Comb Jelly Was Our First Ancestor

Say hello to the comb jelly, your first ancestor according to a new study. 

What were the first animals--and thus the first human ancestors? Scientists have long thought sponges are all the way at the bottom of the animal tree. (Sponges may not look much like animals, but they are: they do things like produce sperm and eggs, and sponge larvae can swim.) Now, a new study published in Science claims that before sponges hit the evolution scene, Ctenophora, or comb jellies, had evolved.

In the study, a team of researchers from the National Human Genome Research Institute created the first complete genome sequence of a comb jelly. When the researchers took this new genome sequence and entered it into software that finds evolutionary relationships among organisms, what they found surprised them: the comb jelly didn't sit in the middle of an animal group, but most likely was at the base. It was the first animal.