Almost a third of Laysan albatross couples are female-female pairs that build nests and rear young together. They are more reproductively successful than unpaired females. Photograph: Eric VanderWerf/Trends in Ecology & Evolution
Birds do it. Bees probably do it. No one's sure whether educated fleas do it. What they do is have same-sex relationships and, in a new review of published research on the subject, biologists have started to consider what it might mean for the evolution of the animals in question.
same-sex relationships were a universal phenomenon in the
animal kingdom, seen in everything from worms
bonobos, dolphins, penguins and fruit flies
engage in same-sex interactions to facilitate group bonding, or female Laysan albatross that can remain pair-bonded for life and cooperatively rear young
the relationships shape the course of evolution
same-sex behaviors might act as selective forces in and of themselves
clipped from: www.guardian.co.uk