Betti et al. (2013)
showed that there are at least regional dependencies of genetic
distances estimated from pelvic morphology and geographic distances
(a proxy for overall genetic distance). Foster and Collard
(2013) argued that the relationship between body mass and latitude
did not hold up except when extremes of latitude in the
Northern Hemisphere were included in their analysis. This suggests
that selection is appreciably strong only at the extremes of latitude
(and, ostensibly, climatic factors) (as also argued using empirical
trait distributions by Auerbach, 2007), and that other forces of
evolution and environment predominate in the remainder of the
comparisons.