Imagine a world where the boundaries between “fish” and “not-fish” blur, where the ancestors of birds and mammals once swam ...

Complex neural circuits likely arose independently in birds and mammals, suggesting that vertebrates evolved intelligence ...

If Blob had been born with a spine, or backbone, he would have been a vertebrate. If we give Blob some legs and a head then he can start to move about. There are lots of vertebrates in the animal ...

Among them were the chordates, to which vertebrates (animals with backbones) such as humans belong. What sparked this biological bonanza isn't clear. It may be that oxygen in the atmosphere ...