Evolutionary biologists have re-written the animal tree of life. A new study uses new genomics tools to answer old questions about animal evolution — and offers up a few surprises among the branches. The study involved 40 million base pairs of new DNA data taken from 29 animal species. It settles some long-standing debates about the relationships between major groups of animals and offers up a few surprises. The big shocker: Comb jellyfish — common and extremely fragile jellies with well-developed tissues — appear to have diverged from other animals even before the lowly sponge, which has no tissue to speak of. This finding calls into question the very root of the animal tree of life, which traditionally placed sponges at the base.