Attention men: In the last second your bodies each produced around 1,500 sperm cells.

Human sperm stained for semen quality testing. Via Wikipedia

The great disparity between the production of sex cells in men and women has an evolutionary basis. Women have a great evolutionary investment in each of their offspring. With each fertilized egg they must go through the process of conception, fetal maturation, nutrient production, child rearing, etc., during which time they are unable to have additional children to advance their genes. In comparison, a man’s involvement can successfully end after insemination and begin again almost immediately with another female.

A man’s sex cells do not require much investment, as it is to his evolutionary benefit to inseminate as frequently as possible, and are therefore copiously produced.

[Via National Geographic]