Songwriter Randy Newman once sang, "short people got no reason to live." But once upon a time, on an isolated island in the Java sea, short people not only lived--they dominated the food chain. Standing no more than three and a half feet tall, these human ancestors hunted giant rats, lumbering lizards, and miniature elephants.
It sounds a bit like a fairy tale, but it's true. Excavations on the island of Flores uncovered the remains of a race of tiny human ancestors. Homo floresiensis, as the newly discovered species has been named, apparently lived up until thirteen thousand years ago. This means they overlapped with modern humans.
So how and why did these people get so small? Scientists suspect that it's due to the fact that this race of Tiny Tims lived on an isolated island with limited resources. Take the case of the miniature elephants that are known to have once roamed the island. When elephants first came to the island either by swimming or some kind of natural land raft, they were probably close to full size. But since there wasn't much to eat, over time smaller elephants lived longer and fared better. The smaller the elephant, the less it had to eat to stay strong and healthy.
Scientists call this the "island rule," and it could apply to humans as well as animals. Given the island's sparse food supply, it makes sense that the early humans living there would have evolved a body size requiring less food to survive. So bigger isn't always better. In the case of homo floresiensis, at least, getting smaller was the way to go.