More evidence for a previously unknown species of human

SVANTE PAABO, the DNA palaeontologist whose work provided the inspiration for “Jurassic Park”, has produced a nice Christmas present for students of human evolution. He and his colleagues have confirmed, using the creature’s whole genome, that a fossil finger bone which is at least 30,000 years old, and which was found in a cave in the Altai mountains of Siberia, comes from a previously unknown human species. That was all but certain from their previous study of the creature’s mitochondrial DNA (an abundant form of the molecule found in cells’ powerpacks), released in March. The latest analysis, published in Nature on December 23rd, removes any doubt—and adds a tooth to the meagre stock of evidence from the new species that modern science is able to examine.

This discovery is extraordinary on many levels. Perhaps the most important is that one small group of modern humans who live far away from Siberia—the Melanesian islanders of the Pacific Ocean—have picked up a block of genes from the newly discovered species on their (or, rather, their ancestors’) travels. Genetic evidence of the Melanesians’ journey from the African cradle of Homo sapiens, which started (like that of all non-African people) about 60,000 years ago when a band of adventurers crossed the straits of Bab el Mandeb, from modern Djibouti to modern Yemen, suggests they then continued along the south coast of Asia, never going far inland. For the necessary interbreeding to have happened, Dr Paabo’s new species would thus have to have been spread over a vast area of Asia. Yet it has left no previously identified traces. …