When a new species of humanity was found on the Indonesian island of Flores, it was thought to probably be a descendent of Homo Erectus that had experienced island dwarfism. New evidence, however, links Homo floresiensis, widely known as hobbits, to Homo habilis, a much more primitive member of the human family. While this resolves some mysteries, it makes the question of how the hobbits reached Flores even more puzzling. The ancestors of the real hobbits went on a journey far longer, and possibly more intimidating, than from The Shire to Mordor.
Attempts to place the hobbits on the family tree, aside from those by researchers convinced they were Homo Sapiens with a genetic disease, have usually focused on finding the best match for the skull and lower jaw. Although these are arguably the most distinctive features, such studies are necessarily incomplete, so Professor Colin Groves and Dr Debbi Argue of the Australian National University went much broader, using 133 data points across the body. By comparing the size and shape of these parts of the anatomy, the authors revealed a far closer resemblance to Homo habilis than Homo erectus.
“We looked at whether Homo floresiensis could be descended from Homo erectus,” Argue said in a statement. “We found that if you try and link them on the family tree, you get a very unsupported result. All the tests say it doesn’t fit – it’s just not a viable theory.”
Argue and Groves published their findings in the Journal of Human Evolution.
“The analyses show that on the family tree, Homo floresiensis was likely a sister species of Homo habilis. It means these two shared a common ancestor,” Argue added. “It’s possible that Homo floresiensis evolved in Africa and migrated, or the common ancestor moved from Africa then evolved into Homo floresiensis somewhere.”
Groves told IFLScience that an alternative theory – the hobbits were in fact not members of the human genus at all, but related to the even earlier ancestor Australopithecus – could not be ruled out. “They'd probably got beyond the Australopithocene stage, but really they are at the same sort of primitive level,” Groves said.
Groves added that while initial interpretations of the tools found with the hobbits' bones were that they were much more advanced than those of Homo habilis, on closer examination they appear to have been at a similar technological level.
The relationship to species that died out more than a million years before the hobbits explains some of their physical features, but makes the question of how they got to Flores even more puzzling. No evidence of Homo habilis, let alone Australopithecus, has been found outside Africa.
Groves told IFLScience: “An animal spreads its range as suitable habitat extends. So at some time during the early Pleistocene, the habitat in which early Homo evolved must have spread through the Middle East and Asia.”
The failure to find evidence of hobbit relatives elsewhere at least partly reflects a shortage of fossils of the right age from most of southern and south-east Asia. “There are some deposits in the foothills of the Himalayas, including apes,” Groves said. These don't contain early humans, suggesting they may not have ventured so far north. Instead, migrations are presumed to have hugged the coast through Arabia and India, areas where we lack a record of any bones from the appropriate period. Eventually, Groves hopes, “something will turn up” to indicate places the hobbits' forerunners visited in their long journey.
Flores is east of the Wallace Line, meaning it has not been linked to Asia for millions of years. It is unclear whether the hobbits' ancestors floated across on logs, as some animals did, or were able to build boats capable of crossing narrow ocean straits.
Homo erectus was the great traveler of the human family before Homo sapiens came along. Their remains are scattered widely across Asia, including on Java, not too far from Flores, and they survived until 143,000 years ago, overlapping with the hobbit-like remains dating from 700,000 years ago at Mata Menge, central Flores. However, it was always puzzling to anthropologists why a species descended from Homo erectus would have features that more closely resembled earlier ancestors.