In most animals, females are larger than males, but in most mammals, males are larger than females.
A new study examined the potential drivers of these differences- casting doubt on the theory that only sexual selection is at play in mammals–that males compete to mate with females, and bigger males are more likely to win.
The study found that alongside sexual selection, natural selection may be an evolutionary driver of sexual size differences in mammals.
- Sexual size dimorphism and sexual selection in primates. DOI: 10.1111/mam.12191