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  An ecology based approach to understanding human origins         


Author: Claudius Denk
Date: Jul 31, 2008 15:26

An ecology based approach to understanding human origins

New species don't just spring up out of the blue. They are part and
parcel to new biomes (ecosystems). Likewise new biomes don't just
spring up out of the blue, they are the result of changes in
environments/climatic...
Show full article (24.26Kb)
8 Comments
  Weird eBay auction: Wooly Mammoth DNA hair strand trading card         


Author: AC
Date: Jul 31, 2008 07:35

Beckett Behind the Scenes: "This one is just plain nuts..."

http://snipr.com/MammothHair
1 Comment
  A dinosaur stepped on a human footprint: repent now.         


Author: Lin Liangtai
Date: Jul 31, 2008 06:15

A dinosaur stepped on a human footprint: repent now.

Fig. 1 below shows a fossilized human footprint which was stepped on
by a dinosaur:
Fig. 1 : http://www.wretch.cc/album/show.php?i=lin440315&b=20&f=1555209943&p=68

Original photo:
http://www.mineralwellsindex.com/local/images_sizedimage_210094837/resources_pho...
Article with the orginal photo:
http://www.mineralwellsindex.com/local/local_story_210093256.html
5 Comments
  Re: dense bones equal fast runners         


Author: Lee Olsen
Date: Jul 29, 2008 20:47

Mujin wrote:
> [...]
> "Conclusions: Running, a weight-bearing exercise, is associated with more
> favorable geometric and biomechanical characteristics in relation to bone
> strength, compared with the weight supported activities of swimming and
> cycling. Differences may reflect skeletal adaptations to the specific
> mechanical-loading patterns inherent in these sports"
> http://www.acsm-msse.org/pt/re/msse/abstract.00005768-200204000-
> 00018.htm;jsessionid=HJxhg51XTP76vm2Q2tjGNy9JTQCZFcv3xHG8Qh2XL470Kzjk7kPB!-
> 1601909834!181195629!8091!-1
> Clearly weight bearing, high impact activity increases cortical thickness
> and decreases medullary cavity sizes. More importantly:
Show full article (9.64Kb)
8 Comments
  Re: savanna running facts         


Author: Lee Olsen
Date: Jul 29, 2008 20:43

Mujin wrote:
> [...]
> "Conclusions: Running, a weight-bearing exercise, is associated with more
> favorable geometric and biomechanical characteristics in relation to bone
> strength, compared with the weight supported activities of swimming and
> cycling. Differences may reflect skeletal adaptations to the specific
> mechanical-loading patterns inherent in these sports"
> http://www.acsm-msse.org/pt/re/msse/abstract.00005768-200204000-
> 00018.htm;jsessionid=HJxhg51XTP76vm2Q2tjGNy9JTQCZFcv3xHG8Qh2XL470Kzjk7kPB!-
> 1601909834!181195629!8091!-1
> Clearly weight bearing, high impact activity increases cortical thickness
> and decreases medullary cavity sizes. More importantly:
Show full article (2.36Kb)
no comments
  News: 'Chicken and chips' theory of Pacific migration         


Author: Robert Karl Stonjek
Date: Jul 29, 2008 19:53

'Chicken and chips' theory of Pacific migration

A new study of DNA from ancient and modern chickens has shed light on the controversy about the extent of pre-historic Polynesian contact with the Americas.

The study questions recent claims that chickens were first introduced into South America by Polynesians, before the arrival of Spanish chickens in the 15th century following Christopher Columbus.

It is published this week in the Proceedings of the National Academy of Sciences USA (July 28) by an international research group, including scientists from the University of Adelaide's Australian Centre for Ancient DNA (ACAD).

ACAD Director Professor Alan Cooper says there has been considerable debate about the existence and degree of contact between Polynesians and South Americans, with the presence of the sweet potato throughout the Pacific often used as evidence of early trading contacts.

"Similarly, Polynesians are known to have spread chickens across the Pacific at least as far as Easter Island, but were not thought to have introduced them to South America," he says.

A recent study claimed to have found the first direct evidence of a genetic link between ancient Polynesian and apparently pre-Columbian chickens from archaeological sites in Chile, supporting the idea that there was extensive contact between Polynesia and South America and that chicken and 'chips' had been traded in opposite directions.

The current work challenges this conclusion however, by generating DNA data from 41 native Chilean chicken specimens, and comparing these with over 1000 modern domestic chickens from around the world, and the previously published DNA from Polynesian and Chilean chicken bones.

"The results showed that the ancient Polynesian and Chilean chickens possessed a genetic sequence that is the most common in the world today, the so-called 'KFC' gene" Professor Cooper says.

"This sequence would undoubtedly have been common in the early Spanish chickens, and therefore provides no evidence of Polynesian contact. So while we can say the KFC chicken was popular amongst early Polynesian voyagers, we certainly can't use it as evidence for trade with South America".

The researchers did find a highly unusual DNA sequence in the ancient Easter Island chickens, which originate from Indonesia or the Philippines, but this apparently did not get passed on to South America. "This is important because Easter Island is commonly thought of as a major jumping off point for Polynesian contact with South America," says team member and ACAD PhD student Nicolas Rawlence.

According to project leader Dr Jaime Gongora from Sydney University, many people in South America like to believe they are descendants of Polynesians.

"This study does not disprove this idea, but we have found no evidence to support pre-historic contact."

Source: University of Adelaide
http://www.physorg.com/news136544792.html

--
Posted by
Robert Karl Stonjek

'Chicken and chips' theory of Pacific
migration
A new study of DNA from ancient
and modern chickens has shed light on the controversy about the extent of
pre-historic Polynesian contact with the
Americas...
Show full article (5.86Kb)
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  osteosclerosis = hallmark of an aquatic lifestyle         


Author: Marc Verhaegen
Date: Jul 29, 2008 18:32

Bone Thickness in Homo erectus
Kennedy GE 1985 JHE 14: 699-708
The presence of such thickened bone (in erectus) is extraordinary; very
few animals (mammal or non-mammal) show similar generalized thickened bone.
Within the order Sirenia, the families Manatidae (Manatees) and the
Halicoridae (dugongs) show not merely thickened bone and medullary stenosis
but complete lack of medullary canal (Fawcett 1942) Š The adaptive advantage
of such heavy, dense bone to the sirenians is apparently to counterbalance
the buoyancy of their large lung volume while submerged. Amedullary bones,
presumably reflecting a similar selective pressure, are also found in
certain Mesozoic marine reptiles (Fawcett 1942) and in living humpback
whales (Ogden 1980).
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  savanna running nonsense         


Author: Marc Verhaegen
Date: Jul 29, 2008 17:39

The increased density of the pakicetid skeleton would have left these early
cetaceans wholly unsuited to running, or even prolonged terrestriality, as
heavy skeletons are energetically expensive to move.(so obvious, but still
not well understood by savanna believers) In addition, the
hypermineralization (osteopetrosis) of pakicetid load bearing elements put
them at increased risk for fracture during terrestrial loading (de Vernejoul
and Bénichou, 2001), a risk that rises with velocity.(idem: dense bone is
more brittle) Thus, although they look superficially similar to their
cursorial relatives, it is likely that pakicetids made few sustained
terrestrial forays. The summed evidence of bone gross morphology and
microstructure indicates that pakicetid cetaceans were fully committed to an
aquatic...
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  "Homo erectus inhabited seacoast environments"         


Author: Marc Verhaegen
Date: Jul 29, 2008 15:56

Sedimentological and paleogeographical context of the Mojokerto hominin
site, East Java :92 abstr.67th ann.meet.Soc.Vert.Paleontol.
J.vert.Paleontol.27 suppl.nr.3
F Huffman, R Buffler, J Kappelman, D Ruez & Y Zeim 2007

... the discovery site lies above marine Mollusk Mbr II & within a
fossiliferous pebbly sandstone in the upper Pucangan Fm. The sandstone is a
fluvial deposit with a broad channelized base, prominent cross...
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  NASA angered God and ghosts in trying to colonize graveyard Mars.         


Author: Lin Liangtai
Date: Jul 28, 2008 03:01

no comments
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