"Researchers at the University of California, Riverside, have found the oldest clue yet of animal life, dating back at least 100 million years before the famous Cambrian explosion of animal fossils. The study, led by Gordon Love, a professor in UCR’s Department of Earth Sciences, was published today in Nature Ecology & Evolution. The first...

"Hundreds of millions of years before there was a chicken or an egg to debate, the first complex animals were evolving in parallel with Earth’s rising oxygen levels. But what came first — animals or oxygen? That question is the central theme of a special issue of Emerging Topics in Life Sciences published Sept. 28...