Question

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) the ʺgood genesʺ hypothesis was refuted by these data.
D) stabilizing selection was occurring in these species concerning larynx size.
E) selection was acting more directly upon genotype than upon phenotype.

Answer 1

A

Explanation:

Testosterone is only found in males and absent in female.

Testosterone is a sex hormone in males which helps in development in primary s organs, sex accessory organs and many other organs.

Testosterone causing growth of the larynx in males only because in females this hormone is absent so sexual dimorphism was developing over time in these species.

Due to increase in growth of the larynx in males, result as adult male humans generally have large larynx and deeper voices than do adult female humans.