To explore that question and others, a group of biologists decided to tackle an entire comb jelly genome.
According to one mathematical model that compared thousands of portions of the comb jelly's genome to those of other organisms, comb jellies belong at the base of the animal tree of life.
Baxevanis' team scanned the comb jelly genome for some of the most widespread and fundamental gene families in the animal kingdom.
More support for the dramatic repositioning of the comb jelly emerged at the San Francisco meeting, where in addition to Baxevanis' talk there were 13 other presentations and posters related to the jelly genomes.
Like Baxevanis, Moroz and his colleagues found a slew of genetic differences between the gooseberry comb jelly and the other types of animals they compared it with.
If the comb jelly lineage branches off at the bottom of the tree, parsimony suggests that the comb jellies independently gained complex features.
The fact that the comb jelly lineage landed in different places depending on the analyses Baxevanis' team ran highlights the difficulty of reconstructing the single, true tree of life.
Perhaps the proteins that help a comb jelly to regenerate its brain, nerves and muscles could reveal a potential to do the same in humans, he says.
leidyi comb jelly's annotated genome online, and while both teams have revealed their findings at meetings neither has published its magnum opus: the definitive comb jelly genome manuscript announcing its more ancient origin and its independent evolution of complexity.
If more biologists would only devote their attention to the comb jelly, he argues, they'd learn how innovative evolution can be.
Based on DNA sequences, scientists say the comb jelly lineage may have branched off before the lineages of all other living animals and that the odd creatures evolved their central nervous system and muscles independently.
Caption: The sea gooseberry comb jelly Pleurobrachia bachei (left) snags prey with its long tentacles, while Mnemiopsis leidyi (right) employs mucus-covered lobes.