The comb jelly Mnemiopsis leidyiBRUNO VELLUTINISponges have been generally considered our most ancient animal relatives. But that title may actually belong to members of the anatomically more complex phylum Ctenophora, or comb jellies, according to a report published today (December 12) in Science. This family tree reshuffle has come about thanks to the whole-genome sequencing of the comb jelly Mnemiopsis leidyi.
“It’s very exciting because there’s been a lot of debate about early animal evolution,” said John Finnerty, a professor of biology at Boston University, who was not involved in the study. Part of the reason for the debate was the lack of a whole genome sequence from a comb jelly. “The major early animal lineages had all been represented by at least one species with a sequenced genome with the exception of the Ctenophores,” Finnerty said, “so this really was a key piece of missing evidence.”
As their name implies, comb jellies are gelatinous animals with combs—bands of cilia running along their bodies that enable them to swim about in the sea. Based on their morphology, comb jellies had traditionally been considered close relatives of ...
