Sponges: Oldest Creatures in the Sea?
Season 8 Episode 1 | 26m 43s | Video has closed captioning.
Until recently there was scientific consensus that sponges were the first animals to branch off the “Animal Tree of Life,” a kind of family tree for all living and extinct animals on earth. But recent DNA research has cast doubt on that theory, with some scientists suggesting that ctenophores, also known as comb jellies, are an older lineage.
Problems Playing Video? | Closed Captioning