sperm

ulatory sexual selection—the competition among sperm from different males to fertilize a female’s eggs. Unlike pre-mating competition such as fighting or displays, sperm wars occur inside the female reproductive tract, where millions of sper

tion as a Sperm Quality Regulator Regular masturbation can help regulate sperm quality by promoting the turnover of sperm cells. By ejaculating periodically, older sperm—which might have reduced motility or DN