Reply to Underdown and Oppenheimer: Roles of selection, plasticity, and genetics in the integration of human pelvis shape and head size

In our paper (1) we report on a previously unknown association between human pelvis shape, head size, and stature that appears to ameliorate—but in no way resolve—the obstetric dilemma. In an interesting response to this article, Underdown and Oppenheimer (2) emphasize that “one must explicitly consider whether the suggested relationship is an evolutionary-selective phenomenon or an analytic artifact produced by combining multiple anatomically related variables (each of which potentially underwent differential patterns of selection) or plasticity in the individual.” Independent selection of pelvis shape, stature, and head size would produce covariation of average population phenotypes across evolutionary time, but not of individual phenotypes … [↵][1]1To whom correspondence should be addressed. Email: b.fischer{at}univie.ac.at. [1]: #xref-corresp-1-1