Friday, July 14, 2006

Last night's lecture

The first thing I noticed about Peter Brown is that he seemed to be on the verge of keeling over with exhaustion. This was a man who has been on the public lecture circuit a long time. It also showed at a point in the presentation when he knocked a key that made his computer desktop visible, where you could see five different clocks with local times all around the world, and folder after folder labeled “USA lecture”, “Australian lecture”, and so on.

Despite the tiredness, he was an engaging speaker. I didn’t think so for the first five minutes, when his credentials, background, etc was delivered in a monotone that was completely oblivious of sentence transitions. I have no idea when the man breathed, because he didn’t seem to leave himself any time for it.

But then he told the story of the discovery as a narrative, and the suspense at each point in the story just about stopped me from breathing. When he got to the point where he realised what they had found, I felt shivers prickling up and down my spine. It seemed that Brown himself got a little emotional in the retelling, too. But after all, imagine what a life-changing event it must have been: One minute you are looking at a skeleton that just doesn’t make sense: it looks like something from 2 million years ago, but you know it is only 15000 years old. The next minute your measurements confirm that it isn’t homo sapiens, it isn’t homo erectus, and to be honest, it just isn’t homo anything.

Brown said quite categorically that if the team had had access to the full evidence (the arms of the first individual, and the other skeletons) when they published the first article, they would never have classified the skeleton as homo. The first one they found was ‘the basketball player’ of the group, and her arms were bent beneath her, so not uncovered and measured until much later (when it was found that the skeleton had the same arm-to-leg ratio as a gorilla -- nothing like any of the homo family at all).*

Peter Brown’s conclusion, which he claims is shared by the rest of the team and everyone who has looked at the evidence themselves, is that these came out of Africa around 3 million years ago, and that they are related to australopithecines. They obviously made stone tools, but seemed to have had no symbolic culture (art, pottery, etc), and probably no language. This first attempt at an exodus from Africa was generally unsuccessful, but an enclave of these things survived on Flores, and possibly other Indonesian islands, until they were killed 15000 years ago by a volcanic eruption.

I thought he convincingly demonstrated that homo floresiensis is not related to any of the other hominid groups, and that the most similar family is australopithecines. He didn’t seem to have much evidence that they had reached Flores so early, though, or even that they left Africa 3 million years ago. He only had evidence that they had been in that particular location for the 3000 years preceding their extinction, and apart from a few tools found in Pakistan and China, there is not much evidence of such an early wave of migration from Africa.

I would have thought that if another genus of hominid had been hanging out in the region for 3 million years, we would have found more trace. But then, I would have thought if strange hobbit hominids had been hanging out in Indonesia 15000 years ago, we would have found them before now, too, yet we didn’t. Brown seemed certain that more skeletons and other archeological evidence will be found in the region now that they know what to look for.

I would say that the biggest point that struck me from his lecture, though, was how much the media suck.

To start with just about every newspaper and magazine who ran a piece on the “hobbit” skeletons created an artist’s impression of it, and every one of them sent him the picture to comment on and correct, then systematically ignored every flaw he pointed out. All of them gave it an improbable nose. Not one of them got the leg-to-arm ratio even vaguely right.

Secondly, the “controversy” surrounding the skeletons was entirely media-generated. The public was given the idea that there are three competing theories: that they are pathological human skeletons, that they are homo floresiensis, and that they are the products of island dwarfism. In actual fact, according to Brown, all experts in the field who have published in peer-reviewed journals on the subject, all of the 12 (12!) reviewers of the first article, and everyone in the field who has read the papers agree that these are not pathological specimens. Brown pointed out that there was originally a whole section in the first article devoted to refuting this idea, but that the reviewers were unanimous that this was unnecessary because it was “so bleeding obvious”. The only person who has claimed the pathology explanation was someone a news team sought out after the discovery was announced in order to find an opposing viewpoint. The guy hadn’t read the article or seen any of the evidence, and said it must be either a pathological human, a mistake, or a hoax -- which is precisely what ALL of Peter Brown’s team believed until they had seen it, because the reality was just so unexpected. But the media made it sound as though both this random guy who hadn’t seen the skeletons or the evidence, and Peter Brown, who had worked on the skeleton himself and had peer reviewed publications on it, had equally valid and well justified viewpoints.

As for the idea that it was island dwarfism, this is not someone else’s viewpoint, but rather the “most likely scenario” envisaged by Peter Brown and his team when they published the first article. This was because they had not yet seen the arms of the skeleton (or any of the other 7 or 9 skeletons), since these were buried underneath the rest of the body. He said that once they had seen the ratio of the arms to the legs, they knew that it couldn’t possibly be dwarfism, but had to be something completely new. So no one believes in the “island dwarfism” explanation now, but the media continues to portray it as a competing theory.

There was a question session at the end, which was a demonstration of how to be diplomatic. Example:

“Are the excavations still ongoing?”
“Yes, elsewhere on the island, but not in Liang Bua.”
“Is that political?”
“Yes. Next question, please.”

And finally, I have to mention the image that stuck with me most from the talk. This was from a moment near the start when Brown was talking about how humans (and presumably also these things) traveled from the mainland to islands like Flores, and how it was a bit of a mystery that they made it, considering how strong the currents are. Then, after a moment’s thought, “Of course, elephants managed it, since that’s where the ancestors of the Flores ‘bonsai elephants’ came from. But elephants are very buoyant.”


* This wasn’t his only evidence for the classification of these skeletons, though. He also systematically showed that they differ from modern humans and homo erectus in premolar shape, brow ridge, brain size, chin (lack of), shape of base of skull, and size of teeth relative to body size. He showed that there is no pathology that would cause the arm-to-leg ratio, the brow ridges, and the lack of chin. The head-to-body ratio is also different from pygmy humans (who still have a ‘normal’ skull size, while these things have the brain size of a chimpanzee).


bridgett said...

Cool! I missed Brown when he came to NYC (the closest he got to my hometown), but even the "academically responsible" New York Times had the same sort of coverage. It was impossible to tell what the man had actually said.

Thanks for delurking over at TCP.

Honeybee said...

This sounds like an excellent talk. Thanks for giving us the rundown!

I think bonsai elephants is just a hilarious concept. "If we trim just a leeeetle more off of the ear, it will be perfect!

Jesse said...

I feel sorry for the guy. Atleast he seems organized....

Grace said...

That is really fascinating. I saw the Nat Geo documentary, which made much of the "pathological" argument, and then conclusively trashed it, to the extent that I felt a bit sorry for the guy who was propounding it. I feel even MORE sorry for him now!

And I didn't realise that subsequent excavation had shown the skeletons to be unlike homonids. That certainly raises a lot of questions, as you say!

As I understand it, paleoanthropology is such a speculative field because the physical evidence is so incomplete, and it's often impossible to judge between competing hypotheses on the evidence alone. Brown and his team were very lucky to find relatively complete skeletons. [remember "Peking Man"? that was a single skull fragment!]

StyleyGeek said...

Yes, Brown mentioned that that was one of the most exciting things about it: that they had found several complete skeletons, and bits from between 7 and 9 different individuals, so the evidence was really very clear.

I love the concept of bonsai elephants too!