The male Y chromosome in humans is evolving faster than the X. Scientists have now discovered the same trend in six species of primate.

Our distant fish ancestors had gills, so why don't humans?

Using a new technique, scientists created genetic blueprints for kangaroos, penguins, sharks and more.

It isn't true that we can't smell ourselves, although we do become habituated to our own scent.

Whether arms or legs are more important depends on the species and the environment.

Researchers now understand why there is an uneven distribution of animal species on either side of the mysterious boundary, known as the Wallace Line.

Something unique does seem to have taken place during this time when so many animal groups first appeared, but it's not an open-and-shut case.

The bulbous-eyed mudskipper could offer key clues about how our fishy ancestors first made the leap to land.

Leading theories suggest that the first energy used by life was either from the sun or from geothermal heat and chemistry at the bottom of the ocean.

Most biologists will answer confidently when asked "which came first, the chicken or the egg?" but the answer may depend on what type of egg you're talking about.