From National Geographic: New Giant Clam Found; May Have Fed Early Humans.

Genetic analysis has helped identify a new giant clam species in the Red Sea, a new study says.

The mollusk may hold clues to how and why humans migrated out of Africa more than a hundred thousand years ago.

The apparent near collapse of the species around that time likely points to overharvesting by early hunter-gatherers, says the study, published this week in the journal Current Biology.

Living specimens of the shallow-water species today are scarce. Researchers have located only 13 along the Jordanian Rea Sea coast, though the species appears to have been the dominant giant clam in ancient times.

The findings feed speculation that modern humans migrating out of Africa into the Red Sea region 110,000 years ago were motivated in part by disappearing seafood — perhaps the earliest example of marine overharvesting — the study said. [continue]