The Indonesian island of Flores lies north of Australia between Timor and Java. Even though it seems to be near Southeast Asia, it lies on the other side of the Wallace Line which separates the zoogeographical regions of Asia and Australia. The line represents the natural biological border which, because of the strong ocean currents, most animals simply cannot cross, and was first described by Alfred Russel Wallace who independently came upon the idea of evolution by natural selection at about the same time as Darwin. Because of the geographical separation, the evolutionary developments of species from both sides of the Wallace Line were different, so animal species which were once the same gradually started to differentiate.
The discovery of a small-skulled dwarf
Before the aforementioned Stone Age tools were discovered, it was believed that people had only crossed this natural border and arrived to Flores several tens of thousands years ago which is much later than the age of the stone tools found by archeologists on this Indonesian island implies. The Australian professor of archeology Michael Morwood who had the chance to examine the stone tools, quickly decided that the find deserved to be studied more thoroughly. He and his colleagues estimated that the Liang Bua cave (“cold cave” in the local language) on Flores was the place where it might be possible to find remains of prehistoric men. They began with the excavations of the cave which proved to be technically very demanding. That was because they had to dig another cave, more than fifteen meters deep, in order to reach the layers of sediments which were several tens of thousands years old.
After they had been digging for two years, carefully sifting and searching through everything they had brought to the surface, they finally got their share of luck. They found a tiny arm bone which, at first, they could not even identify. During the following year of digging they only found another tooth which could be human. In 2003, when they started to run out of funds for further excavation, they finally stumbled upon a well preserved human skeleton. Because the skull was very small, they were first convinced that it had belonged to a little girl, but they soon noticed that it also contained a wisdom tooth which little children do not yet have. As it turned out, they were not dealing with a child, but with a humanlike dwarf creature of the female sex, around 30 years old, that had an extremely small head. According to the bones found this midget was no more than a meter high.
Because of the small skull and other features that they were able to discern from the shape of the bones, the finding was classified as a new, until then still unknown biological species named Homo floresiensis, and the skeleton of the discovered dwarf dubbed LB1. On the same site they later found the remains of twelve other skeletons, all belonging to this extinct species of prehistoric dwarf men. Because of the popularity of the Lord of the Rings film trilogy at the time, the media simply named this supposedly new species of prehistoric men hobbits.
In the same layers, the remains of Stone Age tools, charcoal and elephant bones were also found which meant that these so-called hobbits had used fire and hunted elephants, so the find became even more unusual. The discovered remains of skeletons bore witness to the fact that hobbits had even smaller brains than today’s chimpanzees. Their brain volume amounted to a mere third of the average brain volume of humans today, but at the same time these hobbits were supposedly capable of using fire and crafting tools.
But the surprises kept on coming. By dating the layer of sediments in which the bones were discovered, archeologists found out that the sediments were no older than 30,000 years. After applying an even more precise method of measurement, which makes use of the ratio of carbon isotopes in the bones, they concluded that the discovered hobbit bones had to be between 13,000 and 94,000 years old. This meant that these dwarves had for a time lived during the same period as the modern man.
Extraordinarily developed humans or hobbits?
The story about the discovery took another twist when, in December 2004, the hobbit bones were temporarily passed into the hands of the 79-year-old expert on Indonesian paleontology, professor Teuku Jacob. After several months of research, he came to the conclusion that this find was not a new species of the genus Homo, but a degenerated dwarf form of a completely ordinary modern man who had a genetic defect which had prevented his skull to grow to a size, normal for healthy people. Regrettably, during his research, professor Jacob took the bones from where they were kept safe by the team that had made the discovery to his own laboratory. Allegedly he did not possess the appropriate permits to do so, but the worst of all was that in the end of February 2005 the bones he returned were slightly damaged and two of them were even missing. Of course, Jacob denied all allegations accusing him of unprofessional handling of an important discovery and claimed that the bones were already damaged when they were entrusted to him for examination. According to him, he handled the remains of the so-called hobbits with the same expertise as any other scientist who had ever dealt with such an important find.
The Indonesian professor’s hypothesis that this was not the case of a new species of the Homo genus, but a degenerated variety of members of our own Homo sapiens species has been reiterated by several Western experts. So far, however, it seems that most arguments remain on the side of those leaning towards the existence of the new Homo floresiensis species. Exact analyses of the preserved hobbit skull enabled them to create a computer generated model of the dwarf brain structure and reveal that it showed no such characteristics as are typical in people today who had developed a similarly small skull as a result of a genetic defect. Although the hobbit brain was even slightly smaller than that of a today’s chimpanzee, it had a significantly different structure. A look into the structure of the skull enabled scientists to find out that, in comparison to chimpanzees, the parts of the brain responsible for higher cognitive activities were much more developed in hobbits.
Other discoveries have been made, of which a number of examples exist, that stand against the theory of hobbits as a pathological form of ordinary humans. Of course, it is difficult to rely on a single 18,000-year-old skull to provide evidence from which the characteristics of an entire population could be determined, because the being in question could have had an illness as a result of which its bones could not be considered as typical of the entire species. Fortunately, a number of teeth and parts of jaws have been found, so the doubts of the skeptics can now be dismissed. It would be difficult to explain, for example, how the jaws of two hobbits that lived several thousands of years apart just happened to have the same pathological deformation.
Similarly, some hand bones characteristic of humans are much different in shape than in apes and older forms of human ancestors. Humans have a very well developed ability to grip things with the thumb and the index finger which comes in very handy in all kinds of different activities, while, on the other hand, this bone structure is not as helpful when it comes to hanging from tree branches or crush nuts. It is interesting that the structure of these essential hand bones in hobbits is much more similar to the structure common in apes than to that of humans. This serves as further evidence that hobbits were most likely not a degenerated form of modern humans, but a species of their own.
The final confirmation of the discovery of a new species and not merely deformed humans could only be made possible with an analysis of mitochondrial DNA. However, archeologists have so far been unable to isolate the excavated hobbit bones. They hope to succeed in doing so with the help of a tooth that has been carefully stored ever since it was discovered, so that the remains of the biological material would not get contaminated. If the isolation of the DNA succeeds, we will definitely hear more about it.
The branch that grew away
The discovery of the unusual skeletons on the Indonesian island of Flores reminds us once more that evolution is by no means a strictly linear process which runs straight from the simpler to the more complex forms of life. This conception of evolution as a vehicle of development is false. Biologists like to tell us that the easiest way to imagine evolutionary development is by drawing an analogy with a tree and its branches. Just as a tree grows into different branches which grow side by side, biological species coming from a common ancestor evolve into different, new species.
In the case of the hobbits from the isle of Flores it is most likely a matter of a biological species which already separated from the evolutionary branch from which modern humans have evolved around two million years ago, but succeeded to survive almost until the time when humans started to build their first cities. Before the discoveries on the island of Flores were made, Neanderthals were believed to be the last species of the Homo genus to have shared the living space with the modern man before they became extinct 24,000 years ago. If the age estimates are correct, Indonesian hobbits did not die out until 12,000 years ago which is even later than Neanderthals did. Even though experts claim that the chances of that are almost non existent, many are excited by the thought that even today, in some remote little island, there could live a group of little people with tiny heads that could build a fire, but still would not be human.
Posts
0 comments:
Post a Comment