Sunday, April 11, 2010

Stingrays, mollusks, humans in African Rift Valley 1.5ma

First, mangrove, mollusk econiche evolution via tectonic plate rift activity at Tethys shoreline, why SE Asian/west Pacific mangroves more diverse than Africa or So. America mangroves (Ellison):

African Rift, Lake Turkana - Ileret footprints in mud 1.5ma, shellfish harvesting

Apiths may have dug/finger-raked and consumed floating vegetation, shallow-shore tubers and shallow benthic invertebrates. But only genus Homo submerged fully while foraging, losing the laryngeal air sac and developing oral breathing and flatter hands and longer feet with short toes.

site habitat

"In 1984, the most complete hominin skeleton to date, KNM-WT 15000, was discovered eroding from a hillside at NK III. The specimen, which retained the skull and almost entire postcranial skeleton, belonged to a juvenile male Homo erectus/ergaster. Nicknamed the “Turkana Boy,” the specimen was determined to be 1.5 ma.

NK III site: Turkana Boy and fossil taxa include the freshwater stingray, Dasyatis Africana; the catfish, Synodontis; the extinct pig, Metrodiocherus; two extinct species of hippopotamus, Hippopotamus gorgops and H. aethiopicus; chelonian carapaces (turtle shells); some avian limb bones and phalanges; two species of bovid; sponge spicules; several species of ostracod (a crustacean); cichlids (a family of perciform fish); cyprinids (carps and minnows); and several varanids (monitor lizards). The paleoenvironment of the Nariokotome region during the time of the Turkana Boy has been reconstructed as a temporary marshland formed by the annual flooding of the Omo River with interspersed grassland and patches of woodland. One or more lakes were probably present as well."
anthro site history
Archaic Humans: Beavers & cleavers, sea waters & sea otters

Bilzingsleben, Germany, 325,000 years ago, microlith, pebble tools
Hoxne, England, 325,000 years ago - handaxes, extinct beaver, otter
Furze Platt, England, 325,000 years ago - large pointed handaxes, cleavers
Tan Tan, Morocco, 325,000 years ago - Mid Acheulian tools, female figurine
Beavers modify their habitat like humans do: Logging, Damming, Lodging
beavers arrested


A waterway linked the East African Rift Valley with the Indian Ocean 1.9ma, freshwater stingrays evolved there between 1.9 and 1.3ma after a marine incursion, the H erectus/ergaster skeleton Turkana boy was found there at waterside region. Probably Homo species, stingrays and 3 species of mollusks moved from Indian Ocean estuaries into the Rift valley lakes then, during a wet/high sea level period. The same time, Dmanisi, Georgia had H erectus/georgicus occupants living between the Caspian and Black seas. Tectonic plate collisions have uplifted the area since 1.8ma.

This site of early hominins is in Republic of Georgia, south of the Caucasus Mountains, east of the Black Sea, west of the Caspian Sea, on a wooded promontory surrounded by steep cliffs and water on three sides, that might have provided an ideal place to drive and ambush game.

Did they speak? Most likely they clicked & hummed/sang:
Meyer and his colleagues — David Lordkipanidze and Abesalom Vekua, both of the Georgian State Museum in Tbilisi — compared the size, shape, and volume of the Dmanisi vertebrae with more than 2 200 corresponding bones from people, chimpanzees, and gorillas.

"The Dmanisi spinal column falls within the human range and would have comfortably accommodated a modern human spinal cord," Meyer says.

Moreover, the fossil vertebrae would have provided ample structural support for the respiratory muscles needed to articulate words, he asserts. Although it's impossible to confirm that our prehistoric ancestors talked, Meyer notes, H. erectus at Dmanisi faced no respiratory limitations on speech.

In contrast, the 1984 discovery in Kenya of a boy's 1.6-million-year-old skeleton, identified by some researchers as H. erectus and by others as Homo ergaster, yielded small, chimplike vertebrae. Researchers initially suspected that the ancient youth and his presumably small-spined comrades lacked the respiratory control to talk as people do today."

Old man with one tooth, cooking or shellfish food?
In the new work, David Lordkipanidze of the Georgian State Museum in Tbilisi and his colleagues describe a skull and jawbone from a hominid male who had lost all but one tooth. The tooth sockets had been resorbed into the skull, suggesting that he had lost the teeth several years before dying. The discovery represents the earliest case of severe masticatory impairment in the fossil record yet found, the researchers say.

Near the site of their latest find, the scientists also uncovered stone artifacts and animal bones with toolmarks on them. In order to survive without the ability to chew or bite meat, the gummy individual would have needed to collect sufficient soft food, including bone marrow, brain matter or soft plant food. Such gathering or processing could have been done alone, but the scientists posit that other individuals may have helped because of the individual's advanced age or illness, either of which could have been responsible for the loss of his teeth. The discovery, the authors conclude, "raises interesting questions regarding social structure, life history and subsistence strategies of early Homo that warrant further investigation." --Sarah Graham

Dmanisi site had both African ostriches, Kudaro macaques and short-necked giraffes and EurAsian wolves, sabercats and EurAsian beavers (skull wider than neolithic Polish beaver which were larger and faster growing than modern EurAsian beavers).
Simple stone pebble tools were used, probably with stick tools.
BUR CZAK-ABRAMOWICZ N. The beaver and some other interesting animals in Caucasus. PrzeglÄ…d Zool. 8, 51, 1964. [in Polish]
Dmanisi seems to have dried out after the pliocene/pleistocene border.

Black Sea beaver species plentiful from Miocene to Pleistocene:

Conjecture: ARC Diving was synchronized tandem Aqua-photic Respiratory Cycle dive foraging, when one partner dove down to the benthos the other backfloated above, communication was retained via clicks (at depth) and tones (at surface) which eventually merged to become uniquely human click-consonant tonal speech. ARC diving included in complement the Mammalian Diving Reflex (MDR), engaged upon submergence optimally conserving oxygen, the Photic Sneeze (or Surfacing) Reflex (PSR), engaged upon emergence at the surface, optimally exchanged carbon dioxide and oxygen-rich air. The combination of descent and ascent reflexes allowed sustained dive foraging for coastal seafood in sub/tropical lagoons, while seasonal inland freshwater herbs/rhyzomes were harvested by shoreside shallow wading, especially around Eurasian beaver-dammed woodland/wetland ponds and Peri-Tethyan estuaries. Caves and rockshelters offered sleeping sites in addition to wood-stick and reed-plastered dome huts.

Chicken pox can be spread by humans to apes, per a zoo account. Unknown if mumps are uniquely human, as I conjectured earlier.

Borneo frog breathes through skin, lost lungs, better hydrodynamics and less ascents.
A frog that breathes through its skin because it has no lungs, which makes it appear flat. This aerodynamic shape allows the frogs to move swiftly in fast flowing streams.
Neandertal face long, modern human face short:

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