Scientists explore the evolution of animal homosexuality... and its correlate in humans

Scientists explore the evolution of animal homosexuality... and its correlate in humans. Juanita Bawagan, Imperial College London, May 2, 2019. https://phys.org/news/2019-05-scientists-explore-evolution-animal-homosexuality.html

Imperial researchers are using a new approach to understand why same-sex behaviour is so common across the animal kingdom.

In 1910, a team of scientists set off on the Terra Nova Expedition to explore Antarctica. Among them was George Murray Levick, a zoologist and photographer who would be the first researcher to study the world's largest Adélie penguin colony. He chronicled the animals' daily activities in great detail.

In his notebooks, he described their sexual behaviour, including sex between male birds. However, none of these notes would appear in Levick's published papers. Concerned by the graphic content, he only printed 100 copies of Sexual Habits of the Adélie Penguin to circulate privately. The last remaining copy was recently unearthed providing valuable insights into animal homosexuality research.

But forays into animal homosexuality research long predate Levick, with observations published as far back as the 1700s and 1800s. More than 200 years later, research has moved past some of the taboos those early researchers faced and shown that homosexuality is much more common than previously thought.

Same-sex behaviour ranging from co-parenting to sex has been observed in over 1,000 species with likely many more as researchers begin to look for the behaviour explicitly. Homosexuality is widespread, with bisexuality even more prevalent across species.

Researchers are now going beyond just observing it though, with researchers at Imperial leading the way in unravelling how, and why, homosexuality is found across nature.

[Many more details at the link above]