Females protect offspring from infanticide by forcing males to compete through sperm instead of violence
13 Nov 2014Latest research shows the females of some mammal species will have many mates to ensure unclear paternity, so that males can’t resort to killing their rival’s offspring for fear of killing their own. This forces males to evolve to compete through sperm quantity, leading to ever-larger testicles. Scientists find that as testis size increases, infanticide disappears.