Sydney: Homo floresiensis, a species of tiny human discovered on the Indonesian island of Flores in 2003, most likely evolved from an ancestor in Africa and not from Homo erectus - an ancestor to modern humans - as has been widely believed, a study says.
The researchers believe that their findings, published in the Journal of Human Evolution, should help put to rest a hotly contested debate about the origin of Homo floresiensis.
"We can be 99 per cent sure it's not related to Homo erectus and nearly 100 per cent chance it isn't a malformed Homo sapiens," said Mike Lee of Australia's Flinders University and the South Australian Museum.
Homo floresiensis, dubbed "the hobbits" due to their small stature, were most likely a sister species of Homo habilis -- one of the earliest known species of human found in Africa 1.75 million years ago, the study said.
Data from the study concluded there was no evidence for the popular theory that Homo floresiensis evolved from the much larger Homo erectus, the only other early hominid known to have lived in the region with fossils discovered on the Indonesian mainland of Java.
"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," said study leader Debbie Argue of the Australian National University.
"It's possible that Homo floresiensis evolved in Africa and migrated, or the common ancestor moved from Africa then evolved into Homo floresiensis somewhere," Argue said.
Homo floresiensis is known to have lived on Flores until as recently as 54,000 years ago.
Where previous research had focused mostly on the skull and lower jaw, this study used 133 data points ranging across the skull, jaws, teeth, arms, legs and shoulders.
None of the data supported the theory that Homo floresiensis evolved from Homo erectus, Argue said.
"We looked at whether Homo floresiensis could be descended from Homo erectus," she said.
"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 said.
This was supported by the fact that in many features, such as the structure of the jaw, Homo floresiensis was more primitive than Homo erectus, she added.