We’ve heard this before but anyway:
Bipedalism developed around seven million years ago and dramatically reshaped the hominin pelvis into a real birth canal. Larger brains, however, didn’t start to develop until two million years ago, when the earliest species of the genus Homo emerged. The evolutionary solution to the dilemma brought about by these two conflicting evolutionary forces was to give birth to neurologically immature and helpless newborns with relatively small brains — a condition known as secondary altriciality.
A research group led by Martin Häusler from the Institute of Evolutionary Medicine at the University of Zurich (UZH) and a team headed up by Pierre Frémondière from Aix-Marseille University have now found that australopithecines, who lived about four to two million years ago, had a complex birth pattern compared to great apes. “Because australopithecines such as Lucy had relatively small brain sizes but already displayed morphological adaptations to bipedalism, they are ideal to investigate the effects of these two conflicting evolutionary forces,” Häusler says.University of Zurich, “Complex human childbirth and cognitive abilities a result of walking upright” at ScienceDaily (May 10, 2022)
The explanation sounds rather contrived and, curiously, makes “evolution” sound like a theistic evolutionist’s God.
The paper is open access.
More on bipedality/bipedalism: Paleontologist: Humans walked on two legs from the beginning Carol Ward: It seems to be a behavior that was present in some of the earliest members of our branch of the family tree. It represented what was really the initial major adaptive change from any apelike creature that came before us.
Researchers: Supernova prompted humans to walk upright Funny, if bipedalism originated in a global catastrophe, that it never occurred to any other primate to resolve the problem by becoming fully bipedal. But keep thinking. Resist groupthink.
Bipedalsm: Regulatory area cent.com/intelligent-design/bipedalism-regulatory-area-missing-in-humans/” target=”another”>missing in humans
Researcher: To Understand Human Bipedalism, Stop Assuming “A Chimpanzee Starting Point”
Rough terrain caused humans to start walking upright
Early bipedalism walked no straight line
We’ve also heard that bipedalism developed so we could hit each other. Or carry infants. Or scarce resources. Or save energy. Or cool down. But mainly so we could have our hands free for whatever. (Saving eneregy and cooling down don’t really count here because lots of other methods would have worked; they just wouldn’t have freed the hands at the same time.)
See also “I’m Walkin’, Yes Indeed I’m Walkin’” But Not Because It’s Necessarily a Better Way to Get Around
Also, Design perspectives and the physiology of walking