Return of the Prodigal Bones

The Sydney Morning Herald reports today that the bones of Homo floresiensis, aka the Hobbits, have at last been returned to the team that originally discovered them.

The team, made up of Indonesian and Australian scientists, discovered the bones on the Indonesian island of Flores. Last October they declared that they had found a new species of diminutive, small-brained hominid that existed just 12,000 years ago. Then, in November, the bones wound up in the hands (or, rather, the locked safe) of the Indonesian paleoanthropologist Teuku Jacob. Jacob claims that a member of the Hobbit team asked him to look at the bones. Members of the team see things a bit differently: they accuse him of poaching. In response, Jacob has called them a bunch of would-be conquistadors. (I have some more background in my previous Hobbit posts.) Jacob promised to return the fossils by the end of 2004, but it is only now, two months later, that he’s made good.

But I’ll bet that we’ll be hearing again about this conflict before long.

Jacob has scoffed at the notion that the Hobbits are a separate species, saying instead that they were pygmy humans. He thinks the team that discovered the bones was fooled by the skull they unearthed. Its seemingly primitive condition, he claims, is the result of a birth defect called microcephaly.

This interpretation would, I imagine, please the minority of paleoanthropologists who are unhappy with the current consensus about modern human origins. Most researchers agree that all living humans descend from a small group of Africans who lived less than 200,000 years ago. Other hominids–Neanderthals, Homo erectus (and possibly Homo floresiensis)–became extinct. They may have mated with members of our own species when Homo sapiens came out of Africa about 50,000 years ago, but they’ve left behind little or now DNA in living humans.

But some researchers have stuck to an older hypothesis, that living humans have multi-regional roots that include Neanderthal and Homo erectus ancestors. In fact, they see no need to split up hominids of the past one million years into separate species.

It was thus not a complete surprise to learn last week that Teuku Jacob had arranged for two multiregionalists, Alan Thorne and Maciej Henneberg to examine the Homo floresiensis bones. Publicity may have been one motivation–a 60 Minutes crew was apparently filming the proceedings–but something very significant happened along the way. Two grams of the fossil material was extracted and sent to Germany to look for DNA.

As I’ve mentioned before, finding Hobbit DNA is the best way to test the hypothesis that these fossils belong to another species. If the Australians are right, its DNA should be only remotely similar to the DNA of all living humans. If Jacob is right, the DNA should resemble the DNA of living Southeast Asians more than other humans.

But any results that come from the DNA Jacob and company have extracted will probably be viewed with a lot of skepticism. It is very easy for fossils to become contaminated with the DNA of living humans once they are unearthed, and it very difficult to distinguish between contamination and any ancient DNA the fossils might contain. Jacob didn’t help matters when he "borrowed" the bones; apparently they were simply stuffed into a leather bag and brought to him. And his new colleague, Alan Thorne, has already drawn some intense criticism for not being careful enough about DNA contamination when he claimed to have found ancient genetic material from the fossils of early Australians.

For the time being the Australian-Indonesian team may not be able to help matters much. Reports indicate the they hadn’t extracted DNA from the fossils before the fossils were extracted from them. Still, the discovery has focused the world’s attention on the caves of Flores and nearby islands, which may translate into many hours of digging, which may in turn translate into a lot of new fossils in years to come. Here’s hoping that they aren’t yanked around so pointlessly.