Tuesday, August 22, 2006 Posted: 1412 GMT (2212 HKT)
The skull of Indonesia's hobbit-sized human, left, and one of a modern human.
Previous researchers concluded in 2004 that the remains on Flores island represented a new species of human, "Homo floresiensis", which was about 3-feet tall with brains roughly the size of grapefruits.
But in an article in the Proceedings of the National Academy of Sciences this week, a team led by Robert Eckhardt, professor of developmental genetics and evolutionary morphology at Pennsylvania State University, disputed those findings.
The international research team said only one reasonably complete skeleton, classified as "LB1", was unearthed and it probably belonged to an early human suffering from microencephaly, a condition where the head and brain are abnormally small.
Other skeletal parts were found in the cave, but no other cranial parts were unearthed.
"LB1 is not a normal member of a new species, but an abnormal member of our own," said Eckhardt.
Eckhardt's team said four major areas of evidence proved the 2004 evaluation wrong.
The 2004 theory asserted that early human ancestors traveled to the island about 840,000 years ago, evolved into the new species, and that there was no subsequent human migration to the island until they died out about 15,000 years ago.
But Eckhardt's team said this was false as pygmy elephants arrived on the island twice and during periods of low sea levels, Flores was isolated from other islands only by short distances.
This made "repeated influxes by later humans not only possible, but likely," it said.
The earlier team was also wrong to have compared the facial features of LB1 with those of homosapiens from Europe.
LB1's face was also exceedingly asymmetrical, pointing to an "abnormal developmental disorder", Eckhardt's team said.