NEW YORK (AP) — Sponges are getting squeezed out of a distinctive role in evolution. A new study says they don't represent the oldest branch of the animal family tree after all.
The DNA research gives the spot instead to comb jellies, a group of gelatinous marine animals with names like the sea walnut and the sea gooseberry. The study says they belong to the first branch of the evolutionary tree to split away from all other animals more than half a billion years ago.
The evidence comes from deciphering the first complete genetic code from a member of this group. The results were reported online Thursday in the journal Science.