New bones attributed to Homo floresiensis — aka the "Hobbit human" — along with other recent findings, are helping to reveal what members of this species looked like, how they behaved and their origins.
The latest findings, described in a Journal of Human Evolution paper, are wrist bones unearthed on the Indonesian island of Flores. Since they are nearly identical to other such bones for the Hobbit found at the site, they refute claims that H. floresiensis never existed.
"The tiny people from Flores were not simply diseased modern humans," Caley Orr, lead author of the paper, told Discovery News.
"The new species of human stood approximately 3' 6" tall, giving it its nickname 'The Hobbit,'" continued Orr, who is an assistant professor in the Department of Anatomy at Midwestern University.
He said that they were "similar to modern humans in many respects." For example, he explained that they walked on two legs, had small canine teeth, and lived what appears to have been an iconic "cave man'" lifestyle.
"Stone tools and evidence of fire use were found in the cave, along with the remains of butchered animals, such as Stegodon (an extinct elephant relative), indicating that meat was a part of diet," Orr said.
He and his colleagues, however, also point out the differences between the Hobbit individuals and modern humans.
The Hobbits had arms that were longer than their legs, giving them a slightly more ape-like structure. Their skulls had no bony chins, so their faces had more of an oval shape. Their forehead was sloping. The inferred brain size was tiny, putting them in the IQ range of chimpanzees.
"Remarkably, the feet were also long relative to the legs, as fantasy fans might expect of a Hobbit," he added.
The Hobbit's wrist looked like that of early human relatives, such as Australopithecus, but the key ancestral candidate now is Homo erectus, "Upright Man."
It is possible that a population of H. erectus became stranded on the Indonesian island and dwarfed there over time. Orr said that "sometimes happens to larger animals that adapt to small island environments."
A problem, however, is that H. erectus is somewhat more modern looking than the Hobbit, so researchers are still seeking more clues.
Another question concerns whether or not the Hobbits ever mated with modern humans. There is evidence that happened to Neanderthals, which have left traces of their genome in modern human DNA. So far, however, conditions have not been right to extract DNA from H. floresiensis bones.
Nonetheless, the Hobbit — which went extinct relatively recently during the Pleistocene — is now better known due to the new discoveries.
"These fossils provide further, clear evidence that H. floresiensis is in no way a pathological modern human, or that its primitive morphology is related simply to its small body size," said Tracy Kivell, a paleoanthropologist from the Max Planck Institute for Evolutionary Anthropology. "Instead, it is clearly its own, unique and very intriguing species."
Kivell added, "What is particularly interesting is that H. floresiensis is associated with such a long, well-documented history of stone tools. (Its primitive hand and wrist were) still apparently capable of making and using stone tools, suggesting that H. floresiensis solved the morphological and manipulative demands of tool-making and tool-use in a different way than Neanderthals and ourselves."
Orr and his team continue to study the Hobbit humans, with at least one other paper about the interesting species in the works.