Humans have had a long history. 3.8 million years in the making, to be precise. From the primordial puddle to the modern day, here's how humans have evolved. The following is a review of the life ...

This photo shows a fossilized skull of Acanthostega, one of the first land vertebrates. Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert!