Adult male humans generally have deeper voices than do adult female humans, which is the direct result of higher levels of testosterone causing growth of the larynx. If the fossil records of apes and humans alike show a trend toward decreasing larynx size in adult females and increasing larynx size in adult males, then
A) sexual dimorphism was developing over time in these species.
B) intrasexual selection seems to have occurred.
C) stabilizing selection was occurring in these species concerning larynx size.
D) selection was acting more directly upon genotype than upon phenotype.
Female reproductive structure and function in humans.
Muscle male/female
Genetic differences between humans, Neadertals, and chimps.
Adult Blood Pressure Guidelines
Female athletes
Mutations in posterior Hox genes (HOXD13 in this case) in humans