Friday, 17 June 2016

The Redemption of Michael Morwood and His Flores Hobbits

 About ten years ago, not long after I brought out a book on the peopling of the Americas called Bones, a great big controversy burst over the world of paleo-anthropology. It found its way to the front pages of newspapers, science magazines, and science television shows everywhere. An Australian archaeologist, Michael Morwood, his anthropological colleague Peter Brown, and their Indonesian colleague Sutkina, et al., published a jaw-dropping article that made the front cover of Nature, Britain's leading general science publication. In it they announced their discovery of tiny, wee human-like bones of creatures who had lived in the late Pleistocene (end of the Ice Age) in a cave called Liang Bua, on the island of Flores, Indonesia. Sutkina had unearthed them just days after Morwood left for home (Australia) at the end of the digging season.

In the giant cave's deep sediments, peeled back to reveal thousands of years of pre-history, Sutkina found a scatter of animal bones, some large, primitive stone tools, some small and sophisticated ones, along with an almost complete skeleton of what looked like a shrunken human, plus a few bones from five other individuals. The one almost complete skull found was extremely small: it had housed a brain about the size of a chimpanzee's. Peter Brown's analysis of these bones suggested that they represented  a previously unknown human-like species which he named Homo floresiensis

The editor of the Nature article made sure it got the attention of Fleet Street by calling these little people Hobbits. (He happened to be the author of a book on Hobbits). They were almost Hobbit-like in size, though no fur was found among their foot bones, and the Shire they inhabited was not exactly a peaceable kingdom. They had contended with shrunken elephants, extremely large and ferocious rat-like animals, and Komodo dragons big enough to scare the crap out of Gandalf the Grey.

The big question was: who were their ancestors? Homo erectus? Surely not. The skull was less than half the size of the average erectus adult. The arms weren't like erectus in form either, more like the Australopithicines (think Lucy) who had last roamed Africa more than a million years earlier.  The other bizarre finding was that these little 'people,' may have inhabited the island of Flores as recently as 18,000 years ago, long, long after science dogma insisted that only modern humans remained to triumph over the world and perhaps around the time the first modern humans arrived on the island. The fact that human-like creatures with such small brains could have found their way to Flores first was considered to be astounding. Flores had never been connected to mainland Asia, not even during the Ice Age when sea levels were much lower. It has always been surrounded by a very treacherous sea. So how and when had these primitive little people found their way there? By accident? Or were they smart enough to make some sort of boat?

Finding a new species of human-like creatures living side by side with modern people was the paleo-anthropological version of digging up the Grail. Thus, having the nerve to announce it without sufficient buy-in from other field leaders precipitated war.

The story caught my imagination because of the push back, the name calling, the bone stealing and the tub-thumping that ensued. It reminded me of what I'd found while researching Bones.  Early theories about who peopled the Americas had became immovable facts with little in the way of evidence to support them. The main theory about the origin of Native Americans did not even whisper about the possibility that ancient people used boats to get to either North or South America from the European side of the globe. Only one means and one point of entry was considered: by foot, over the Bering Land bridge and down through what was theorized to be an ice free corridor between the two glacial masses that covered North America at the height of the Ice Age. Those who ascribed to this theory/fact protected it for generations from all comers, using the institutions of science to enforce their views and to hold off findings that might contradict. And so it was with Homo floresiensis.

Within a matter of months after the publication, the bones found on Flores were taken away from their discoverers by the leading figure in Indonesian anthropological science, Teuku Jacob,a man with very narrow views, but real political power. He soon published the results of his own investigation, insisting that the remains represented not a new species but a diseased form of modern human available to be seen elsewhere on the island of Flores, suggesting that Morwood and Brown were both ignorant and sloppy in their work.  He got buy-in to his theory from others with bones to pick with Brown and Morwood, and especially from those who insisted modern humans arose only once, in Africa, and spread out from there, wiping out all earlier forms of humans in their path. It took a long time before the little people's bones were returned by Jacob and when they were, it became clear that they had been damaged in the process of study.

What was most familiar in this story was how quickly Morwood and Sutkina's find was incorporated by warring sides in the larger debate concerning how modern humans came to be the last of the Homo genus on the planet. One group, led by Chris Stringer at the Museum of Natural History in London, insisted that modern humans wiped out all the rest, our intelligence making it easy for us to out compete other humans, especially Neanderthals who, it was argued, we did away with over the course of a few thousand years as the ice age ended in Europe. Milford Wolpoff, an American scholar, insisted that we modern humans wiped no one out, we are instead the result of 'gene flow' between many branches of the Homo bush, by which he meant sex happened between modern humans and Neanderthals, Neanderthals and a new group just discovered called Dmanisi, etc.  Neanderthals didn't so much die off as become absorbed by us through interrelationships, is what Wolpoff's argument boiled down to. This view turned out to be correct. In Germany whole genome analysis of Neanderthal versus modern human remains made it clear that not only do modern humans have DNA markers seen in abundance in Neanderthals, but also show similar markers to another version of semi-modern humans, the Dmanisi of Eastern Europe. Gene flow turned out to be the correct way to think about how we became who we are.

I interviewed both Morwood and Brown shortly after their Nature publication. [For a longer version of their views at the time, please read the introduction to my last book, SMARTS.] Morwood explained to me that he had begun to investigate at Liang Bua after making a remarkable find in the 1990s in another Flores cave called Mata Menge which is about 75 kilometers away. He had gone to Mata Menge to follow up on the work of Dutch scholars who had dug there in 1970s and found what might have been extremely primitive stone tools dating back about 700,000 years. It was at first assumed that if these stones were tools, their makers must have been Homo erectus whose remains were first discovered in Indonesia at the end of the 19th century by a Dutch scholar named Eugene Dubois. Their remains were later found elsewhere in Asia dating back at least 400,000 years. Some Chinese scholars insist that Asian Homo erectus are the precursors of modern humans, in other words, that we did not arise in Africa, but out of Asia. Yes, there are political undercurrents to all of these arguments.

Morwood told me  that he would be returning to Mata Menge because he had a feeling he would perhaps find more remains of Homo floresiensis there.

Morwood died a few years ago. But his successors, a group led by a Dutch scholar named van den Bergh, have been hard at work at Mata Menge. They just published in Nature an article about the human-like remains they found at the site in 2014. These bones were hidden below a capping layer of volcanic ash dated to about 700,000 years before present. The remains are very few, just a mandible and a few teeth, no more. They are similar, but not identical, to the Hobbit's. They are quite a bit smaller. They could well represent a predecessor to Homo floresiensis but there are not enough remains to make that claim or refute it. The Liang Bua remains have since been re-dated to about 60,000 years before present, which makes the Mata Menge bones very distant from them in time. However, they were found amid a scatter of the same kinds of animal remains, and the same kind of primitive stone tools, as were found in Liang Bua.

Morwood's name is on this Nature paper though he did not write it. That is what redemption looks like in paleo-anthropology. It's too bad he didn't live to see it.

If you care to read a much more expert evaluation of the nature of these finds and their intellectual context, please read John Hawks blog where you will also find a link to the Nature paper. John Hawks, it should be mentioned, was a doctoral student of Milford Wolpoff mentioned above.

No comments:

Post a Comment