
Gaining Ground, Second Edition
Around 370 million years ago, a distant relative of a modern lungfish began a most extraordinary adventure—emerging from the water and laying claim to the land. Over the next 70 million years, this tentative beachhead had developed into a worldwide colonization by ever-increasing varieties of four-limbed creatures known as tetrapods, the ancestors of all vertebrate life on land. This new editio...
Around 370 million years ago, a distant relative of a modern lungfish began a most extraordinary adventure—emerging from the water and laying claim to the land. Over the next 70 million years, this tentative beachhead had developed into a worldwide colonization by ever-increasing varieties of four-limbed creatures known as tetrapods, the ancestors of all vertebrate life on land. This new editio...