Which animals evolved first?

摘要

SPONGE or jelly? Though it sounds like a choice between desserts, it turns out that either sponges or comb jellies are the key to understanding the early evolution of animals and when the first brains evolved. That is because one of them was the first animal group still alive today to split from other animals and begin evolving separately -but it has long been unclear which. A new analysis points the finger at jellies. The study has been praised by scientists on both sides of the debate because it brings clarity to a confused area, but it isn't being interpreted as the definitive answer.