Has evolution had an effect on penis size?
Most of us prefer large penises, but does a larger penis hold any evolutionary superiority over a smaller penis?
I believe there are studies showing that men with larger penises have sex more often than men with smaller penises, which would lead me to believe that penises would naturally become larger as the years go by.
No.
Not significantly.
When any trait holds any kind of particular advantage, the pressure of selection will, over time, narrow the variety of that trait toward the optimal advantage.
For example, A very specific size and design of tail feathers on Peacocks is a significant advantage.
The result, nearly all peacocks have tail feathers of nearly identical configuration or design.
Or, say the horns on a ram.. they confer an advantage. The result, The relative size and form of Ram's horns is universally similar to a very high degree.
When any given trait confers no or nearly no evolutionary advantage, then what you will see is Genetic drift.
With no strong selection to weed out the "less advantageous" genes, ordinary mutation and reproductive variation will result in a Wide variety of genetic expressions.
that is, the less important a trait is for survival, the more variable that trait will appear thru any population.
For example... Lions are ALL tawny because Brown Lions would be at a significant disadvantage... thus nearly zero variation in color among Lions.
Whereas, in domestic cats color has little or no bearing whatsoever on survival... the result, Cats come in a wide range of colors.
The fact that male penis's range so widely, from 2 inches to 10 inches... a factor of 5... shows that penis size in itself can not confer any particular genetic advantage.
The size of a human penis is almost certainly driven by the size of the female vagina... which is driven by the size of the infants head.