Sign up for CNN’s Wonder Theory science newsletter. Explore the universe with news on fascinating discoveries, scientific advancements and more. Same-sex sexual ...

Source: Shark Bay Research Program, used with permission. Species across the animal kingdom play, suggesting the behavior has benefits. Scientists have long hypothesized a link between juvenile social ...

It can be hard to know if someone is really into you. Sometimes, you get hints — a certain look or smile, a nervous blush or flirtation. Giraffes get none of that. They have no set breeding season.

An international research team, including scientists from the Max Planck Institute for Evolutionary Anthropology in Leipzig, ...

Breakthroughs, discoveries, and DIY tips sent every weekday. Terms of Service and Privacy Policy. Male Indo-Pacific bottlenose dolphins form particularly tight groups ...

Jackson Clive received funding for this work from the UK Natural Environment Research Council, the American Institute of Bisexuality and the Genetics Society. Ewan Flintham receives funding from the ...