Some male animals may evolve weak immune responses so they can give their mates diseases.
Newly-discovered fossil deposit contains more than 50 unknown species from the Cambrian Explosion, when most complex body plans appeared.
Indoor temperature and moisture in the U.S. is closer to climates in Africa than to anywhere else on Earth.
When the foraging sea mammals crack shells to collect food, they produce distinctive evidence.
New research suggests the ancestors of reptiles, birds and mammals might have walked more efficiently on land than previously thought.
Long penises may allow hermit crabs to stay in their shells during sex, reducing the risk of shells being stolen.
Two well-preserved fossils found in China were covered in both furlike pycnofibers and featherlike features.