A long-lost cousin

A team of anthropologists find in a remote Indonesian island the remains of what they say was a member of a distinct human species that coexisted with Homo sapiens.

IN 1831, when only 20, Charles Darwin left England on the HMS Beagle for the Galapagos. This archipelago of volcanic islands in the Pacific Ocean off Ecuador provided him the inspiration and much of the data for his 30 years of study. The work resulted in his theory of evolution, one of the most revolutionary ideas that science has ever known. Since then, isolated islands have been considered the Petri dishes of evolution because of the opportunities they provide for the study of the development of organisms in varying environments.

Anthropology received another major shot in the arm in October 2004 when an article published in the British science journal Nature stated that the remains of a hominid, of a previously unknown species of miniature human, were found in Flores, a remote Indonesian island east of Bali. Called Homo floresiensis, or in layman's language the Flores man, it was claimed to be the first new species discovered after the Neanderthal man was unearthed in Europe some 200 years ago. The team of Australian and Indonesian archaeologists who found it said that it was the smallest of the 10 known species of the genus Homo, the hominid that emerged about two and a half million years ago from Africa. Nicknamed `hobbits' by the team, these hominids seemed quite as exciting as those that populated the Middle Earth in J.R.R. Tolkien's Lord of the Rings.

The term `hominid' refers to the members of the biological human family, Hominidae, which family includes all living humans and all human ancestors. Hominids form a super-family distinct from the old-world apes and monkeys, our nearest living biological kin. Hence modern apes are not our ancestors but more appropriately our siblings. The common primate ancestor of humans and living old-world apes went extinct several million years ago.

Hominids are remarkable for the sheer diversity of their fossil record. There is no other mammal found over such a geographic and ecological range, or one that has evolved so many forms of behaviour within just a few million years. As their genetic variability increased, it added to the uncertainties in geological dating and fossil reconstruction.

Apparently, our evolution was helped along by the human tendency, seen even today, to migrate. Apart from the fact that early humans were a restless bunch, they were also evolving at an alarming speed, increasing the number of the regional variants of hominids. Combined with geographic isolation in some cases we see the distinct evolution of different hominid groups. Hominid fossils are therefore considered critical in the study of evolution. Complete skeletal finds are rare. Teeth and lower jaws are the most common.

Skulls are considered the best evidence to help understand the process of evolution. But they are almost never found intact and generally have to be reconstructed from fossil fragments. Endocasts of the inside of the skull offer evidence about the shape and size of the brain. This anatomy is used to infer the cognitive capacities of different species. Any tools recovered alongside the fossils buttress the conclusions drawn from the hominid fragments.

In the trove of fragmented bones retrieved in Flores, the most complete skeleton unearthed is said to be that of an adult female three feet (almost one metre) tall, dated as only 18,000 years old. She has been called Liang Bua 1, after the limestone cave in which she was found and which has been the site of archaeological digs for almost 40 years. The scientists have in all recovered about seven skeletons, with the oldest being 95,000 years old and the youngest a mere 12,000 years. The most striking feature of the discovery was how recently the creatures coexisted with our own ancestors, Homo sapiens, said Professor Dan Bradley, a genetic anthropologist in Trinity College, Dublin. "The real thing is their age," he says. "They lived only 12,000 years ago at a time when our ancestors were starting to herd goats and live like we do today. Twelve thousand years is the blink of an eye in the history of a species. This means we just missed out on having surviving cousins on the planet. They almost made it to the present day."

Our diminutive relations then must have overlapped with our kind of people for at least 25,000 years. This implies that Homo floresiensis survived for thousands of years, almost until the advent of recorded history, before becoming extinct. Thus they most certainly must have been alive when modern Homo sapiens arrived in the region. Perhaps they even went hunting in the same woods at the same time as the ancestors of today's islanders.

According to the people of Flores, these little hairy people or the Ebu Gogo were alive when the Dutch trading ships sailed to those parts some 300 years ago, and even survived until as recently as a hundred years ago. The islanders did not mistreat the so-called hobbits, although they certainly did notice them. They talk of small creatures that were about three feet tall and weighed as much as a three-year old. They also have legends about these shy creatures that murmured to each other or repeated, parrot-like, what they heard.

According to co-discoverer Professor Peter Brown, there have always been legends about small people. The Irish had their leprechauns, the Germans had their elves, and the Australians speak of their Yowies. The little Ebu Gogo obviously represent the folk memory of Flores kept alive by oral history.

JUST a little over three feet tall, Liang Bua 1 had long arms and a small skull. Her long arm, which is an interesting characteristic, could indicate that Homo floresiensis were adept at climbing trees. Perhaps she kept her young on trees to keep them safe from predators.

When it was first discovered, the partial skeleton gave the impression that it belonged to a child. But further investigations revealed wear on the teeth and growth lines on the skull, confirming that it was that of an adult. The leg bone indicated that it walked upright, and the pelvis that it belonged to a female.

The conjecture was that this species might have evolved its small size in response to the scarcity of resources on the island. It is said that when creatures get marooned on islands they could evolve along unpredictable lines - they could grow big or become small.

The small size of Liang Bua and the almost absolute isolation of Flores, scientists say, would substantiate invoking the island rule. On the other hand, modern African pygmies are small because of reduced levels of certain growth factors. The same reasons may not be applicable to Homo floresiensis.

"Insular dwarfing" is an acknowledged evolutionary process, which results in either very small or very large organisms as a result of isolation within an island population, according to the authors of the new report. In environments that are segregated for long periods, non-predatory creatures adapt to food scarcity by becoming smaller, particularly where bigness is not required because there are no large predators around. At the same time, smaller predatory creatures get bigger since they face no competition from larger creatures.

They thus explain how early populations of Homo erectus who reached Flores became downsized after thousands of years. Something similar happened to their main prey, the elephants, known as stegodons, which miniaturised to buffalo size, whereas the lizards grew long and came to be known as the komodo dragons.

Since the remains are relatively recent and not entirely fossilised, scientists are even hopeful that they may yield some deoxyribonucleic acid (DNA). The genetic information could yield an entirely new perspective of origin of humankind.

This dwarf human shatters the venerated scientific belief that Homo sapiens began some 160,000 years ago to replace methodically all other humans that walked upright and have possessed the earth to their complete exclusion for tens of thousands of years.

Homo floresiensis is seen to have features that appear to have been borrowed from the extinct primitive man. Yet he crossed the archaeological timelines associated both with Homo erectus and Homo sapiens. This indicates that dramatic changes in DNA and the creation of a new species happened not millions of years ago but rather recently in terms of evolutionary time.

It also suggests a lengthy coexistence of two different species of man, until a massive volcano caused the extinction of Homo floresiensis. Scientists have not so far been able to clarify how these different species coexisted in adjacent and overlapping regions or interacted with each other. Liang Bua will certainly make this puzzle a little more complex.

None of these possibilities are consistent with traditional evolutionary theory. Africa, thus far acknowledged as the cradle of humanity, may not hold all the original secrets of the human race.

WITH the youngest skeleton from the limestone caves dated at a mere 12,000 years old, conjectures abound as to how these people reached the remote island. Some say that the first group, probably of a form of Homo erectus, could have reached the island perhaps a million years ago by cobbling together some kind of a raft or by walking across a low land-bridge that might have existed then.

Our long-lost cousin Liang Bua 1 could well be the desktop beauty for scientists across continents. Her surfacing has definitely put Flores on the map. A large number of tourists are wending their way to her abode in the giant limestone caves situated beyond the volcanic shores of Komodos. Some tourists hope to stumble upon one of these creatures in the dense vegetation of Flores. Many islanders were willing to act as guides to tourists in search of the little creatures.

According to team leader Professor Michael Morwood of the University of New England in Australia, who worked at the Indonesian site, "it means two different types of species existed at the same time".

"This finding really does rewrite our knowledge of human evolution," said Chris Stringer, who researches on human origins at the Natural History Museum in London. Even if one distinct species of humans is found to have lived alongside modern man, it reinforces the fact of recent human diversity and could fundamentally change our view of ourselves.

Fossil finds do become the subject of great media attention, and the Liang Bua remains did get more than their fair share of it. As was to be expected, the next phase, of refutation by other experts, began soon enough.

A leading Indonesian scientist, Professor Teuku Jacob, Chief Palaeontologist at the Gadjah Mada University in Indonesia, challenged the theory that the fossilised bones of Flores were at all from a previously unknown human species. He argued that the cave's remains merely belonged to a subspecies of Homo sapiens, a kind of human dwarfs, and that their small brain volumes was a sign of mental abnormality rather than evidence of a separate species. He maintained that the small skull of Liang Bua 1 was related to a mental defect, microcephaly, which shrank human brains to the size of a chimpanzee's. He argued that many people on Flores suffered from this out-of-the-ordinary pathology and that the much-publicised remains related to a local pygmy population.

With several other prominent researchers from Australia, Turkey and the United States also supporting this view, The Times felt compelled to say: "A find heralded as the greatest discovery in anthropology for a century has degenerated into one of its greatest rows."

However, other scientists assert that the article in Nature was rigorously refereed and reviewed by top palaeontologists and they would not have been taken in by spurious claims. They also say that Jacob should have conveyed his dissenting opinion through another academic article rather than drag the disagreement into the public arena. Paleo-anthropologists, they claim, could have done without this kind of disservice.

In this season of discord, creationists also keyed in their strong religious argument that the failure to reach a definite conclusion about the lady of Liang Bua showed that the theory of evolution, with its mechanisms of mutation and natural selection, could never hope to explain sufficiently the complexity of life, and that everything had emerged as the result of a higher will and purpose.

The latest news in this evolution is another article published in the magazine Science in March, which supports the idea that the hobbit represents a new dwarf species and that the microcephaly theory can be totally rejected from a study of its braincase.

This first major study conducted since the discovery was announced, was based on a 3D digital endocast, which showed that the brain of Homo floresiensis was advanced, apart from being unique in its design. Their constructed brain showed similarities to those of both Homo erectus and the modern human. As compared to the average human brain of 1,400 cubic centimetres, its brain size was about 417 cc, or the size of a chimpanzee's, but very different in shape. Its shape was not that of a microcephalic, and the brain-to-body size ratio disproved the theory that Liang Bua 1 was a pigmy.

Professor Dean Falk, co-author and anthropologist at the Florida State University in the U.S., says that these hobbits were either descendants of Homo erectus who had shrunk during their evolution, or they descended from some other small-bodied ancestors. She says the skull has features that harken towards modern humans, such as the frontal lobe and the temporal lobes at the sides and the back of the brain. The frontal lobe, the area responsible for intelligent thinking, as well as a depression at the back of the brain, suggest advanced development.

Another scientist cites this development as the reason for the three-foot hobbit being able to make sophisticated stone tools, hunt elephants and cross oceans.

A myth that the Indonesian fossil may now have broken is that you need a particular brain size for intelligent activity. It only depends on how many features you can pack in a tiny brain space. With a brain no larger than that of a chimpanzee, these little people did make miniature tools. And they perhaps also did some cooking, if the charred remains of a small animal found in their cave are anything to go by.

Professor Dean Falk's affirmation that Liang Bua 1 is a new species would lend credence to the theory that these miniature people are indeed distinct.

But not all scientists are swayed by the new study. Perhaps the key to this clash of opinions may lie in a detailed DNA analysis of the hominid's remains. In the meantime, the skull was also said to have been temporarily moved by Professor Teuku Jacob to his own laboratory in Jakarta, thus disrupting a further study of the find. Others allege that some of the remains were also partially destroyed during this transportation.

The Liang Bua lady, whose skull has aroused such fancy among scientists, does connect with humankind in some fashion, no matter who she finally turns out to be.