OLL LEWIS: There and Back Again

The British members of the team return to the UK on Sunday, and we are agog to find out more about what they have done. In the meantime here's Oll....

In 2003 a team of archaeologists from Australia and Indonesia made what is the most ground-breaking discovery in human evolutionary history in the lifetimes of most people alive today. On the island of Flores to the southeast of Sumatra and Borneo, when looking for evidence to support timings of human migrations in our evolutionary history, they investigated Liang Bua cave in the hope of finding evidence of ancient human habitation. What they found surpassed their wildest expectations when they happened upon stone tools, evidence of animal butchery and hunting, evidence of use of fire and an almost complete small skeleton on the floor of the cave along with more bones, from other individuals, that looked like they may be human.

The bones were not human, however; rather than Homo sapiens they had discovered the bones of a previously unknown hominid species, which became known as Homo floresiensis or more colloquially, ‘hobbits.’ The bones of their first near-complete specimen (LB1) were very fragile and moist all the way through, and the archaeologists compared their constituency with that of wet blotting paper. It was clear that without drying out they would be too fragile to properly examine, so they did this before digging them up. It was on inspection that they noticed just how unusual the bones were. At first glance the archaeologists might have assumed from the small size of the cranium and skeleton of LB1, which would have been about 1.06 metres (3ft6ins) in height, that they were looking at the body of a child, but the bones were all fully formed, indicating that LB1 was an adult. LB1 is now thought to be the skeleton of a 30-year-old female. Another, less complete, specimen from the cave (LB8) had its height estimated based on the size of its tibia and is thought to have stood at 1.09 metres (3ft7ins). These heights are significantly shorter than the average heights of any extant adult race or tribe of H. sapiens, the smallest of which, the Twa, Semang and Andamanese peoples all have an average height of 1.37 metres (4ft6ins) for adult females.

Another identifying factor of H. floresiensis was the cranial capacity: only 380 cubic centimetres, which is comparable to that of a chimpanzee, about half the capacity of Homo erectus and a quarter of the size of H. sapiens. H. floresiensis was - according to associated finds in the cave such as stone tools, evidence of fire and the butchered remains of stegodon - certainly quite intelligent despite its small brain, this is borne out by the comparably large overall proportion of the brain that seems to be given over to Brodmann area 10 in H. floresiensis, which is as big as that of H. sapiens despite the small size of the rest of the brain. The functions of Brodmann area 10 is little understood but it is thought that it may be involved in multitasking and cognitive branching.

Other morphological differences between H. floresiensis and other hominids include their relatively large feet in relation to body size (which would also result in larger hands), apparent lack of chin, less twisting of limb bones and a shorter big toe in relation to the other toe bones.

What makes H. floresiensis so remarkable, though, is its survival as a species so near to the present day. The species is only thought to have become extinct following the eruption of a nearby volcano some 12,000 years ago, which is about 12,000 years after the approximate time Homo neanderthalensis became extinct. The final extinction of H. floresiensis may have occurred in much more modern times if the folklore of Nage people, Flores’s modern indigenous people, is to be believed.

The Nage people’s folktales speak of a race of short hairy men they call the Ebu Gogo. The Nage people claim to have wiped out the Ebu Gogo in the 18th century, apart from one pair who fled into the forest, by burning them alive in their cave. The Nage people claim to have done this in retaliation for regular theft of food and kidnapping of their children by the Ebu Gogo. If it was the case that the Ebu Gogo were a remnant population of H. floresiensis, which is by no means certain even if the Ebu Gogo did exist, then it could go down in history as the most tragic extinction perpetrated by human hands in history: to lose the only other known extant species of our genus to a natural disaster 12,000 years ago is one thing, but to loose it only 200 years ago in an act of genocide because it was stealing berries is another thing entirely.