Human evolution: Little foot analyzed (Introduction)

by David Turell , Tuesday, April 20, 2021, 21:21 (1095 days ago) @ David Turell

Older than Lucy, ape-like upper, bipedal legs:

https://www.sciencedaily.com/releases/2021/04/210420092921.htm

"Although other parts of Little Foot, especially its legs, show humanlike traits for upright walking, the shoulder components are clearly apelike, supporting arms surprisingly well suited for suspending from branches or shimmying up and down trees rather than throwing a projectile or dangling astride the torso like humans.

"The Little Foot fossil provides the best evidence yet of how human ancestors used their arms more than 3 million years ago, said Kristian J. Carlson, lead author of the study and associate professor of clinical integrative anatomical sciences at the Keck School of Medicine.

"'Little Foot is the Rosetta stone for early human ancestors," he said. "When we compare the shoulder assembly with living humans and apes, it shows that Little Foot's shoulder was probably a good model of the shoulder of the common ancestor of humans and other African apes like chimpanzees and gorillas."

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"The Little Foot fossil is a rare specimen because it's a near-complete skeleton of an Australopithecus individual much older than most other human ancestors. The creature, probably an old female, stood about 4 feet tall with long legs suitable for bipedal motion when it lived some 3.67 million years ago. Called "Little Foot" because the first bones recovered consisted of a few small foot bones, the remains were discovered in a cave in South Africa in the 1990s. Researchers have spent years excavating it from its rock encasement and subjecting it to high-tech analysis.

"While not as widely known as the Lucy skeleton, another Australopithecus individual unearthed in East Africa in the 1970s, Carlson said Little Foot is older and more complete.

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"The scientists compared the creature's shoulder parts to apes, hominins and humans. Little Foot was a creature adapted to living in trees because the pectoral girdle suggests a creature that climbed trees, hung below branches and used its hands overhead to support its weight.

"For example, the scapula, or shoulder blade, has a big, high ridge to attach heavy muscles similar to gorillas and chimpanzees. The shoulder joint, where the humerus connects, sits at an oblique angle, useful for stabilizing the body and lessening tensile loads on shoulder ligaments when an ape hangs beneath branches. The shoulder also has a sturdy, apelike reinforcing structure, the ventral bar. And the collarbone has a distinctive S-shaped curve commonly found in apes.

"Those conclusions mean that the structural similarities in the shoulder between humans and African apes are much more recent, and persisted much longer, than has been proposed, Carlson said.

"'We see incontrovertible evidence in Little Foot that the arm of our ancestors at 3.67 million years ago was still being used to bear substantial weight during arboreal movements in trees for climbing or hanging beneath branches," he said. "In fact, based on comparisons with living humans and apes, we propose that the shoulder morphology and function of Little Foot is a good model for that of the common ancestor of humans and chimpanzees 7 million to 8 million years ago.'"

Comment: The conclusion is obvious: first down from the trees, then later arm and hand dexterity development, and finally brain enlargement followed by brain complexity, driven by what natural force, if any? Noting chimps remained essentially unchanged, why did we bother to keep changing. I will always believe God did it.