Comb Jelly Reveals New Secrets of Animal Evolution

For more than a century, scientists believed that complex cell types, such as neurons and muscles, evolved only once. The simple animals that lack these cell types branched off from the rest of the animals on the evolutionary tree. Now, though, a comb jelly has challenged this belief and has shown that these complex cells were gained and lost several times over the course of evolution.

The comb jelly in question is called Mnemiopsis leidyi, which is native to the coastal waters of the western Atlantic Ocean. In order to find a little bit more about this species, though, the researchers used whole-genome sequencing. The scientists compared the order of the chemical bases of DNA that comprise the organism's genome.

Source: Here