ZIRA: Cornelius has developed a brilliant hypothesis -
CORNELIUS (quickly) It's probably wrong --
ZIRA -- that the ape evolved from a lower order of primate, possibly man
Posted on 10/10/2007 12:15:58 PM PDT by Dallas
The ancestors of humanity are often depicted as knuckle-draggers, making humans seem unusual in our family tree as "upright apes."
In other words, "the other great apes we see now, such as chimps or gorillas or orangutans, might have descended from human-like ancestors," researcher Aaron Filler, a Harvard-trained evolutionary biologist and medical director at Cedars-Sinai Institute for Spinal Disorders in Los Angeles, told LiveScience.
Filler analyzed how the spine was assembled in more than 250 living and extinct mammalian species, with some bones dating up to 220 million years old.
He discovered a series of changes that suggest walking upright-and not with our knuckles-might actually have been the norm for the ancestors of today's great apes.
In most creatures with a backbone, the body is separated roughly in half by a tissue structure that runs in front of the spinal canal. This "horizontal septum" divides the body into a dorsal part (corresponding to the back side of humans), and a ventral part (or the front half).
A strange birth defect in what may have been the first direct human ancestor led this septum to cross behind the spinal cord in the lumbar or lower back region-an odd configuration more typical of invertebrates. This would have made horizontal stances inefficient.
"Any mammal with this set of changes would only be comfortable standing upright," Filler said. "I would envision this malformed young 'hominiform'-the first true ancestral human-as standing upright from a young age," he added, while the rest of the mutant's family and species continued to walk around "on all fours."
This change to an upright posture could have occurred "very abruptly, with just a few shifts in 'homeotic' genes, or ones responsible for how the body plan is laid out," Filler said.
The earliest known bipedal apes-those walking on two legs-were thought to date back as far as some 6 million years or so. Now Filler's new findings suggest the earliest upright ape known so far was the extinct hominoid, Morotopithecus bishopi, which lived in Uganda more than 21 million years ago.
"Humanity can be redefined as having its origin with Morotopithecus," Filler said. He detailed his findings online Oct. 10 in the journal PLoS ONE.
This research pushes back the date for the origins of bipedalism roughly 15 million years, to before the last common ancestor of humans, chimps, gorillas and orangutans, as well as lesser apes such as gibbons. The results match up with recent findings that suggest upright walking might have started before humanity's ancestors even left the trees.
"If you look at baby siamangs, which are a kind of gibbon, you'll see them walk bipedally on their own," Filler said. "It's just their natural way of walking. They never knuckle walk."
If bipedalism did evolve 21 million years ago, it more likely evolved to walk in trees than on the ground, said University of Chicago evolutionary anthropologist Russell Tuttle. "Twenty-one million years ago, there were a lot of trees around," he said.
Besides Morotopithecus, fossil vertebrae suggest three other upright ape species precede the 6 million year mark, Filler added.
"So you have this fossil evidence for bipedalism, and you have apes such as gibbons," he said. "Perhaps humans represent the primitive condition, and knuckle walkers such as chimps and gorillas are modified."
The ancestors of chimps and gorillas might have evolved knuckle walking as a speedier mode of travel, Filler suggested. If bipedalism did come first, that means gorillas and chimpanzees might have evolved knuckle walking independent of each other. Future analysis of the genes of those apes could show they came across knuckle walking in different ways, supporting Filler's ideas.
"I am getting the feeling that a revolution in our thinking about the origins of bipedality is now under way," said evolutionary anthropologist Robin Crompton at the University of Liverpool in England.
Queue the Helen Thomas and Hanoi John pics! :)
Primates are God’s joke on mankind. He did it to mess with Liberals’ minds.
IBTFDUC!
(In before the first DU crack)
But God hath chosen the foolish things of the world to confound the wise; and God hath chosen the weak things of the world to confound the things which are mighty;
1 Cor 1:27
:-)
He’s suggesting that the great apes of today used to walk upright.
ZIRA: Cornelius has developed a brilliant hypothesis -
CORNELIUS (quickly) It's probably wrong --
ZIRA -- that the ape evolved from a lower order of primate, possibly man
Interesting.
I wonder if such a mutation could explain the bipedalism of Oliver, the humanzee?
GGG ?
It’s not evolution in reverse, because evolution doesn’t have a direction. In many environments brachiation — swinging from tree limb to tree limb — makes much more evolutionary sense than bipedal locomotion. A gibbon in a forest can move much quicker than a human being can, which makes it easier to get to tasty plants high in the forest canopy and also evade predators.
But wouldn’t that mean they had evolved ?
Where did that researcher come from? Was that Pakistan or Saudi?!
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Thanks Fractal Trader. It's against my better judgment to add this topic, but I hardly ever use that anyway. :') I won't ping, because I think we may have had a similar topic some months back. Thanks again. |
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