Hobbits

Dean Falk is one of my closest friends down here at Florida State University. She is a paleoanthropologist, a student of human origins, and her specialty is the brain. She has spent much of her life with upended skulls, filling them with rubber and then peeling it off. Obviously the grey matter is long gone, but you can tell a huge amount about the brain by studying the bumps and fissures and so forth that are revealed by the inside of the skull. More recently, she has turned high tech, and a lot of the work done now is based on magnetic resonance imaging, a method of seeing the inside of things without actually having to disturb them at all.

In 2003 a group of Australian researchers working on the island of Flores in the Indonesian archipelago astonished the world by announcing that they had found the skeletal remains of little human-like creatures, about 3’ 6” tall and with very small brains, somewhat less than 400 cc.  To put matters in perspective, this is on the small (brain) size for chimpanzees, about a third the size of our brain, and probably even a bit less than Australopithecus afarensis, the most famous example of which is Lucy, believed to have lived a bit more than three million years ago and an inhabitant of East Africa.

It was pretty obvious that this was not a regular human being, and so it was given its own scientific name, Homo floresiensis.  This means that it is different from us, Homo sapiens, but not that different, because we are all in the same genus (Homo).  The thinking was that Homo floresiensis, naturally at once nicknamed the hobbit, was descended from one of the species ancestral to us too, Homo erectus. There is nothing very odd about that. Evolution happens. What is odd is that the evidence points to the hobbit as having lived pretty recently — as recently as 13,000 or 14, 000 years ago. If this is so, then it seems clear that for most of the span of Homo sapiens (about half a million years ago, give or take) we were not alone. Other members of our genus flourished on this earth.

Dean Falk was called in to do the work on the brain and this she did. In her mind, there was (and still is) absolutely no doubt that the hobbit is something new.  In fact, I can remember her confiding to me shortly after she started work that she suspected that the hobbit might be something even bigger than first supposed. She thought there was a distinct possibility that it was not part of our genus but had gone its own way back when we were all australopithecines. Something even more striking than expected.

As you might imagine, not everyone was convinced. One might almost say that in science there is a law showing that the level of skepticism rises in direct proportion to the magnitude of the claim.  I remember when cold fusion was announced and an eminent physicist saying to me that he thought it was about as probable as hammering a nail into a chunk of oak using a slab of warm butter.  Naysayers about Homo floresiensis arose at once, arguing that really the specimens are human beings with various physical and mental ailments making their brains small and (presumably) by our standards stupid (microcephalic).

Such criticism can be very irritating but overall it is healthy. If you make a bold claim, you had better be ready to back it up. Falk and the others set to work to justify their conclusions. In her case, she assembled a collection of skulls from people known to be suffering from the problems that the critics assigned to the hobbit, and then she could do a comparative analysis. She felt vindicated.  Microcephalic skulls show common patterns and the skulls of Homo floresiensis do not show these patterns. Healthy skulls show common patterns and the skulls of Homo floresiensis do show these patterns.

Over the years more evidence has come in supporting the distinctive and genuine nature of the hobbit.  For instance, the bones of the wrist are more like those of great apes and australopithecines than of modern humans. There are still doubters but the consensus is swinging (perhaps has already swung) in favor of the belief that the hobbit is something really new. Now of course we want more specimens, perhaps showing more of the evolution, and the hunt is on as I write.

Indeed, in the last couple of days, it has been announced (in the science magazine Nature) that it is possible that the hobbit was on Flores at least a million years ago. Researchers have found stone tools, similar in important respects to the tools found with the hobbit, and they have been able to date these new finds as being much, much older than anyone suspected. (They were able to do this because the tools were covered with volcanic ash that lent itself to ready dating.) No new specimens have been found along with these tools, but the search continues.

What does it all mean? In one sense, not a lot. In another sense, a great deal. Nothing on Flores upsets Darwinian evolutionary biology. The hobbit is small, and perhaps less than its ancestors, but that is quite to be expected on islands. In such conditions you often get extremes of growth both ways. Think for instance of the giant birds on New Zealand before humans arrived a thousand years ago. Animals can grow big because they don’t have competitors and are filling a niche (on New Zealand there were no tigers or lions, stopping the birds from becoming top predators) and they can grow small, especially if food supplies are scarce. On Flores there were pigmy elephants and giant rats, not to mention the Komodo dragon (a monster lizard).

My sense, although I stand open to correction here, is that the hobbit is not quite as exciting as Lucy, Australopithecus afarensis, discovered by Don Johanson and associates some 40 years ago. She was a mind blower because she had a small brain and yet walked upright. She answered the old question of which came first, bipedalism or major intelligence — it was the former. Although we have much yet to learn about it, the hobbit fits into the picture.

Having said this, however, the hobbit is truly very exciting. Indeed I would say that it was the scientific discovery of the decade. There were humanlike creatures on this earth at the same time as us. Now the quest must be on to find out whether they could talk — Are there brain or other indications of this ability? — and overall how intelligent they were and whether they exhibited signs of sophisticated sociability and so forth. It seems pretty obvious that they were not as bright as we are, but you have got to be very careful about simple identifications of brain size with IQ. The Neanderthals had bigger brains than we have and I challenge any modern university prof — with the obvious exception of Larry Summers, sometime president of Harvard — to say that the female students in class are thicker than the male students. Indeed, these days we are lucky to get male students at all.

What does Homo floresiensis mean outside the realm of straight science? If you believe in Adam and Eve, then I guess it is all a bit uncomfortable. But then if you believe in Adam and Eve, the fossil record has been a bit uncomfortable since 1891 when the Dutch doctor Eugene Dubois discovered Java Man (Homo erectus). What I do think it does is hammer home a message that was a constant theme in the writings of the late Stephen Jay Gould. There is no inevitable progress in evolution.  Because we are humans and because we are still around — if we weren’t, we wouldn’t be asking the questions — we tend to think that the whole of evolution is a long trek up to Homo sapiens. We are the apotheosis of the process. If you are English, as I was born, then you know that not only is there progress in general, but there is progress in particular to the inhabitants of a small island off the coast of France.

But this just isn’t true. We may be here but we are here by chance. As Gould used to say, punning on the comet that
hit the earth 65 million years ago wiping out the dinos and making possible the rise of the mammals, we owe our existence quite literally to our lucky stars. The hobbit underlines this theme. It is probably extinct now, but apparently for a million years or more it survived and reproduced quite happily on Flores. If our branch of the family had been wiped out by disease or something, it would have been — perhaps still would be — the representative of our lineage. Unless, like the Intelligent Design Theorists, you think that God intervenes directly in the process, the end of evolution (to date) could have been just over three feet tall with a brain smaller than a chimp.  Perhaps things would have been better, because in that case I doubt we would have had the horrors of the last century. No Mozart and Dickens, true. No Auschwitz and bomb, also true.

The hobbit shows that evolution is opportunistic. I am very glad that we humans appeared. I am doubly glad because, as far as Darwinian evolution is concerned, we might all have been running around the island of Flores killing pigmy elephants with our stone tools.