Subsize humans living in caves on a remote, forgotten Indonesian island, hunting dwarf elephants and giant rats? Sounds like a cheesy sci-fi flick, but in late October Indonesian and Australian scientists reported finding evidence of just such an unknown species.
Researchers unearthed a partial, nonfossilized skeleton of what appears to be a 30-year-old woman in a limestone cave on the island of Flores, 370 miles east of Java. In life, she stood barely three feet tall and possessed a brain roughly one-third the size of a modern human’s. She was not alone; bones and teeth of as many as seven adults were recovered from the same site, along with animal bones and much older stone tools. The big surprise came when scientists determined the age of the remains: The bones of these diminutive people, who appear primitive alongside Homo sapiens, date to only 18,000 years ago, when humans also walked the earth.
These small people are not our ancestors but rather our evolutionary cousins. Dubbed Homo floresiensis, the hominid appears to have walked upright and used tools and fire. The lead researcher, paleoanthropologist Peter Brown of the University of New England in Australia, says his jaw dropped when he realized what he was looking at.
How long H. floresiensis persisted, or whether the species ever came face to face with H. sapiens, as did Neanderthals in Europe, is unknown, but local folktales suggest that little people were living in caves on some Indonesian islands when the first Dutch explorers arrived in the 16th century. Another open question is how these people first reached Flores however long ago.
The small stature of H. floresiensis is a clear demonstration that hominids are not exempt from the laws of evolution and specifically from the “island rule,” which posits that a combination of selective forces—geographic and temporal isolation, scarce resources, the absence of predators—will occasionally result in the evolutionary development of giant and dwarf species. Elsewhere in the Indonesian archipelago, a similar array of pressures conspired to produce huge lizards like the Komodo dragons, giant rats, and tiny elephants.
On Flores, “hominids are following the same evolutionary and ecological rules as other mammals,” says Tim White, a paleoanthropologist at the University of California at Berkeley who consulted on the research. “Darwin would have been delighted.”