Were animal ancestors bisexual?
The paradox of same-sex relations in animals and humans has long confounded evolutionary scientists because it produces no offspring and, by their reasoning, should thus have been snuffed out through the laws of natural selection.
Yet, same-sex behaviour has been identified among more than a thousand animal species, from variegated sea urchins (Lytechinus variegatus) and molluscs to bonin flying foxes (Pteropus pselaphon), snow geese (Anser caerulescens) and domestic cows (Bos taurus).
Published by Cosmos.
