Mapping mollusks
What do a typical garden snail and an octopus have in common, besides the occasional appearance on the plates of adventurous diners? More than you may realize. Both are mollusks, a group of animals that includes everything from slugs to squids, and one that has for years confounded efforts to describe how its varied members evolved. But now, with the help of the latest genetic tools, researchers at Harvard and collaborating institutions have completed the most comprehensive evolutionary tree ever produced for mollusks. Described in the Nov. 2 issue of Nature, the work also serves as a proof-of-concept, demonstrating the power of genomic techniques to answer difficult evolutionary questions. “I think this is a big step toward understanding the tree of life,” said Gonzalo Giribet, professor of organismic and evolutionary biology, and one of three lead authors of the paper. “One reason we chose mollusks was because it has been one of...