The evolution of some of the earliest complex animals on our planet may have been spurred on by other, simpler early animals. These simple marine animals first evolved around 560 million years ago and ...

Why did humans take over the world while our closest relatives, the Neanderthals, became extinct? It's possible we were just smarter, but there's surprisingly little evidence that's true.

Oxygen levels in the Earth's atmosphere are likely to have 'fluctuated wildly' one billion years ago, creating conditions that could have accelerated?the development of early animal life, according to ...

Over the last half a billion years, the ocean has mostly been full of oxygen and teeming with animal life. But earlier, before animals had evolved, oxygen was harder to come by. Now a new study led by ...