Posted on 03/20/2008 2:54:39 PM PDT by blam
Upright Walking Began 6 Million Years Ago
Newswise — A shape comparison of the most complete fossil femur (thigh bone) of one of the earliest known pre-humans, or hominins, with the femora of living apes, modern humans and other fossils, indicates the earliest form of bipedalism occurred at least six million years ago and persisted for at least four million years. William Jungers, Ph.D., of Stony Brook University, and Brian Richmond, Ph.D., of George Washington University, say their finding indicates that the fossil belongs to very early human ancestors, and that upright walking is one of the first human characteristics to appear in our lineage, right after the split between human and chimpanzee lineages. Their findings are published in the March 21 issue of the journal Science.
The research is the first thorough quantitative analysis of the Orrorin tugenensis fossil – a fragmentary piece of femur – which was discovered in Kenya in 2000 by a French research team. Dr. Jungers, Chair of Anatomical Sciences at SBU School of Medicine, and Dr. Richmond, Associate Professor of Anthropology at GWU and a member of GWU’s Center for the Advanced Study of Hominid Paleobiology, completed a multivariate analysis of the proximal femora shape of a young adult O. tugenensis that enabled them to pinpoint the pattern of bipedal gait for this controversial hominin. Their analysis included a large and diverse sample of apes, other early hominins, including Australopithecus, and modern humans of all body sizes.
“This research solidifies the evidence that the human lineage split off as far back as six million years ago, that we share ancestry with Orrorin, and that our ancestors were walking upright at the time,” says Dr. Richmond. “These answers were not clear before this analysis.”
“Our study confirms that as early as six million years ago, basal hominins in Africa were already similar to later australopithecines in their anatomy and inferred locomotor biomechanics,” adds Dr. Jungers. “At the same time, by way of the analysis, we see no special phylogenetic connection between Orrorin and our own genus, Homo.”
In “Orrorin tugenensis Femoral Morphology and the Evolution of Hominin Bipedalism,” the authors articulate that the analysis and morphological comparisons among femora from the fossils showed that O. tugenensis is distinct from those of modern humans and the great apes in having a long, anteroposteriorly narrow neck and wide proximal shaft. Early Homo femora have larger heads and broader necks compared to early hominins. In addition to these features, modern human femora have short necks and mediolaterally narrow shafts.
The challenge ahead, explains Dr. Jungers, is “to identify what precipitated the change from this ancient and successful adaptation of upright walking, and climbing, to our own obligate form of bipedalism.”
The Department of Anatomical Sciences at Stony Brook University School of Medicine is known internationally for the scope and significance of its research into evolutionary morphology, including paleoanthropology, field-based vertebrate paelontology and experimental functional anatomy. The department interacts with other departments in the School of Medicine, as well as those in Biological Sciences and the Department of Anthropology, through which the Interdepartmental Doctoral Program in Anthropological Sciences (IDPAS) is administered. The Stony Brook IDPAS faculty brings world-renowned strengths in functional morphology and human evolution.
“Evolution is a fact.”
...for varying definitions of the word “Evolution”.
*drool*
*slurp*
*glaze*
:::HELP:::
And the meaning of "is" is?
I see you’re “In the thick of the Muslim world”.
They’re stuck in the 7th century, what century are you in?
Look into my eyez....
If you guys are that sure you are right, then why get so defensive.? What is wrong with encouraging people to check out what they hear, and ask questions, whether about “the beginning, politics etc”
*spirals*
*drool*
*slack jaw*
I.
Am.
Your.
Willing.
Salve.
Master.
*drool*
come to me...
*drool*
*slaver*
Yes.
Master.
*drool*
*spiral*
What’s defensive about stating the truth?
I didn’t call you names.
Please explain to me what I said that was defensive.
People can check out whatever they want. They’re even free to create their alternate reality with leprachauns, gnomes, or whatever. I have a younger brother that believes in that crap.
Is it defensive to assert that science doesn’t support the concept of gnomes?
Say you asked “Why did this nation become a Democracy?” and I pointed out that we are not a Democracy, and Democracy was anathema to our founders; would you assume I was against you asking questions, or that I had specific problems with the specifics of the question?
Your statement that this was ‘just a theory’ shows that you have little concept of what a theory actually is. That you object to this being portrayed as ‘fact’ you show that you do not understand that theories are ABOVE facts in the hierarchy of Scientific Explanation.
It was as if we were talking about the conduct of a lieutenant and you came along and said “you know he is just a Colonel don't you?”; you would be elevating the subject without cause in an attempt to discredit the subject by applying a term that denotes MORE confidence.
I’ll lay in a case, just in case...
Well, spontaneous mutation and natural selection within species is fact. However, the notion that primitive species evolve into more sophisticated species is not fact. In fact, it appears to violate the second law of thermodynamics.
People who are uncomfortable the implications of this, postulate that infinite energy has been added to earth's ecoshere so that evolution is, in fact, possible.
Evolution is a fact.
_________________________
Which aspect is a fact?
Spike?
*drool*
*whispers*
:::Could we have chocolate with that case?:::
It was kind of cool when the girls Ironed their hair, long blond and smoking, lumpy know, time passes.
No, the 2nd law of thermodynamics in no way contradicts increasing complexity; this is an argument that even other creationists caution creationists not to use.
Earth is not a closed system and it would not take ‘infinite’ energy to allow for evolution (indeed infinite energy would destroy life) all it takes is a steady stream of energy from something we like to call Mr. Sun.
The fact that nothing on earth is a perfect replicator (mutation creates genetic diversity) and that natural selection acts on variation by increasing or decreasing the incidence of this variation based upon the relative advantage or disadvantage it confers.
Evolution happens every time. There is in fact no way to stop it.
Take a single bacteria and plate it and grow up a colony from that one specimen. Now plate that colony on 10 different plates and subject them to 10 different selective pressures (heat, cold, antibiotics, etc) and you will find that variation that did not exist within the original specimen is present in these selected colonies, and that these variations tend to allow for living in these adverse conditions. It happens every time.
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