In marine mammals’ battle of the sexes, vaginal folds can make the difference
Patricia Brennan has made a splash with her studies of genitalia and fit
The battle of the sexes, at least among certain ocean mammals, may come down to well-placed skin folds, suggests research by Patricia Brennan, an evolutionary biologist at Mount Holyoke College in South Hadley, Mass., and colleagues.
In some species, enhanced male-female genital fit has evolved over time in ways that make mating easier. This is an example of what scientists call congruent evolution. In other species, genital anatomy reflects a battle, as shape and form change over time to give one sex an edge in control of fertilization. Fittingly, this is called antagonistic evolution.