by Tauana Junqueira Cunha If we could travel back in time 540 million years, what would the first animals look like? This is one of the longstanding questions scientists aim to answer in the study of how animals evolved and became distinct from their unicellular relatives. To answer it, we need to know how modern animals are related to each other, what order they appeared … Continue reading Were the First Animals Sponge-Like?: Complexity in the animal tree of life