Human variation in the shape of the birth canal is significant and geographically structured

Proceedings of the Royal Society B • Vol/Iss. 285(1889) • The Royal Society Publishing • • Published In • Pages: 1-9 •
By Betti, Lia, Manica, Andrea

Abstract

The 'obstetrical dilemma' postulates that human females evolved a pelvis shape that was a compromise between the needs of bipedal locomotion and the need for a wider pelvic opening. The implication is that the female pelvis should be similar across the world. Researchers examine the size and shape of the birth canal of female individuals in the Goldman and Human Origin datasets. Contrary to the 'obstetrical dilemma,' the findings reveal that there is indeed significant geographical variation in size and shape of the female birth canal. Neutral evolutionary processes, particularly genetic drift, were suggested to be influential in female canal shape whereas the predicted effects of climate on canal diversity were only minimal.
Documents and Hypotheses Filed By: milagro.escobar  anj.droe