Focus: Human Evolution
On one island visited by Sinbad during his travels, he found a giant bird with the wingspan of a whale, while Odysseus, according to Homer, discovered an island race of one-eyed giants who ate humans.
Great stories, but tame stuff compared with reality. On the island of Flores in the Malay Archipelago, scientists have found remains of a race of three-foot high humans who hunted pony-sized elephants and rats as big as dogs and who battled dragons with saliva laced with deadly bacteria. When it comes to the fantastic, you can never beat science.
Certainly, the furore that surrounded last week's reports that fossil-hunters have discovered the bones of a new human species, Homo floresiensis , is scarcely surprising. This little hominid lived a mere 18,000 years ago, it transpires (and so must have shared Flores with Homo sapiens for millennia), made some nifty stone tools and butchered mini-elephants (called stegadons) with alacrity. As Cambridge anthropologist Robert Foley says: 'Discoveries don't get better than this.'
Now the hunt is on for living relatives of Flores's little folk (local legends speak of a tiny race of jungle dwellers called the Ebu Gogo), not just on the island but around the rest of the Malay Archipelago, a string of mysterious tropical islands - home to orang-utans, giant turtles and rare birds and bats - that spread like jewels between Asia and Australia. Strange little people hiding in this exotic jungle: Rider Haggard could not have done better.
But the sensational nature of the discovery - by a team led by Professor Peter Brown, of New England University, New South Wales - goes far beyond biological curiosity. The fragments of bone and stone tool he has dug from a cave hidden in western Flores raise issues that could transform our ideas of what it means to be a human being. How did these people (dubbed hobbits by the world's press, to the fury of Brown, who now hangs up his phone at the mention of the h-word) reach Flores, which has been an island for millions of years? Why did their stature diminish? And how did the Flores folk flourish and make sophisticated tools after their brains had shrunk in response to evolutionary pressures?
Consider Homo floresiensis 's arrival on Flores. More than a million years ago, the first members of our lineage, Homo erectus - a race of tall, thin ape-men - emerged from their African homeland and colonised Asia. And there they stopped at the edge of the Indian ocean. Or at least that's what scientists thought, for no report of erectus having travelled over water has ever been substantiated - until now. According to Brown, stone tools found on Flores shows it has been occupied for hundreds of thousands of years.
'It is possible erectus people sailed in crude boats, though Homo sapiens are the only known member of our species to have built boats or rafts,' says Professor Chris Stringer of the Natural History Museum in London. 'Certainly, nothing would surprise me after this discovery. But they could also have been carried on floating mats of vegetation. This region has dozens of volcanoes and is battered by earthquakes and tidal waves. These could have swept these people out to sea on these mats. It may sound unlikely but it only had to happen once and they had a million years to play with.'
Then, trapped in their new home, erectus began to shrink. 'Island dwarfing is well-known,' says Professor Adrian Lister of University College London. 'With limited resources and lack of predators on islands, large mammals get smaller and little ones get bigger over succeeding generations. They tend to gravitate to the dimensions of a large rabbit, the most energy efficient size for a mammal.'
Hence the tiny dimensions of Homo floresiensis and those pygmy, elephant-like stegadons - though, again, current explanations are only partially effective. These animals shrank, but not the komodo dragon, a species of giant lizard unique to this area. It may have remained huge because it could hunt pygmy elephants, and, possibly, Flores folk, scientists suggest.
Certainly, the komodo can easily kill adult humans. And its saliva is riddled with pathogenic bacteria ('poisonous halitosis', as the writer David Quammen describes it).
So how then did these little folk survive in what Stringer describes as 'this weird world'? Where could they hide? Most legends speak of Ebu Gogo as cave dwellers, and Brown's discovery was made inside the great cavern of Liang Bua, in the west side of Flores. Again, Stringer is not so sure, noting that Homo floresiensis arm bones are exceptionally long, a feature shared with apes and which suggests an arboreal lifestyle. 'I think it is more likely they may have hidden in trees, especially when with young ones,' Stringer says.
And then there is the issue of floresiensis's brain size. 'Even by the standards of early apemen, their cranial capacities appear to be very small, little more than a chimpanzee's,' says Oxford University's Alan Cooper. 'How they retained the capacity to make even crude stone tools is a major headache.' In short, being brainy isn't the only evolutionary option open to human beings, it transpires. As Dr Charles Lockwood of University College London puts it: 'This discovery is a wonderful demonstration of the fact that there are many different ways to be human.'
Indeed, only a few dozen millennia in the past, we now know there were at least three different varieties of human being; Homo sapiens , Neanderthals and, as we have just discovered, Homo floresiensis . 'We have got to get rid of the idea that because there is only one species of human being today, this has always been true,' says Israeli palaeontologist Yoel Rak. 'For most of our evolution the opposite was probably true. Think of that scene in Star Wars - in the bar where you see all kinds of aliens playing and drinking and talking together. That image gives a better flavour of our evolutionary past.'
In fact, it may not just be our evolutionary past, but our present as well - for there are some researchers who believe the Flores folk survive in some hidden pockets of the island, a point made by Father John Prior, a Catholic missionary who has lived there since the 1970s. 'I've heard stories for decades about these so-called little people,' he told The Observer . 'Legends about dwarfs living in caves - not the forests - are found in the west of the island, where the skeletons were found in Liang Bua.'
Discovering a tribe of these people, though unlikely, would be a major boost for evolutionary science. However, it would most probably be a total disaster for Homo floresiensis . The eradication of the Tasmanian aborigine in the 19th century is a grim but fitting example. This suggests that a more appropriate cinematic illustration for our story should come, not from Star Wars , but from the closing scene of ET , when space-suited scientists try to capture and experiment on the little alien.
But the prospect of such encounters must remain low, and, of course, fiction has proved a very poor guide to scientific reality, as the story of the island of Flores has so starkly demonstrated.
Source: Guardian Newspapers
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