Friday, April 30, 2010

Sloths & jitterbugging heart & earth & dive foraging

marine sloth
outhouse sloth

layers of the heart
rotary venticular blood flow & torsion of heart muscle similar to VE jitterbug transform, with opposing heart muscle groups (123 45 678) :
Note pic 14, similar to tao/dau symbol or rolling surf wave, and general similar form of heart to a marine snail, which filter feeds and breathes by pumping seawater through gills and gut tissue.

"Pettigrew14 performed careful dissection of the heart of mammals and man, demonstrating 7 muscle layers. The three outer layers spiral with an increasing angle from the perpendicular, while the fourth layer is horizontal. The three inner layers spiral in the opposite direction, increasing toward the vertical. The layers are arranged in opposition so that 1 opposes 7, 2 opposes 6, and 3 opposes 5, with the fourth layer being a connecting layer (tensional frame?)."



6,000 year old human artifacts contains indications of 3/4 protein from marine diet

Quantitative evaluation of marine protein contribution in ancient diets
based on nitrogen isotope ratios of individual amino acids in bone collagen:
An investigation at the Kitakogane Jomon site
YI Naito, NV Honch, Y Chikaraishi, N Ohkouchi, M Yoneda 2010 AJPA

Nitrogen stable isotopes analysis of individual bone collagen amino acids
was applied to archeological samples as a new tool for assessing the
composition of ancient human diets and calibrating radiocarbon dates. We
used this technique to investigate human and faunal samples from the
Kitakogane shell midden in Hokkaido, Japan (5,300-6,000 cal BP). Using
compound-specific nitrogen isotope analysis of individual amino acids, we
aimed to estimate i) the quantitative contribution of marine and terrestrial
protein to the human diet, and ii) the mean trophic level (TL) from which
dietary protein was derived from marine ecosystems. Data were interpreted
with reference to the amino acid trophic level (TLAA) model, which uses
empirical amino acid 15N from modern marine fauna to construct mathematical
equations that predict the trophic position of organisms. The TLAA model
produced realistic TL estimates for the Kitakogane marine animals. However,
this model was not appropriate for the interpretation of human amino acid
15N, as dietary protein is derived from both marine and terrestrial
environments. Hence, we developed a series of relevant equations that
considered the consumption of dietary resources from both ecosystems. Using
these equations, the mean percentage of marine protein in the Kitakogane
human diet was estimated to be 74%.

Diaphragmatic contractions pump oxygen to the brain during hypoxia, increasing the cerebral blood flow volume. Involuntary breathing movements improve cerebral o... [J Appl Physiol. 2009] - PubMed result

We investigated whether the involuntary breathing movements (IBM) during the struggle phase of breath holding, together with peripheral vasoconstriction and progressive hypercapnia, have a positive effect in maintaining cerebral blood volume. The central hemodynamics, arterial oxygen saturation, brain regional oxyhemoglobin (bHbO(2)), deoxyhemoglobin, and total hemoglobin changes and IBM were monitored during maximal dry breath holds in eight elite divers. The frequency of IBM increased (by approximately 100%), and their duration decreased ( approximately 30%), toward the end of the struggle phase, whereas the amplitude was unchanged (compared with the beginning of the struggle phase). In all subjects, a consistent increase in brain regional deoxyhemoglobin and total hemoglobin was also found during struggle phase, whereas bHbO(2) changed biphasically: it initially increased until the middle of the struggle phase, with the subsequent relative decline at the end of the breath hold. Mean arterial pressure was elevated during the struggle phase, although there was no further rise in the peripheral resistance, suggesting unchanged peripheral vasoconstriction and implying the beneficial influence of the IBM on the cardiac output recovery (primarily by restoration of the stroke volume). The IBM-induced short-lasting, sudden increases in mean arterial pressure were followed by similar oscillations in bHbO(2). These results suggest that an increase in the cerebral blood volume observed during the struggle phase of dry apnea is most likely caused by the IBM at the time of the hypercapnia-induced cerebral vasodilatation and peripheral vasoconstriction.

Levant 800ka - (Hula/Jordan, fire, food prep) African Rift drought
doi 10.1016/j.jhevol.2010.03.007
The paleoclimate of the Eastern Mediterranean during the transition from
early to mid Pleistocene (900 to 700 ka) based on marine and non-marine
records: an integrated overview
Ahuva Almogi-Labin 2010 JHE

Climate change is frequently considered an important driver of hominin
evolution and dispersal patterns. The role of climate change in the last
phase (900­700 ka) of the Middle Pleistocene Transition (MPT) in the Levant
and northeast Africa was examined, using marine and non-marine records.
During the MPT the global climate system shifted from a linear 41 k.yr. into
a highly non-linear 100 k.yr. system, considerably changing its global
modulation. Northeast Africa aridity further intensified around 950 ka, as
indicated by a sharp increase in dust flux, and a jump to overall higher
levels thereafter, coinciding with a lack of sapropels in the deep eastern
Mediterranean (930­690 ka). The increased dust flux centering at 800 ka
corresponds to the minima in 400 k.yr. eccentricity, a minima in 65 °N solar
forcing and in the weakest African monsoon precession periodicity. This
resulted in expansion of hyper-arid conditions across North Africa, the
lowest lake levels in eastern Africa and the lowest rainfall in the Nile
River headwaters. In the eastern Mediterranean an increasing continental
signature is seen in glacial stages 22 (880 ka) and 20 (800 ka). Lower
arboreal pollen values also indicate arid conditions during these glacial
stages. The southern and eastern parts of the Negev Desert, unlike its
northern part, were hyper-arid during the MPT, making them highly
unsustainable. The fluctuations in the stands of Lake Amora follow global
climate variability but were more moderate than those of its last glacial
Lake Lisan successor. In the northern Jordan-Valley Hula Lake, frequent
fluctuations in lake level coincide with both global climate changes and
minor changes in water salinity varying from fresh to oligohaline. It
appears therefore that the most pronounced and widespread deterioration in
climate occurred in northeast Africa from 900 to 700 ka, whereas in the
Levant the corresponding climatic changes were more moderate.

Warmbloodedness & respiration in dinosaurs and mammoths

A Clarke & H-O Poertner 2010 Biol.Rev.PRESS
Temperature, metabolic power, and the evolution of endothermy

Endothermy has evolved at least twice, in the precursors to modern mammals
and birds. The most widely accepted explanation for the evolution of
endothermy has been selection for enhanced aerobic capacity. We review this
hypothesis in the light of advances in our understanding of ATP generation
by mitochondria and muscle performance. Together with the development of
isotope-based techniques for the measurement of metabolic rate in
free-ranging vertebrates, these have confirmed the importance of aerobic
scope in the evolution of endothermy: absolute aerobic scope, ATP generation
by mitochondria, and muscle power output are all strongly
temperature-dependent, indicating that there would have been significant
improvement in whole-organism locomotor ability with a warmer body. New data
on mitochondrial ATP generation and proton leak suggest that the thermal
physiology of mitochondria may differ between organisms of contrasting
ecology and thermal flexibility. Together with recent biophysical modelling,
this strengthens the long-held view that endothermy originated in smaller,
active eurythermal ectotherms living in a cool but variable thermal
environment. We propose that rather than being a secondary consequence of
the evolution of an enhanced aerobic scope, a warmer body was the means by
which that enhanced aerobic scope was achieved. This modified hypothesis
requires that the rise in metabolic rate, and the insulation necessary to
retain metabolic heat, arose early in the lineages leading to birds and
mammals. Large dinosaurs were warm, but were not endotherms, and the
metabolic status of pterosaurs remains unresolved.

KL Campbell cs 2010 Nature Genetics PRESS
Substitutions in woolly mammoth hemoglobin confer biochemical properties
adaptive for cold tolerance

We have genetically retrieved, resurrected and performed detailed
structure-function analyses on authentic woolly mammoth hemoglobin to reveal
for the first time both the evolutionary origins and the structural
underpinnings of a key adaptive physiochemical trait in an extinct species.
Hemoglobin binds and carries O2; however, its ability to offload O2 to
respiring cells is hampered at low temperatures, as heme deoxygenation is
inherently endothermic (that is, hemoglobin-O2 affinity increases as
temperature decreases). We identify amino acid substitutions with large
phenotypic effect on the chimeric ¦Â/¦Ä-globin subunit of mammoth
that provide a unique solution to this problem and thereby minimize
energetically costly heat loss. This biochemical specialization may have
been involved in the exploitation of high-latitude environments by this
African-derived elephantid lineage during the Pleistocene period. This
powerful new approach to directly analyze the genetic and structural basis
of physiological adaptations in an extinct species adds an important new
dimension to the study of natural selection.

No comments: