southern, largely coastal route (19, 20). Another hypothesis
argues for at least two independent migrations into East Asia, first along a southern route, followed later by a series of migrations along a more northern route that served to bridge European and EA populations, but with little contribution to populations in Southeast Asia…"
"…the evidence from our autosomal data and the accompanying simulation studies (figs.
S29 and S30) point toward a history that unites the Negrito and non-Negrito populations of Southeast and East Asia via a single primary wave of entry of humans into the continent…"
India centre of Asian evolution?
NDTV Correspondant, Friday December 11, 2009, New Delhi
How did Asian populations evolve? Did they come from Europe, were they native to Asia? A new study that mapped human diversity across Asian nations reinforces an older controversial theory that after human beings first evolved in Africa, they possibly migrated to India via the land and sea routes. So out of Africa, India became the melting pot where humans evolved and then slowly spread all over Asia. This also means that after Africa some of the oldest living populations of humans can be found in India. Some of the tribes in the Andaman and Nicobar Islands the Jarawas, Onges and Great Andamanese are the closest relative mans ancestors.
-
Out of Africa to China: African Eve of Chinese
All modern humans are descended from a 200,000-year-old African woman. In 1987 the New Zealander Allan Charles Wilson and Rebecca Cann published a study of mitochondrial DNA that supported the "African Eve" theory that all human beings living today are descendents of a single woman who lived in Africa around 200,000 years ago. According to Wilson and Cann descendents of this "African Eve" migrated around the world and later evolved into the different varieties of modern humans. Since then more and more genetic evidence has accumulated, all supporting the view that modern humans, including Chinese people, originated from a single population in Africa. In 1998, Chinese scientist Chu Jiayou and his team analyzed the DNA microsatellites (also known as simple sequence repeats) of northern and southern Chinese, both those of Han and ethnic minorities. Chu concluded that the ancestors of the modern Chinese had migrated to China from Africa via South Asia. As the mutation rate of DNA microsatellites is high, it is not the best method available for researching ancient human migration and the evolution process. Su Bing and other scientists from the Kunming Institute of Zoology proposed an alternative approach using single nucleotide polymorphism (SNP) in the Y-chromosome (Y-SNP). This was the approach used by Prof. Jin Li and associate professor Li Hui.
DNA molecules point to a startling conclusion: Jin chose the Y-chromosome because it is relatively pure from a genetic perspective. Human beings have two sets of chromosomes, X and Y, inherited from our mothers and fathers respectively. The Y-chromosome comes from male and has a low mutation rate. It reflects how human genes are passed on from generation to generation more clearly than the X chromosome. As a result, geneticists see it as ideal material for the study of human origins. Jin and his team focused on three SNPs on the Y-chromosome M89, M130 and YAP. They are mutations of another mutated DNA molecule M168, which originated in Africa between 31,000 and 79,000 years ago.
"M168 originated only in East Africans. All people outside Africa and some Africans still have it. So it is the most direct evidence to prove that modern humans came from Africa." Jin wrote in his paper. How do scientists work out the age of a DNA component? How do scientists know M168 existed in ancient Africa? How do they work out exactly when it originated? Associate Professor Li Hui said that non-genic DNA sequences are used in molecular anthropology because genes possess many physiological functions. If a gene mutates, a person's health may be greatly affected. There are two fundamental features of the materials Jin and his team chose: they were non-genic and genetic haploid. Mitochondrial DNA and Y-chromosomes belong to this category. Most of the Y-chromosome consists of non-genic sequences. The team analyzed two types of mutation of the non-genic sequence. The first was SNP. This type of mutation is rare and stable. It will not repeat or change back to its original form. The structural relationships of all types of Y-chromosome all over the world are based on this feature. The other type of mutation was short tandem repeats (STR). These lengthen and shorten at a constant speed. Thus the origin of each type of Y chromosome can be dated by dividing the total number of mutations by the rate of mutation.
In other words analysis of SNP and SRT mutations show when the M168 mutation occurred. DNA from modern Chinese proves their African origins. Jin Li and his team randomly selected 9,988 Chinese males as samples. They found that all samples of M89, M130, and YAP led to only three mutations. 9,329 samples (93.4 percent) mutated into M89T0M130C and YAP-; 370 samples (3.7 percent) mutated into M89C0M130T and YAP-. 290 samples (2.9 percent) mutated into M89C0M130C and YAP+. No new mutation was found. The results coincided with findings in other parts of the world, that is, M168 displayed no new mutations in China. The result proved that Chinese people must have come from Africa, along with all other modern humans. But Jin Li's research also supported the African origin theory from another perspective, which was beyond their original expectations.
Tracing human migration routes using DNA: Besides trying to find evidence to prove one way or another whether Chinese people had an independent origin, Jin and his team wanted to study the genetic differences among people living in different parts of China by investigating the distribution frequency of the three ancient Y-chromosomes.
The molecular genetic structure of each ethnic group has its own particular characteristics. By analyzing the mutation process of M89, M130 and YAP, they figured out the distribution and migration routes of the different ethnic groups in China. For example, most samples that mutated into M89T, M130C and YAP- were from Han Chinese individuals. The other two types of mutation were more common in ethnic minorities.
Li Hui tested his own DNA to see where his ancestors came from. His Y-chromosome is type 01, which originated around Beibu Bay and the west of Hainan Province about 20,000 years ago. Type 01 then traveled to Guangdong, Taiwan and Fujian about 10,000 years ago and moved to the coastal areas of Jiangsu and Zhejiang 8,000 years ago. So Li's ancestors must have followed the same route.
Scientists use similar methods to tell how the original Africans migrated around the world. Li Shilin, a teacher at RCCASFU, says human ancestors didn't have any specific destination. They roamed wherever was favorable for their survival. Judging by the geographic and environmental conditions at the time, our African ancestors probably traveled along the coast where they could find food both on land and in the sea. As the population increased they moved to other parts of the world, including China. Why did the African migrants survive but not the original Chinese? Though ancient Africans survived the formidable difficulties and managed to travel to China thousands of years ago, why do geneticists claim they are ancestors of Chinese? What happened to the original primitive human inhabitants of China? Is it possible that modern Chinese people are descendents of these early native hominids or the result of interbreeding between them and the African migrants? Jin and his team originally took this possibility into consideration. After all, many ancient human fossils had been discovered in Asia, especially in China. Their shapes and timelines displayed continuity and the inheritance of traits. To allow for this possibility, Jin's team collected their samples from all over China to see if they could find a different mutation of M168. But they found nothing new. Their conclusion remained that the ancestor of all modern Chinese people was a pure-blooded African. How did the original human population of China disappear?
Regarding the question, what happened to the original hominid population of China, Jin Li pointed out that there is a 60,000 year gap in the human fossil record. All ancient human fossils are older than 100,000 years, while modern human fossils are all less than 40,000 years old (and mostly 10,000 to 30,000 years old). That means no human fossils from 50,000 to 100,000 years old, that might support the hypothesis of multi-regional evolution, have yet been found in China. Jin Li believes this gap is not accidental. During that 50,000 year period, the majority of biological species on the East Asian mainland became extinct.
That fossil gap corresponds to the Quaternary ice age, which killed off the majority of species, including indigenous humans, in East Asia, as well as other parts of the world. But in Africa, near the equator, where the temperature remained relatively high, ancient human beings were able to survive and reproduce. Kong Xinggong from the School of Geographical Sciences of Nanjing Normal University, said that during the ice age, the average temperature in the equatorial regions was only 1-2 ! lower than now, while closer to the poles, the temperature dropped dramatically.
This explains why equatorial Africans survived, while the ancient human populations from other parts of world disappeared. The Neanderthals became extinct in Europe about 20,000 years ago, at the height of the ice age there. After the ice age, Africans migrated from Southeast Asia into Chinese mainland, replaced ancient pre-glacial man there, and became the ancestors of the modern Chinese. Professor Jin Li sees the African origin of the Chinese people as a hard fact, but not everyone agrees. Some scientists say it is wrong to rely solely on genetics to establish the origins of modern humans.
Academician Wu Xinzhi from Institute of Vertebrate Paleontology and Paleoanthropology at the Chinese Academy of Sciences, believes that the ancient human population on the Chinese mainland did not die out, but evolved into modern Chinese. In other words, modern Chinese people have a direct lineal descent from the original hominid inhabitants. On what does Wu base his argument and can it stand up to scrutiny? The history of modern humans starts with late Homo sapiens.
Dr. Xing Song from the Institute of Vertebrate Paleontology and Paleoanthropology, CAS, says we must first define what we mean by the origin of modern man. It is a completely different concept from the origin of mankind. The latter refers to when and where the ancient apes evolved into people; while the origin of modern man refers to when and where people who look like modern humans originated. The academic view is that modern humans, the latest phase in the history of human evolution, i.e. late Homo sapiens, appeared in the period from around 50,000 to 10,000 years ago.
Except for some particular characteristics, late Homo sapiens are basically the same as today's humans. Their fossils are widely distributed not only in Asia, Africa, and Europe but also in Australia and the Americas. Remains of late Homo sapiens dating back to between 50,000 to 37,000 years ago have been found all over China. The finds include Hetao man in Erdos, Inner Mongolia; Liujiang Man, dating back 50,000 to 30,000 years, in Liujiang County, Guangxi; the Upper cave man, dating back 30,000 years, in Zhoukoudian, near Beijing; and Ziyang man dating back 10,000 years, in Ziyang City, Sichuan. Professor Jin Li maintains that late Homo sapiens from all over the world, including China, had common ancestors, that is, migrating Africans, who arrived in China 60,000 years ago. China has been continuously settled by humans since the earliest times
But despite the seemingly conclusive genetic evidence, Professor Wu Xinzhi insists the debate between "single-region evolution" and "multi-region evolution," is not settled. He maintains that Africa is not the only origin of modern humans, but that modern man evolved separately in several parts of world. He believes there is ample evidence that at least some of the ancestors of modern Chinese were native to the area.
From the 1920s on, archaeologists discovered large numbers of ancient human fossils in China. According to Professor Wu, different populations of ancient humans lived in overlapping periods. Yuanmou Man in Yunnan Province dates back 1,700,000 years, Shaanxi Lantian Man 1,150,000 to 600,000 years, Peking Man 500,000 to 200,000 years, Shandong Yiyuan man 400,000 years, Anhui Hexian 300,000 to 200,000 years and Guangdong Maba Man 100,000 years.
Ancient human fossils found in China
Homo erectus:
Yuanmou Man 1,700,000 years ago, in Yuanmou County of Yunnan Province
Lantian Man 1,150,000 to 600,000 years ago, in Lantian County of Shaanxi Province
No. 1 Nanjing Man 600,000 years ago, Tangshan of Nanjing
Peking Man 500,000 to 200,000 years ago, Zhoukoudian of Beijing
Yiyuan Man 400,000 years ago, Yiyuan of Shandong Province
Early Homo sapiens:
Dali Man 230,000 to 180,000 years ago, Dali of Shaanxi Province
Maba Man 200,000 to 160,000 years ago, Maba of Guangdong Province
Changyang Man 195,000 years ago, Changyang of Hubei Province
Late Homo sapiens Upper Cave Man 30,000 years ago, Zhoukoudian of Beijing
Liujiang Man 50,000 to 30,000 years ago, Liujiang County of Guangxi Province
The fossil record shows that in China there have always been different populations of ancient humans. Therefore, it remains possible that today's Chinese people are directly descended from them. But there is a major problem facing the proponents of the multi-regional thesis: in China fossils from different eras are rarely found in the same location. This implies the different populations were unrelated and casts doubt on the thesis of continuity of settlement.
Wu says this is because not all of the ancient human remains were fossilized and became available to later generations. Essentially he is saying there are haphazard gaps in the fossil record. Is Nanjing Man the ancestor of the modern Chinese? Xu Hankui, a researcher from the Nanjing Paleontology Institute, who discovered the fossil remains of Nanjing Man, also supports the hypothesis of multi-regional evolution. When fossilized skulls of Nanjing Man were discovered by peasants exploring an ancient lava cave, Nanjing Paleontology Institute sent several experts on a field trip. Xu was among them and participated in the study of the fossils.
Later, the Institute of Vertebrate Paleontology and Paleoanthropology showed that one of the skulls was of a 21 to 35-year-old women who lived 600,000 years ago and suffered from a bone disease called periostitis. She had many of the characteristics of Beijing Homo erectus, and genetic connections with other ancient Chinese human fossils. Another skull was from a male somewhere in the transitional phase between Homo erectus to Homo sapiens. There was gap of 100,000 years between the two skulls, and the finds showed evidence of continuous evolution of ancient Chinese human populations. Xu Hankui believes that the Nanjing Man finds are evidence of multi-regional evolution.
The puzzle of Chinese people's shovel-shaped front teeth: One of the puzzles that the out-of-Africa theory needs to account for is the prevalence of shovel-shaped front teeth among the modern Chinese population. Dr. Xing Song says the distinctively-shaped teeth are prevalent in the Mongoloid race in East Asia. Licking their inside front teeth, Chinese people will find that there's a dent in their upper teeth while the surfaces of the lower ones are even. From the inside, the upper teeth look like shovels. According to Xing, these peculiarly shaped teeth were inherited in a continuous line from early Chinese hominids. About 80 percent of Chinese have such upper front teeth in contrast to only 5 percent of Europeans and 10 percent of Africans. Xing says this is strong evidence of the continuity of human evolution in China. Moreover, hominid fossils in China share the same facial features: comparatively flat faces, a larger angle between the nose and the forehead, a flat nose bridge, rectangular eye sockets and forward-projecting cheekbones. All these features are absent in Africans.
Early Chinese lacked advanced stone technology seen in Africa. The stone artifacts unearthed in China also present difficulties for the out-of-Africa theory. In Palestine, archaeologists discovered stone artifacts from 100,000 years ago. These artifacts, very sophisticated and skillfully made, belong to the third phase of stone artifacts, much more advanced than the first and second phases. Palestine is an obvious route for African hominids to travel to the Eurasian Continent. If the geneticists are right, the African ancestors of the modern Chinese left Africa about 100,000 years ago, and passed through Palestine before reaching China some 60,000 years ago. Logically, the trekking Africans should have had the skills to make third phase stone artifacts when they arrived in China, and we would expect to find such artifacts.
But the fact is that the most basic stone artifacts, dating back 1.7 million years ago, were still in use on the Chinese mainland 30,000 years ago. About 98 percent of stone artifacts used by Chinese hominids belong to the "first phase." If migrating Africans were the ancestors of modern Chinese, why didn't they carry their advanced stone-working skills to China?
Huang Wanbo, a research fellow of the Institute of Vertebrate Paleontology and Paleoanthropology of Chinese Academy of Sciences, has been conducting paleoanthropological research for more than 20 years in the Three Gorges area. He says that just as the physical characteristics of East Asian hominid fossils can be traced back to a single origin, so can the artifacts of ancient East Asian cultures. For example, the "hand-axe" was one of the important African stone artifacts, dating back 1.7 million years. Most were made of obsidian formed by volcanic eruptions. In contrast, the ancient Chinese mostly used choppers and crushers made of quartz.
Gao Xing, another research fellow, echoed his colleague's opinion, saying that Chinese culture had developed continuously without interruption since remote antiquity and there was no sign that it had ever been replaced by foreign cultures. Chinese may be "hybrid" descendants of "natives" and African migrants. Wu doesn't rule out that Chinese people interbred with African or European migrants but maintains this was relatively rare.
There is evidence of genetic exchanges between ancient Chinese and Europeans and Southeast Asians. Unlike the rectangular eye sockets of most Chinese hominid fossils, the Maba skulls unearthed in south China's Guangdong Province had round orbits, which may have come from interbreeding with Europeans. Another example is the bulging occipital bone in skulls discovered in Guangxi. Similar skulls were also discovered in Sichuan and Yunnan. The characteristics are also typical of Europeans. Moreover, some ancient Chinese skulls also exhibit high nose bridges, which could come from either European or African ancestors.
Xu Hankui says the similarities between the skulls of Nanjing Man and European and African Homo erectus and Homo sapiens prove that hybridization took place during the evolution of the modern Chinese. Wu says hybridization became more frequent as human travels covered a wider area. Foreign genes gradually changed the original Chinese type. As a result some modern Chinese have rectangular eye sockets and some have round ones.
Papers anti-OOA favoring multiregionalism (I suspect the mandibular foramen is due to cold water/air selecting for a parallel in neandertal and European Hs, IOW no mixing of genes)
neandertal & AMH
Actually, I think 120ka Hs was thinly distributed along coasts and river valleys throughout the tropics from the East African Rift and coast, then 74ka Mt Toba exploded killing many around India, so from Papua some went to Malaya and split to west to India or east to China, while some from N Africa/Rift went east to Arabia/Iran/Caspian... tough call.
-
Interesting, grain seeds were cut with stone tools 105ka in Mozambique:
http://tech.groups.yahoo.com/group/AAT/message/55114
750ka Jordan Valley site shows use of waterside flora/fauna:
http://tech.groups.yahoo.com/group/AAT/message/55115
-
From Africa to India 100ka, from India to China 10ka
Scientists rejig human evolution, Indians ancestors of East Asians
Africa-India-China
Calcutta News.Net
Friday 11th December, 2009 (IANS)
The ancestors of the present-day populations of China, Japan and other east Asian countries had migrated from India, scientists from 10 countries including India said Friday after achieving a breakthrough in the study of the evolution of humans and their spread across the world. This large study establishes that ancient Indian population was a source of ancestors of Japanese, Chinese and all other East Asians... Samir Brahmachari, director general of the Council for Scientific and Industrial Research (CSIR) told IANS Friday. According to the study, people from India moved to southeast Asia and east Asia. 'They all have a common genetic origin. It shows that India represents a microcosm of Asia's genetic diversity,' Brahmachari, who was a key researcher in this study, later informed media persons here. Scientists said that earlier it was believed that several groups of people from Africa entered India, China, Japan and other eastern Asian regions separately.
'But this study now negates them all. There was only a single group of entry from southern Africa to India around 100,000 years ago. They entered India through land but in and around the coastal belt. They slowly spread to southern India and moved to south east and east Asian regions,' the CSIR chief added. He said these Indians and their genetic mutation variety slowly migrated to other parts of Asia. 'This will give a new meaning to human evolution theory and its spread.' The study, which traces the 'genetic origins of Asian population' was conducted by 90 scientists from 10 countries in over 30 scientific institutions. At least 10 scientists from three key Indian science research labs were part of the study.
It took five years for these top scientists to come up with these new findings which will pave the way for more historical, medical and anthropological studies. Congratulating Indian scientists and the 'path breaking study', Science and Technology Minister Prithviraj Chavan said: 'It has important implications, in furthering the understanding of migratory patterns in human history and for the study of genetics and diseases.'
It also has political ramifications, he noted. 'In spite of many political differences, these Asian nations worked together to produce such a study that has wide implication on the origin of people. The study suggest that there was a single initial entry into the continent of Asia, instead of multiple inflows,' Chavan added.
-
Taiwan not homeland of Austronesians?
"In addition, the topology of the maximum-likelihood population tree (Fig. 1)
seems to suggest that Taiwan aborigines may be derived from, rather than
ancestral to other Austronesian populations, because they occupy central, rather
than peripheral positions within the cluster of Austronesian speaking
populations. This observation seems to contradict a commonly cited Taiwan
"homeland" hypothesis of Austronesian populations. Given a nearly total lack of
prior autosomal data from Southeast Asian populations (9, 10), and conflicting
evidence based on mtDNA analyses, some of which questions the Taiwan homeland
story...
The scientists also reported a clear increase in genetic diversity from northern to southern latitudes. Their findings also suggest that there was one major inflow of human migration into Asia arising from Southeast Asia, rather than multiple inflows from both southern and northern routes as previously proposed. This indicates that Southeast Asia was the major geographic source of East Asian and North Asian populations.
(A figure illustrating the paper shows plausible routes of pre-historical migration of Asian human populations. According to the study, the PanAsia SNP Initiative, the most recent common ancestors of Asians arrived first in India and later, some of them migrated to Thailand, and South to the lands known today as Malaysia, Indonesia, and the Philippines. The first group of settlers must have gone very far south before they settled successfully. These included the Malay Negritos , Philippine Negritos , the East Indonesians, and early settlers of the Pacific Islands. Thereafter, one or several groups of people migrated North, mixed with previous settlers there and, finally, formed various populations we now refer to as Austronesian, Austro-Asiatic, Tai-Kadai, Hmong-Mien, and Altaic. The figure is titled, "Putative Pre-Historical Migration Routes of Asian Human Populations.")
http://www.eurekalert.org/pub_releases/2009-12/afst-gah120909.php
"…More than 90% of East Asian (EA) haplotypes could be found in either Southeast Asian (SEA) or Central-South Asian (CSA) populations and show clinal structure with haplotype diversity decreasing from south to north. Furthermore, 50% of EA haplotypes were found in SEA only and 5% were found in CSA only, indicating that SEA was a major geographic source of EA populations…"
"…The geographic source(s) contributing to EA populations have long been debated. One hypothesis
suggests that all SEA and EA populations derive primarily from a single initial migration,
which entered the continent along a southern, largely coastal route (19, 20). Another hypothesis
argues for at least two independent migrations into East Asia, first along a southern route, followed later by a series of migrations along a more northern route that served to bridge European and EA populations, but with little contribution to populations in Southeast Asia…"
"…the evidence from our autosomal data and the accompanying simulation studies (figs.
S29 and S30) point toward a history that unites the Negrito and non-Negrito populations of Southeast and East Asia via a single primary wave of entry of humans into the continent…"
India centre of Asian evolution?
NDTV Correspondant, Friday December 11, 2009, New Delhi
How did Asian populations evolve? Did they come from Europe, were they native to Asia? A new study that mapped human diversity across Asian nations reinforces an older controversial theory that after human beings first evolved in Africa, they possibly migrated to India via the land and sea routes. So out of Africa, India became the melting pot where humans evolved and then slowly spread all over Asia. This also means that after Africa some of the oldest living populations of humans can be found in India. Some of the tribes in the Andaman and Nicobar Islands the Jarawas, Onges and Great Andamanese are the closest relative mans ancestors.
-
Out of Africa to China: African Eve of Chinese
All modern humans are descended from a 200,000-year-old African woman. In 1987 the New Zealander Allan Charles Wilson and Rebecca Cann published a study of mitochondrial DNA that supported the "African Eve" theory that all human beings living today are descendents of a single woman who lived in Africa around 200,000 years ago. According to Wilson and Cann descendents of this "African Eve" migrated around the world and later evolved into the different varieties of modern humans. Since then more and more genetic evidence has accumulated, all supporting the view that modern humans, including Chinese people, originated from a single population in Africa. In 1998, Chinese scientist Chu Jiayou and his team analyzed the DNA microsatellites (also known as simple sequence repeats) of northern and southern Chinese, both those of Han and ethnic minorities. Chu concluded that the ancestors of the modern Chinese had migrated to China from Africa via South Asia. As the mutation rate of DNA microsatellites is high, it is not the best method available for researching ancient human migration and the evolution process. Su Bing and other scientists from the Kunming Institute of Zoology proposed an alternative approach using single nucleotide polymorphism (SNP) in the Y-chromosome (Y-SNP). This was the approach used by Prof. Jin Li and associate professor Li Hui.
DNA molecules point to a startling conclusion: Jin chose the Y-chromosome because it is relatively pure from a genetic perspective. Human beings have two sets of chromosomes, X and Y, inherited from our mothers and fathers respectively. The Y-chromosome comes from male and has a low mutation rate. It reflects how human genes are passed on from generation to generation more clearly than the X chromosome. As a result, geneticists see it as ideal material for the study of human origins. Jin and his team focused on three SNPs on the Y-chromosome M89, M130 and YAP. They are mutations of another mutated DNA molecule M168, which originated in Africa between 31,000 and 79,000 years ago.
"M168 originated only in East Africans. All people outside Africa and some Africans still have it. So it is the most direct evidence to prove that modern humans came from Africa." Jin wrote in his paper. How do scientists work out the age of a DNA component? How do scientists know M168 existed in ancient Africa? How do they work out exactly when it originated? Associate Professor Li Hui said that non-genic DNA sequences are used in molecular anthropology because genes possess many physiological functions. If a gene mutates, a person's health may be greatly affected. There are two fundamental features of the materials Jin and his team chose: they were non-genic and genetic haploid. Mitochondrial DNA and Y-chromosomes belong to this category. Most of the Y-chromosome consists of non-genic sequences. The team analyzed two types of mutation of the non-genic sequence. The first was SNP. This type of mutation is rare and stable. It will not repeat or change back to its original form. The structural relationships of all types of Y-chromosome all over the world are based on this feature. The other type of mutation was short tandem repeats (STR). These lengthen and shorten at a constant speed. Thus the origin of each type of Y chromosome can be dated by dividing the total number of mutations by the rate of mutation.
In other words analysis of SNP and SRT mutations show when the M168 mutation occurred. DNA from modern Chinese proves their African origins. Jin Li and his team randomly selected 9,988 Chinese males as samples. They found that all samples of M89, M130, and YAP led to only three mutations. 9,329 samples (93.4 percent) mutated into M89T0M130C and YAP-; 370 samples (3.7 percent) mutated into M89C0M130T and YAP-. 290 samples (2.9 percent) mutated into M89C0M130C and YAP+. No new mutation was found. The results coincided with findings in other parts of the world, that is, M168 displayed no new mutations in China. The result proved that Chinese people must have come from Africa, along with all other modern humans. But Jin Li's research also supported the African origin theory from another perspective, which was beyond their original expectations.
Tracing human migration routes using DNA: Besides trying to find evidence to prove one way or another whether Chinese people had an independent origin, Jin and his team wanted to study the genetic differences among people living in different parts of China by investigating the distribution frequency of the three ancient Y-chromosomes.
The molecular genetic structure of each ethnic group has its own particular characteristics. By analyzing the mutation process of M89, M130 and YAP, they figured out the distribution and migration routes of the different ethnic groups in China. For example, most samples that mutated into M89T, M130C and YAP- were from Han Chinese individuals. The other two types of mutation were more common in ethnic minorities.
Li Hui tested his own DNA to see where his ancestors came from. His Y-chromosome is type 01, which originated around Beibu Bay and the west of Hainan Province about 20,000 years ago. Type 01 then traveled to Guangdong, Taiwan and Fujian about 10,000 years ago and moved to the coastal areas of Jiangsu and Zhejiang 8,000 years ago. So Li's ancestors must have followed the same route.
Scientists use similar methods to tell how the original Africans migrated around the world. Li Shilin, a teacher at RCCASFU, says human ancestors didn't have any specific destination. They roamed wherever was favorable for their survival. Judging by the geographic and environmental conditions at the time, our African ancestors probably traveled along the coast where they could find food both on land and in the sea. As the population increased they moved to other parts of the world, including China. Why did the African migrants survive but not the original Chinese? Though ancient Africans survived the formidable difficulties and managed to travel to China thousands of years ago, why do geneticists claim they are ancestors of Chinese? What happened to the original primitive human inhabitants of China? Is it possible that modern Chinese people are descendents of these early native hominids or the result of interbreeding between them and the African migrants? Jin and his team originally took this possibility into consideration. After all, many ancient human fossils had been discovered in Asia, especially in China. Their shapes and timelines displayed continuity and the inheritance of traits. To allow for this possibility, Jin's team collected their samples from all over China to see if they could find a different mutation of M168. But they found nothing new. Their conclusion remained that the ancestor of all modern Chinese people was a pure-blooded African. How did the original human population of China disappear?
Regarding the question, what happened to the original hominid population of China, Jin Li pointed out that there is a 60,000 year gap in the human fossil record. All ancient human fossils are older than 100,000 years, while modern human fossils are all less than 40,000 years old (and mostly 10,000 to 30,000 years old). That means no human fossils from 50,000 to 100,000 years old, that might support the hypothesis of multi-regional evolution, have yet been found in China. Jin Li believes this gap is not accidental. During that 50,000 year period, the majority of biological species on the East Asian mainland became extinct.
That fossil gap corresponds to the Quaternary ice age, which killed off the majority of species, including indigenous humans, in East Asia, as well as other parts of the world. But in Africa, near the equator, where the temperature remained relatively high, ancient human beings were able to survive and reproduce. Kong Xinggong from the School of Geographical Sciences of Nanjing Normal University, said that during the ice age, the average temperature in the equatorial regions was only 1-2 ! lower than now, while closer to the poles, the temperature dropped dramatically.
This explains why equatorial Africans survived, while the ancient human populations from other parts of world disappeared. The Neanderthals became extinct in Europe about 20,000 years ago, at the height of the ice age there. After the ice age, Africans migrated from Southeast Asia into Chinese mainland, replaced ancient pre-glacial man there, and became the ancestors of the modern Chinese. Professor Jin Li sees the African origin of the Chinese people as a hard fact, but not everyone agrees. Some scientists say it is wrong to rely solely on genetics to establish the origins of modern humans.
Academician Wu Xinzhi from Institute of Vertebrate Paleontology and Paleoanthropology at the Chinese Academy of Sciences, believes that the ancient human population on the Chinese mainland did not die out, but evolved into modern Chinese. In other words, modern Chinese people have a direct lineal descent from the original hominid inhabitants. On what does Wu base his argument and can it stand up to scrutiny? The history of modern humans starts with late Homo sapiens.
Dr. Xing Song from the Institute of Vertebrate Paleontology and Paleoanthropology, CAS, says we must first define what we mean by the origin of modern man. It is a completely different concept from the origin of mankind. The latter refers to when and where the ancient apes evolved into people; while the origin of modern man refers to when and where people who look like modern humans originated. The academic view is that modern humans, the latest phase in the history of human evolution, i.e. late Homo sapiens, appeared in the period from around 50,000 to 10,000 years ago.
Except for some particular characteristics, late Homo sapiens are basically the same as today's humans. Their fossils are widely distributed not only in Asia, Africa, and Europe but also in Australia and the Americas. Remains of late Homo sapiens dating back to between 50,000 to 37,000 years ago have been found all over China. The finds include Hetao man in Erdos, Inner Mongolia; Liujiang Man, dating back 50,000 to 30,000 years, in Liujiang County, Guangxi; the Upper cave man, dating back 30,000 years, in Zhoukoudian, near Beijing; and Ziyang man dating back 10,000 years, in Ziyang City, Sichuan. Professor Jin Li maintains that late Homo sapiens from all over the world, including China, had common ancestors, that is, migrating Africans, who arrived in China 60,000 years ago. China has been continuously settled by humans since the earliest times
But despite the seemingly conclusive genetic evidence, Professor Wu Xinzhi insists the debate between "single-region evolution" and "multi-region evolution," is not settled. He maintains that Africa is not the only origin of modern humans, but that modern man evolved separately in several parts of world. He believes there is ample evidence that at least some of the ancestors of modern Chinese were native to the area.
From the 1920s on, archaeologists discovered large numbers of ancient human fossils in China. According to Professor Wu, different populations of ancient humans lived in overlapping periods. Yuanmou Man in Yunnan Province dates back 1,700,000 years, Shaanxi Lantian Man 1,150,000 to 600,000 years, Peking Man 500,000 to 200,000 years, Shandong Yiyuan man 400,000 years, Anhui Hexian 300,000 to 200,000 years and Guangdong Maba Man 100,000 years.
Ancient human fossils found in China
Homo erectus:
Yuanmou Man 1,700,000 years ago, in Yuanmou County of Yunnan Province
Lantian Man 1,150,000 to 600,000 years ago, in Lantian County of Shaanxi Province
No. 1 Nanjing Man 600,000 years ago, Tangshan of Nanjing
Peking Man 500,000 to 200,000 years ago, Zhoukoudian of Beijing
Yiyuan Man 400,000 years ago, Yiyuan of Shandong Province
Early Homo sapiens:
Dali Man 230,000 to 180,000 years ago, Dali of Shaanxi Province
Maba Man 200,000 to 160,000 years ago, Maba of Guangdong Province
Changyang Man 195,000 years ago, Changyang of Hubei Province
Late Homo sapiens Upper Cave Man 30,000 years ago, Zhoukoudian of Beijing
Liujiang Man 50,000 to 30,000 years ago, Liujiang County of Guangxi Province
The fossil record shows that in China there have always been different populations of ancient humans. Therefore, it remains possible that today's Chinese people are directly descended from them. But there is a major problem facing the proponents of the multi-regional thesis: in China fossils from different eras are rarely found in the same location. This implies the different populations were unrelated and casts doubt on the thesis of continuity of settlement.
Wu says this is because not all of the ancient human remains were fossilized and became available to later generations. Essentially he is saying there are haphazard gaps in the fossil record. Is Nanjing Man the ancestor of the modern Chinese? Xu Hankui, a researcher from the Nanjing Paleontology Institute, who discovered the fossil remains of Nanjing Man, also supports the hypothesis of multi-regional evolution. When fossilized skulls of Nanjing Man were discovered by peasants exploring an ancient lava cave, Nanjing Paleontology Institute sent several experts on a field trip. Xu was among them and participated in the study of the fossils.
Later, the Institute of Vertebrate Paleontology and Paleoanthropology showed that one of the skulls was of a 21 to 35-year-old women who lived 600,000 years ago and suffered from a bone disease called periostitis. She had many of the characteristics of Beijing Homo erectus, and genetic connections with other ancient Chinese human fossils. Another skull was from a male somewhere in the transitional phase between Homo erectus to Homo sapiens. There was gap of 100,000 years between the two skulls, and the finds showed evidence of continuous evolution of ancient Chinese human populations. Xu Hankui believes that the Nanjing Man finds are evidence of multi-regional evolution.
The puzzle of Chinese people's shovel-shaped front teeth: One of the puzzles that the out-of-Africa theory needs to account for is the prevalence of shovel-shaped front teeth among the modern Chinese population. Dr. Xing Song says the distinctively-shaped teeth are prevalent in the Mongoloid race in East Asia. Licking their inside front teeth, Chinese people will find that there's a dent in their upper teeth while the surfaces of the lower ones are even. From the inside, the upper teeth look like shovels. According to Xing, these peculiarly shaped teeth were inherited in a continuous line from early Chinese hominids. About 80 percent of Chinese have such upper front teeth in contrast to only 5 percent of Europeans and 10 percent of Africans. Xing says this is strong evidence of the continuity of human evolution in China. Moreover, hominid fossils in China share the same facial features: comparatively flat faces, a larger angle between the nose and the forehead, a flat nose bridge, rectangular eye sockets and forward-projecting cheekbones. All these features are absent in Africans.
Early Chinese lacked advanced stone technology seen in Africa. The stone artifacts unearthed in China also present difficulties for the out-of-Africa theory. In Palestine, archaeologists discovered stone artifacts from 100,000 years ago. These artifacts, very sophisticated and skillfully made, belong to the third phase of stone artifacts, much more advanced than the first and second phases. Palestine is an obvious route for African hominids to travel to the Eurasian Continent. If the geneticists are right, the African ancestors of the modern Chinese left Africa about 100,000 years ago, and passed through Palestine before reaching China some 60,000 years ago. Logically, the trekking Africans should have had the skills to make third phase stone artifacts when they arrived in China, and we would expect to find such artifacts.
But the fact is that the most basic stone artifacts, dating back 1.7 million years ago, were still in use on the Chinese mainland 30,000 years ago. About 98 percent of stone artifacts used by Chinese hominids belong to the "first phase." If migrating Africans were the ancestors of modern Chinese, why didn't they carry their advanced stone-working skills to China?
Huang Wanbo, a research fellow of the Institute of Vertebrate Paleontology and Paleoanthropology of Chinese Academy of Sciences, has been conducting paleoanthropological research for more than 20 years in the Three Gorges area. He says that just as the physical characteristics of East Asian hominid fossils can be traced back to a single origin, so can the artifacts of ancient East Asian cultures. For example, the "hand-axe" was one of the important African stone artifacts, dating back 1.7 million years. Most were made of obsidian formed by volcanic eruptions. In contrast, the ancient Chinese mostly used choppers and crushers made of quartz.
Gao Xing, another research fellow, echoed his colleague's opinion, saying that Chinese culture had developed continuously without interruption since remote antiquity and there was no sign that it had ever been replaced by foreign cultures. Chinese may be "hybrid" descendants of "natives" and African migrants. Wu doesn't rule out that Chinese people interbred with African or European migrants but maintains this was relatively rare.
There is evidence of genetic exchanges between ancient Chinese and Europeans and Southeast Asians. Unlike the rectangular eye sockets of most Chinese hominid fossils, the Maba skulls unearthed in south China's Guangdong Province had round orbits, which may have come from interbreeding with Europeans. Another example is the bulging occipital bone in skulls discovered in Guangxi. Similar skulls were also discovered in Sichuan and Yunnan. The characteristics are also typical of Europeans. Moreover, some ancient Chinese skulls also exhibit high nose bridges, which could come from either European or African ancestors.
Xu Hankui says the similarities between the skulls of Nanjing Man and European and African Homo erectus and Homo sapiens prove that hybridization took place during the evolution of the modern Chinese. Wu says hybridization became more frequent as human travels covered a wider area. Foreign genes gradually changed the original Chinese type. As a result some modern Chinese have rectangular eye sockets and some have round ones.
Papers anti-OOA favoring multiregionalism (I suspect the mandibular foramen is due to cold water/air selecting for a parallel in neandertal and European Hs, IOW no mixing of genes)
neandertal & AMH
Tuesday, December 8, 2009
Flower-fruit plants => Flying fauna! CO2, O2, N2
Green plants can't uptake carbon from soil, because they use water to move nutrients, water + carbon = carbonic acid (eats limestone -> caves). Soil fungi do decompose carbs, as do animals, and exude CO2. Plant leaves "breathe" O2 just like animals and fungi. Plant leaves "eat" CO2, using solar energy to decompose it into O2 & C, the C is then combined with H et al to make carbs for plant tissue. Plants (grasses) require wind to reduce stratification of gases (gas stratification starves them of C or chokes them of O2), tropical rainforests need mobile animals not only for fruit dissemination but also gas mixing (flying insects/fruit bats/fruit birds), this is the major advantage of angiosperm flora over non-fruiting gymnosperms (seeded but non-fruiting conifers) and the reason that flowering plants and symbiotic fauna "won" the competitive war against cycads, conifers, ferns, etc. Biological textbooks say little about gas stratification prevention, but it is critical in closed-canopy ecosystems (same reason that sealife comes in both mobile jetsam (tail/fin) & immobile photosynthetic flotsam). [my comment@]
flowers + fruit induce faunal flight to mix gas
-
flower origin
-
ancient scorpionflies pollinating gymnosperms?
ResearchBlogging.org
"The first flowering plants evolved more than a hundred million years ago, while dinosaurs were still on the scene. Since then, they’ve come to dominate the world, largely outcompeting the plants that were there before, such as conifers, cycads, and ginkgoes...The reason for showy flowers is to attract pollinators, most commonly insects. Today, the majority of flowering plants use insects to carry their pollen, whereas most gymnosperms (the older group of plants, including conifers) are pollinated by the wind. Insects have one clear advantage over the wind: they can track down another flower of the same species...From insect fossils, it looks like there were pollinators (scorpionflies) around in the Jurassic, which had evolved together with the gymnosperms that were around at the time...some fossil gymnosperms weren't well adapted for wind pollination."
http://takluyver.wordpress.com/2009/12/08/carbon-dioxide-and-nitrogen-not-such-a-double-whammy/
"Nitrogen makes up nearly 80% of the atmosphere, but pure nitrogen (aka N2) isn’t very easy to get at. What counts is ‘reactive nitrogen’, especially dissolved nitrate (NO3-) and ammonia (NH4+). Plants can readily take this up and use it, helping them to grow faster (NPK fert). In fact, over half of the reactive nitrogen being made each year now comes from human activities.
Ecologists know quite well that adding nitrogen often leads to fewer species living together. And a recent experiment neatly showed why that might be: when plants’ roots are battling it out for nutrients (like nitrogen), it’s a relatively fair fight. But add nitrogen, and the fight moves above the ground, for the light plants need to grow. Here, bigger plants can quickly shade out smaller ones and kill (some of) them off... carbon dioxide and nitrogen have different effects on plants, and they seem to balance out to some extent. Although the effect of light wasn’t clear cut in this experiment, I think it might also be important that higher carbon dioxide lets plants grow in deeper shade."
-
leaf veins
http://ecographica.blogspot.com/2009/12/evolution-is-in-veins-of-our-captors.html
"...primitive ancestors of the tyrannical angiosperms underwent adaptation to feed on the then abundant atmospheric carbon dioxide. Through undertaking a process known as photosynthesis, some early plant-forms gained reproductive advantage and quickly out-competed their rivals. In time, their numbers became so great that oxygen – a byproduct of photosynthesis - accumulated in the biosphere to such extent that it triggered a catastrophic transition to an oxygenated planet. In hindsight, this rapid transition, called the ‘Great Oxygenation Event,’ can be viewed as a first step in the angiosperms’ selfish remaking of the Earth, and as foreshadowing the eventual enslavement of all humankind.
Initially, constrained anatomy affectively limited the plants’ ability to channel the xylem tissues required for harnessing the sun’s rays. Xylem tissues are essential to photosynthesis because it is their job to convey water and nutrients throughout the plant. Early plants lacked sufficient internal structure and architecture to serve as pathways for xylem transport; this physically restricted the amount of energy that could be generated through photosynthesis. In other words, because of a lack of adequate venation, the radiation of angiosperms was kept in-check. However, this all changed during the Cretaceous Period.
Over the course of evolutionary history, natural selection tinkered at the physiology of the angiosperms, incrementally improving their clumsy and inefficient application of photosynthesis until eventually, about 120,000,000 years ago, the density of the angiosperms’ veins dramatically increased by 300-400%. The upsurge in venation meant that the plants’ xylem tissues more frequently made contact with individual plant cells; this pushed the capacity of the angiosperms’ energetic processes far beyond what they could achieve previously. Newly acquired energy surpluses were promptly invested in reproduction and as a result angiosperm populations exploded the world over."
Marine CO2 effects on shellfish, crustaceans, calcific algae:
crabs & CO2
(compare to green plants in soil which can't absorb carbonic acid through roots, so must consume CO2 in air via photosynthesis.)
eco-web-tet: ants, fungi, bacteria, plant in 4 way symbiotic relationship
plants & ants
Game theory: bacteria and human in decision making in stress
http://www.eurekalert.org/pub_releases/2009-12/uoc--bpn121109.php
flowers + fruit induce faunal flight to mix gas
-
flower origin
-
ancient scorpionflies pollinating gymnosperms?
ResearchBlogging.org
"The first flowering plants evolved more than a hundred million years ago, while dinosaurs were still on the scene. Since then, they’ve come to dominate the world, largely outcompeting the plants that were there before, such as conifers, cycads, and ginkgoes...The reason for showy flowers is to attract pollinators, most commonly insects. Today, the majority of flowering plants use insects to carry their pollen, whereas most gymnosperms (the older group of plants, including conifers) are pollinated by the wind. Insects have one clear advantage over the wind: they can track down another flower of the same species...From insect fossils, it looks like there were pollinators (scorpionflies) around in the Jurassic, which had evolved together with the gymnosperms that were around at the time...some fossil gymnosperms weren't well adapted for wind pollination."
http://takluyver.wordpress.com/2009/12/08/carbon-dioxide-and-nitrogen-not-such-a-double-whammy/
"Nitrogen makes up nearly 80% of the atmosphere, but pure nitrogen (aka N2) isn’t very easy to get at. What counts is ‘reactive nitrogen’, especially dissolved nitrate (NO3-) and ammonia (NH4+). Plants can readily take this up and use it, helping them to grow faster (NPK fert). In fact, over half of the reactive nitrogen being made each year now comes from human activities.
Ecologists know quite well that adding nitrogen often leads to fewer species living together. And a recent experiment neatly showed why that might be: when plants’ roots are battling it out for nutrients (like nitrogen), it’s a relatively fair fight. But add nitrogen, and the fight moves above the ground, for the light plants need to grow. Here, bigger plants can quickly shade out smaller ones and kill (some of) them off... carbon dioxide and nitrogen have different effects on plants, and they seem to balance out to some extent. Although the effect of light wasn’t clear cut in this experiment, I think it might also be important that higher carbon dioxide lets plants grow in deeper shade."
-
leaf veins
http://ecographica.blogspot.com/2009/12/evolution-is-in-veins-of-our-captors.html
"...primitive ancestors of the tyrannical angiosperms underwent adaptation to feed on the then abundant atmospheric carbon dioxide. Through undertaking a process known as photosynthesis, some early plant-forms gained reproductive advantage and quickly out-competed their rivals. In time, their numbers became so great that oxygen – a byproduct of photosynthesis - accumulated in the biosphere to such extent that it triggered a catastrophic transition to an oxygenated planet. In hindsight, this rapid transition, called the ‘Great Oxygenation Event,’ can be viewed as a first step in the angiosperms’ selfish remaking of the Earth, and as foreshadowing the eventual enslavement of all humankind.
Initially, constrained anatomy affectively limited the plants’ ability to channel the xylem tissues required for harnessing the sun’s rays. Xylem tissues are essential to photosynthesis because it is their job to convey water and nutrients throughout the plant. Early plants lacked sufficient internal structure and architecture to serve as pathways for xylem transport; this physically restricted the amount of energy that could be generated through photosynthesis. In other words, because of a lack of adequate venation, the radiation of angiosperms was kept in-check. However, this all changed during the Cretaceous Period.
Over the course of evolutionary history, natural selection tinkered at the physiology of the angiosperms, incrementally improving their clumsy and inefficient application of photosynthesis until eventually, about 120,000,000 years ago, the density of the angiosperms’ veins dramatically increased by 300-400%. The upsurge in venation meant that the plants’ xylem tissues more frequently made contact with individual plant cells; this pushed the capacity of the angiosperms’ energetic processes far beyond what they could achieve previously. Newly acquired energy surpluses were promptly invested in reproduction and as a result angiosperm populations exploded the world over."
Marine CO2 effects on shellfish, crustaceans, calcific algae:
crabs & CO2
(compare to green plants in soil which can't absorb carbonic acid through roots, so must consume CO2 in air via photosynthesis.)
eco-web-tet: ants, fungi, bacteria, plant in 4 way symbiotic relationship
plants & ants
Game theory: bacteria and human in decision making in stress
http://www.eurekalert.org/pub_releases/2009-12/uoc--bpn121109.php
Friday, December 4, 2009
34ma migrations
Cavies and new world monkeys emigrated from Africa to South America (via antarctica?) 34ma.
cavies
Cavioids and New World Monkeys migrated northwards as Antarctica froze 34ma
http://tech.groups.yahoo.com/group/AAT/message/50250
http://tech.groups.yahoo.com/group/AAT/message/50350
African Rift formed 34ma
http://tech.groups.yahoo.com/group/AAT/message/50253
Pinwheeling Pangea
http://tech.groups.yahoo.com/group/AAT/message/50257
http://tech.grou
ps.yahoo.com/group/AAT/message/50380
http://adsabs.harvard.edu/abs/2007AGUFM.U21E..01C
Cosmic impacts (oceanic?) on Earth and Moon 34ma
(Note that Australia separated from Antarctica 64ma, just after the Yucatan cosmic impact, deccan traps and C/K dino extinction of ~65ma) Aust. marsupials dispersed from So. America to Australia via Antarctca during late Cretaceous–early Paleocene.
La Meseta Fauna from Patagonia before early late Paleocene, other taxa arrived in early Eocene. http://www.springerlink.com/content/h5r16469kqr06560/
Fossil Land Mammal from Antarctica
MICHAEL O. WOODBURNE 1 and WILLIAM J. ZINSMEISTER 2
1 Department of Earth Sciences, University of California, Riverside 92521
2 Institute of Polar Studies and Department of Geology, Ohio State University, Columbus 43210
A fossil land mammal, apparently the first found in Antarctica, belongs to the extinct marsupial family Polydolopidae. The fossils were recovered from rocks about 40 million years old on Seymour Island, in the northern Antarctic Peninsula. The newly discovered marsupials support theories that predicted their former presence in Antarctica and strengthen proposals that Australian marsupials perhaps originated from South American species that dispersed across Antarctica when Australia still was attached to it, prior to 56 million years ago.
-
A Bizarre New Family of Marsupialia (Incertae sedis) from the Early Pliocene of Northeastern Australia: Implications for the Phylogeny of Bunodont Marsupials
We consider the distributions of a number of dental characters in bunodont marsupials and argue that no North American Late Cretaceous taxa can be convincingly referred to the order Polydolopimorphia. Thus, polydolopimorphians continue to be known only from the Cenozoic of Gondwana, with no fossil evidence that their initial divergences occurred in North America
-
These marsupials went from S America to Antarctica, some continued on to Australia.
Did monkeys and cavies go from Africa to Antarctica to S America? The timing data does not seem to indicate that this had happened. More likely both had rafted across the narrow but widening straits which eventually became the Atlantic Ocean. Currents may have brought vegetative rafts from W Africa westward to approximately Bolivia.
-
Today Antarctica is compressed gravitationally by millions of tons of glacial ice, pushing the former coastlines far below todays' sea level (highly susceptible to constant erosion from the antarctic circumpolar current), leaving only former highlands and mountain ranges. Fossils from 34ma monkeys and cavioids from the former rainforests there aren't accessible except at rare uplifted areas such as offshore isles, and south Argentina.
-
http://www.noc.soton.ac.uk/soes/staff/acng/SOFINE/SOFINE.html
The SOFINE project studies the 'frictional' processes that slow down the strongest current on Earth (the Antarctic Circumpolar Current, ACC) and drive the extension of the ocean's overturning circulation across the Southern Ocean. The experiment focuses on a major ACC meander (around the northern Kerguelen Plateau, southern Indian Ocean), which features as an area of intensified 'friction' and cross-ACC flow in most present theories and models of the Southern Ocean circulation.
-
http://www.ga.gov.au/oceans/sa_Kergln.jsp
Geological sampling and scientific drilling shows that it was emergent or under shallow water for up to 40 million years of its history. Wood fragments and coal found in Late Cretaceous sediments indicate that the plateau may have been covered with forests.
-
http://www.genetics.wayne.edu/lgross/Problems.html
among eutherian or placental mammals, the ceboids have one of the oldest histories in South America with 26-27 million year old fossils of the primitive ceboid Branisella (3) documenting that ceboids were already established in South America during the Oligocene. Among extant eutherians, only caviomorph rodents and edentates have older documented histories in South America, the former now being represented by a 34 million year old Eocene fossil (4,5) and the latter by early Cenzoic Paleocene fossils (6)
Branisella: oldest NWM fossil, from Bolivia: As a whole, the dentition of Branisella is very similar to that of Proteopithecus from the Late Eocene of Fayum, Egypt, except in the lower canine morphology, suggesting a close phyletic relationship between them.
New fossil platyrrhines from the Pinturas Formation, southern Argentina
John G. Fleagle
Early Miocene coastal Patagonia: Primates
Two new fossil vertebrate localities are described from the Santa Cruz Formation (late early – early middle Miocene) of coastal Patagonia. They are noteworthy because they are the lowest stratigraphically of any precisely recorded in coastal Santa Cruz Province and they contain a rich fauna including many partially articulated skeletons undisturbed by collecting. Thus, they offer the potential for taphonomic analysis and paleocommunity reconstruction. The latter is particularly intriguing because the fauna document the Miocene Climatic Optimum at >51° South latitude. Together with several previously documented sites in this region, it offers a potential window into the nature of mammalian communities farther south than any other in the world during this time and documents the farthest south distribution of primates.
-
Radiometric dates indicate that the fossil mammals (including platyrrhine primates) occurring in the lower and middle parts of the formation may range in age from about 16·6 to younger than 13·3 Ma (million years ago) (Santacrucian and, almost certainly, Friasian land-mammal ages). This age range is somewhat younger than previous estimates, and suggests that the Pinturas faunas correlate broadly with those from the type Santa Cruz Formation http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6WJS-4HCKFGH-6&_user=10&_coverDate=03%2F31%2F1990&_rdoc=1&_fmt=high&_orig=search&_sort=d&_docanchor=&view=c&_searchStrId=1258475485&_rerunOrigin=google&_acct=C000050221&_version=1&_urlVersion=0&_userid=10&md5=844d12d7aeedf097b12b5de1b5329587
-
Chronology of Cenozoic primate localities in South America
Journal of Human Evolution, Volume 19, Issues 1-2, February-March 1990, Pages 7-21
Bruce J. MacFadden
The available fossil record indicates that primates have occurred in South America since the middle Tertiary. The oldest known primate-bearing locality, Salla, Bolivia, of Deseadan age, was previously thought to be about 35 myr old, or early Oligocene age. However, 12 radioisotopic dates from Salla using40K-40Ar and fission-track methods and magnetostratigraphic correlations indicate a late Oligocene age for this site. The exact level that produced the earliest-known South American primate,Branisella, lies just above a tuffaceous zone that yielded dates of 26·4 ± 1·0 and 25·1 ± 0·7 Ma. The revision of the “primate datum” in Bolivia from early to late Oligocene has ramifications for: (1) the calibration of other, younger primate-bearing localities in South America; and (2) biogeographic hypotheses concerning primate origins in light of plate tectonics. The other known Tertiary primate localities in South America are of Colhuehuapian (ca. 18–19 Ma). Santacrucian (ca. 15–18 Ma) and possible Friasian (ca. 14–15 Ma) ages. There is a major gap of some 14 myr that exists between these primate occurrences of middle Miocene age and the next younger localities, which are all late Pleistocene.
"But some lemurs, oddly enough, have only two nipples, and they're located over the pectoral muscles where we have them, but where most other mammals don't."
Which ones? If only lemurs with enlarged air sacs have one pair of pectoral nipples, that would indicate upright aquatic foraging/floating as in gorillas and apiths (sea cows), parallel convergence.
Anthropoidea: (monkeys) subset of Haplorhines have only two actual breasts, pectoral mammae which are unlike those of other mammals. And unlike lemurs, most monkeys have completely lost the ability to move their ears. Monkeys also lack the specialized sensory whiskers and the wet nose that lemurs and so many "lesser" animals have, and lost the ability to synthesize either vitamin D3 or vitamin C.
cavies
Cavioids and New World Monkeys migrated northwards as Antarctica froze 34ma
http://tech.groups.yahoo.com/group/AAT/message/50250
http://tech.groups.yahoo.com/group/AAT/message/50350
African Rift formed 34ma
http://tech.groups.yahoo.com/group/AAT/message/50253
Pinwheeling Pangea
http://tech.groups.yahoo.com/group/AAT/message/50257
http://tech.grou
ps.yahoo.com/group/AAT/message/50380
http://adsabs.harvard.edu/abs/2007AGUFM.U21E..01C
Cosmic impacts (oceanic?) on Earth and Moon 34ma
(Note that Australia separated from Antarctica 64ma, just after the Yucatan cosmic impact, deccan traps and C/K dino extinction of ~65ma) Aust. marsupials dispersed from So. America to Australia via Antarctca during late Cretaceous–early Paleocene.
La Meseta Fauna from Patagonia before early late Paleocene, other taxa arrived in early Eocene. http://www.springerlink.com/content/h5r16469kqr06560/
Fossil Land Mammal from Antarctica
MICHAEL O. WOODBURNE 1 and WILLIAM J. ZINSMEISTER 2
1 Department of Earth Sciences, University of California, Riverside 92521
2 Institute of Polar Studies and Department of Geology, Ohio State University, Columbus 43210
A fossil land mammal, apparently the first found in Antarctica, belongs to the extinct marsupial family Polydolopidae. The fossils were recovered from rocks about 40 million years old on Seymour Island, in the northern Antarctic Peninsula. The newly discovered marsupials support theories that predicted their former presence in Antarctica and strengthen proposals that Australian marsupials perhaps originated from South American species that dispersed across Antarctica when Australia still was attached to it, prior to 56 million years ago.
-
A Bizarre New Family of Marsupialia (Incertae sedis) from the Early Pliocene of Northeastern Australia: Implications for the Phylogeny of Bunodont Marsupials
We consider the distributions of a number of dental characters in bunodont marsupials and argue that no North American Late Cretaceous taxa can be convincingly referred to the order Polydolopimorphia. Thus, polydolopimorphians continue to be known only from the Cenozoic of Gondwana, with no fossil evidence that their initial divergences occurred in North America
-
These marsupials went from S America to Antarctica, some continued on to Australia.
Did monkeys and cavies go from Africa to Antarctica to S America? The timing data does not seem to indicate that this had happened. More likely both had rafted across the narrow but widening straits which eventually became the Atlantic Ocean. Currents may have brought vegetative rafts from W Africa westward to approximately Bolivia.
-
Today Antarctica is compressed gravitationally by millions of tons of glacial ice, pushing the former coastlines far below todays' sea level (highly susceptible to constant erosion from the antarctic circumpolar current), leaving only former highlands and mountain ranges. Fossils from 34ma monkeys and cavioids from the former rainforests there aren't accessible except at rare uplifted areas such as offshore isles, and south Argentina.
-
http://www.noc.soton.ac.uk/soes/staff/acng/SOFINE/SOFINE.html
The SOFINE project studies the 'frictional' processes that slow down the strongest current on Earth (the Antarctic Circumpolar Current, ACC) and drive the extension of the ocean's overturning circulation across the Southern Ocean. The experiment focuses on a major ACC meander (around the northern Kerguelen Plateau, southern Indian Ocean), which features as an area of intensified 'friction' and cross-ACC flow in most present theories and models of the Southern Ocean circulation.
-
http://www.ga.gov.au/oceans/sa_Kergln.jsp
Geological sampling and scientific drilling shows that it was emergent or under shallow water for up to 40 million years of its history. Wood fragments and coal found in Late Cretaceous sediments indicate that the plateau may have been covered with forests.
-
http://www.genetics.wayne.edu/lgross/Problems.html
among eutherian or placental mammals, the ceboids have one of the oldest histories in South America with 26-27 million year old fossils of the primitive ceboid Branisella (3) documenting that ceboids were already established in South America during the Oligocene. Among extant eutherians, only caviomorph rodents and edentates have older documented histories in South America, the former now being represented by a 34 million year old Eocene fossil (4,5) and the latter by early Cenzoic Paleocene fossils (6)
Branisella: oldest NWM fossil, from Bolivia: As a whole, the dentition of Branisella is very similar to that of Proteopithecus from the Late Eocene of Fayum, Egypt, except in the lower canine morphology, suggesting a close phyletic relationship between them.
New fossil platyrrhines from the Pinturas Formation, southern Argentina
John G. Fleagle
Early Miocene coastal Patagonia: Primates
Two new fossil vertebrate localities are described from the Santa Cruz Formation (late early – early middle Miocene) of coastal Patagonia. They are noteworthy because they are the lowest stratigraphically of any precisely recorded in coastal Santa Cruz Province and they contain a rich fauna including many partially articulated skeletons undisturbed by collecting. Thus, they offer the potential for taphonomic analysis and paleocommunity reconstruction. The latter is particularly intriguing because the fauna document the Miocene Climatic Optimum at >51° South latitude. Together with several previously documented sites in this region, it offers a potential window into the nature of mammalian communities farther south than any other in the world during this time and documents the farthest south distribution of primates.
-
Radiometric dates indicate that the fossil mammals (including platyrrhine primates) occurring in the lower and middle parts of the formation may range in age from about 16·6 to younger than 13·3 Ma (million years ago) (Santacrucian and, almost certainly, Friasian land-mammal ages). This age range is somewhat younger than previous estimates, and suggests that the Pinturas faunas correlate broadly with those from the type Santa Cruz Formation http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6WJS-4HCKFGH-6&_user=10&_coverDate=03%2F31%2F1990&_rdoc=1&_fmt=high&_orig=search&_sort=d&_docanchor=&view=c&_searchStrId=1258475485&_rerunOrigin=google&_acct=C000050221&_version=1&_urlVersion=0&_userid=10&md5=844d12d7aeedf097b12b5de1b5329587
-
Chronology of Cenozoic primate localities in South America
Journal of Human Evolution, Volume 19, Issues 1-2, February-March 1990, Pages 7-21
Bruce J. MacFadden
The available fossil record indicates that primates have occurred in South America since the middle Tertiary. The oldest known primate-bearing locality, Salla, Bolivia, of Deseadan age, was previously thought to be about 35 myr old, or early Oligocene age. However, 12 radioisotopic dates from Salla using40K-40Ar and fission-track methods and magnetostratigraphic correlations indicate a late Oligocene age for this site. The exact level that produced the earliest-known South American primate,Branisella, lies just above a tuffaceous zone that yielded dates of 26·4 ± 1·0 and 25·1 ± 0·7 Ma. The revision of the “primate datum” in Bolivia from early to late Oligocene has ramifications for: (1) the calibration of other, younger primate-bearing localities in South America; and (2) biogeographic hypotheses concerning primate origins in light of plate tectonics. The other known Tertiary primate localities in South America are of Colhuehuapian (ca. 18–19 Ma). Santacrucian (ca. 15–18 Ma) and possible Friasian (ca. 14–15 Ma) ages. There is a major gap of some 14 myr that exists between these primate occurrences of middle Miocene age and the next younger localities, which are all late Pleistocene.
"But some lemurs, oddly enough, have only two nipples, and they're located over the pectoral muscles where we have them, but where most other mammals don't."
Which ones? If only lemurs with enlarged air sacs have one pair of pectoral nipples, that would indicate upright aquatic foraging/floating as in gorillas and apiths (sea cows), parallel convergence.
Anthropoidea: (monkeys) subset of Haplorhines have only two actual breasts, pectoral mammae which are unlike those of other mammals. And unlike lemurs, most monkeys have completely lost the ability to move their ears. Monkeys also lack the specialized sensory whiskers and the wet nose that lemurs and so many "lesser" animals have, and lost the ability to synthesize either vitamin D3 or vitamin C.
Subscribe to:
Posts (Atom)