WASHINGTON — With all that growing weight up front, how is it that pregnant women don't lose their balance and topple over?(Pete: Evolutionary "engineering"? ENGINEERING?)
Scientists think they've found the answer: There are slight differences between women and men in one lower-back vertebra and a joint in the hip, which allow women to adjust their center of gravity.
This elegant evolutionary engineering is seen only in female humans and our immediate ancestors who walked on two feet, but not in chimps and apes, according to a study published in Thursday's journal Nature.
"That's a big load that's pulling you forward," said Liza Shapiro, an anthropology professor at the University of Texas and the only one of the study's three authors who has actually been pregnant. "You experience discomfort. Maybe it would be a lot worse if the design changes were not there."(Pete: Design changes? What does that mean? Since when can Darwinists help themselves to the word "design"? I thought that "design" was "unscientific!")
Harvard anthropology researcher Katherine Whitcomb found two physical differences in male and female backs that until now had gone unnoticed: One lower lumbar vertebra is wedged-shaped in women and more square in men, and a key hip joint is 14 percent larger in women than men when body size is taken into account.(Pete: Sounds like "reverse engineering" to me. And guess what… you can only "reverse engineer" something that was engineered in the first place.)
The researchers did engineering tests that show how those slight changes allow women to carry the additional and growing load without toppling over — and typically without disabling back pain.
"When you think about it, women make it look so very damn easy," Whitcomb said. "They are experiencing a pretty impressive challenge. Evolution has tinkered ... to the point where they can deal with the challenge."(Pete: So then there WAS a point in time where pregnant females did NOT 'deal with the challenge'? Does that mean that at one time they DID 'topple over'? How did Natural Selection preserve those generations whose pregnant females would topple over? Didn't that cause injury? Wouldn't they be more vulnerable to predators in that state? Wasn't it more difficult to survive without that ability?)
"It's absolutely beautiful," she said. "A little bit of tinkering can have a profound effect."(Pete: Of course it's beautiful. But can a blind, purposeless process like evolution actually "tinker"? Doesn't "tinkering" imply intelligence?)
Walking on two feet separates humans from most other mammals. And while anthropologists still debate the evolutionary benefit of walking on two feet, there are notable costs, such as pain for pregnant females. Animals on all fours can better handle the extra belly weight.(Pete: Either that or the human frame was designed that way from the get-go, with males and females having slight variations in structure to accommodate the different roles. Which do you think is more reasonable?)
The back changes appear to have evolved to overcome the cost of walking on two feet, said Harvard anthropology professor Daniel Lieberman.
I'm with Pete. And I suppose the even broader lesson here is this... If, in attempting to support a particular position, you frequently find yourself using terms that logically belong only to the opposite position, it's time to rethink your paradigm.