How do YOU measure up?

[joegrundman]

Well, I won't make any claims about humans, but with other great apes, specifically our close relatives chimps and gorillas, there is an interesting fact.

Chimps have much greater penis size as proportion of body size than do gorillas.

And this is an evolutionarily determined feature related to sexual habits.

Both chimps and gorillas are social animals.

The alpha male gorilla has sole sexual rights to all females in the group, and this means that the requirements to gain sexual priority are physical strength and social intelligence in order to attain the number one spot in the group. Penis size is irrelevant, since once a gorilla has attained dominance, it is assured that it will reproduce and no other males in the group will. Hence physical strength and social skill will be selected for, but penis size will not.

Chimpanzees on the other hand have a different social structure. When a female is in heat, the alpha male is entitled to the first mating, but after that, all males in the clan get to mate with the female in order of social precedence.

Therefore the ability to deposit sperm deep leads to increased chance of fertilisation. Therefore, since penis size is genetically inheritable, amongst chimps penis size is selected for.

This explains why penis size in chimps is proportionally so much greater than for gorillas.

here's another interesting article explaining the function of the interesting head shape of the male human penis.

http://www.scientificamerican.com/ar...of-the-phallus