What are the Hobbits Flores?

At age 29, she stood one metre tall and weighed 30 kilograms. Her feet were long with curved toes, her leg bones proportionately short, and her arms tended to bend out to the side rather than forwards. She had a tiny, ape-sized brain but used tools, hunted and cooked meat. Around a million years ago, by fluke or miracle, her ancestors reached the isolated island we know today as Flores, Indonesia.

It was a hostile world crawling with venomous dragons, stegodons, giant storks and rats. Yet her people managed to hold on there until as recently as 18,000 years ago.

She was formally anointed Homo floresiensis, catalogued as LB1, and playfully nicknamed “Hobbit” due to her short stature and disproportionately large feet. But just who was she?

“Everybody wants to know who they were and where they came from,” says Florida State University paleo-anthropologist Dean Falk.

On the western end of Flores, in a cathedral-like limestone cave called Liang Bua, archaeologists began excavating for evidence of early man in the 1950s, but stopped when they reached a layer of 17,000-year-old pyroclastic ash. It was a sure sign of a cataclysmic event, possibly a volcanic eruption, that would have killed everything that couldn’t fly or swim away.

In 2003, a team led by University of Wollongong archaeologist Mike Morwood, resumed work at Liang Bua and, digging far below the pyroclastic layer, uncovered a more than 40 percent complete hominid skeleton suspended in damp clay. The bones were the consistency of saturated parchment and turned to mush with the slightest pressure. They were gingerly exhumed, carefully dried, CAT scanned and replicated.

In late 2004, Morwood and his colleagues announced in the prestigious journal Nature that LB1 (named after Liang Bua), while displaying a mosaic of primitive features that would align her more with Australopithecines, the earliest of the hominids, her face and teeth placed her firmly in the family of man, the genus Homo.

When LB1 was first introduced to the world, scientists assumed she was a member of the species Homo erectus, which emerged in Africa nearly two million years ago and eventually roamed as far as Southeast Asia. Sure, she was smaller than expected, but that was explained away as either a growth-stunting disease or insular dwarfing as Hobbits adapted to the conditions on Flores.

However, more detailed study of LB1’s anatomy is turning up traits that put her origins much earlier than that of Homo erectus. That a much more “primitive” member of the human family found its way out of Africa, and that an entirely separate species of human existed at the same time as more modern humans, are facts challenging accepted views of how man evolved. “Every now and then something will shake things up and you go, ‘Oops! Back to the drawing board.’ This may be one of those moments,” says Falk.

For instance, it was long believed that the species in the Homo genus, including Homo erectus and modernday Homo sapiens, evolved one after another in a relatively straight line. But the Hobbits are raising the possibility that the human tree is more complicated and messy – more like a bush sprouting in many directions.

“The case now is very clear there have been a number of different lineages out there, a lot of which go extinct,” says paleo-anthropologist William Harcourt-Smith of the American Museum of Natural History in New York City. “Which particular lineage eventually turns into something that turns into us is open to debate.”

Not everyone in the scientific community is ready to welcome Hobbits as a new member to the human family. Jeffrey H. Schwartz, a University of Pittsburgh professor of anthropology who has studied virtually every known hominid fossil, questions whether the pieces that constitute LB1 are really from the same hominid, the same species or even the same individual. “It just struck me that if these bits and pieces did go together as a hominid,” he says, “it was the most Rube Goldberg- ian hominid I’d come across,” referring to the American cartoonist who envisaged complicated machines that performed simple tasks.

Anatomist William Jungers of Stony Brook University in New York, a key member of the scientific team that introduced Hobbits to the world, has been fending off the challenges to their place in evolution. “If it was 2.5 million years old and found in East Africa,” he says, “people would have said, ‘Well, this is an interesting fossil in the Australopith to Homo transition.’ The fact that it’s 18,000 years ago in Southeast Asia is what has amazed and boggled minds.”

Closer examination of the Hobbits’ anatomy is turning up intriguing findings. Consider their brain size – it has long been thought that the brain has continuously increased in size as evolution progressed over the past two million years.

Dean Falk discovered that LB1 didn’t fit into this tidy picture. Taking the dimensions of the brain case, she created a virtual digital 3-D endocast of LB1’s brain, a high-tech process that models a brain right down to the gyri “bumps” and fulsi “grooves” in the grey matter.

Based on the brain-case volume of 417 cubic centimetres (compared to 1,300-1,600 cubic centimetres for modern humans), Falk says, “I thought the brain was going to look chimp-like.” Instead, she found the telltale signature of a much more advanced brain, one that could perform higher functions like planning ahead, imagining scenarios, “glueing together” information from all the senses. “It totally blew me away,” she recalls.

Ian Tattersall, a paleo-anthropologist at the American Museum of Natural History who has examined every known hominid fossil, is sceptical of what can be inferred from brain endocasts. “Paleo-neurologists can’t agree on what all the bumps and furrows on the outside of the brain – or even the brain size itself means,” he says.

Meanwhile, Sue Larson, Jungers’ colleague at Stony Brook, analysed LB1’s shoulder blade and reported that its characteristics were derived from a very early ancestor, “perhaps at the very origins of the genus Homo”. In other words, early versions of man could have been migrating out of Africa earlier than previously thought.

The long-accepted view, laid out by evolutionary biologist Ernst Mayr in the 1940s, was that Homo erectus was the first species to achieve the required level of cultural organisation or intellectual development to leave Africa. However, an examination of non-human species does not back this up. Consider apes: fossil records show that they moved out of Africa between 25 and 5 million years ago. “Somehow when you’re dealing with humans, the same biological roles that we’re comfortable with for animals don’t apply,” Larson says.

So let’s say that bands of Lucy-like pre-Hobbits did wander out of Africa, ranged across southern Asia and eventually came upon the Indonesian islands. At that time, when sea levels were much lower than they are today, they would have been able to walk between many of the islands. But even then Flores was isolated by deep water and strong currents. So how did they make the crossing?