"Birth canals are different all over the world, countering a long-held evolutionary theory"

"The idea that women’s pelvises have been shaped by an evolutionary compromise—also known as the “obstetrical dilemma”—has been influential in anthropology, says Jonathan Wells, an expert in human evolution at University College London who was not involved with the work. But recent studies have challenged it, and the new findings add to that research, he says. If the obstetric dilemma held true, one would expect birth canals around the world to be relatively standardized, Wells says. But that’s not what researchers found... 

Betti and Manica also found that there was less variability in birth canal shape in populations farther from Africa, such as Native Americans. That pattern has been seen in other traits, and is thought to simply reflect lower variability in genes and traits among the relatively small bands of people who moved out of Africa to populate the world. Overall, the analysis suggests a population may have ended up with a particular birth canal shape simply by chance, not because of any sort of selective pressure."

https://www.sciencemag.org/news/2018/10/birth-canals-are-different-all-over-world-countering-long-held-evolutionary-theory?utm_source=6&utm_medium=social&utm_campaign=AAAS---The-American-Association-for-the-Advancement-of-Science-%28AAAS.Science%29&utm_term=WebEd&utm_content=AAAS&fbclid=IwAR0SnUPDfLzQZhofUJPcYaQnqovXzVhp5hNOSI-pMKPm4udlgfaw8jGF4-I

HOW is this the first time this has been investigated?? So, so many health implications for pregnancy. 

Related : terrible pregnancy one(s), change to theory about birth canals and women