A controversial theory that a mysterious species known as hobbits were closely linked to modern humans has been ruled out by Australian scientists.
Hobbits, scientifically known as Homo floresiensis, were first discovered during an archaeological dig on the Indonesian island of Flores in 2003.
The species, which stood about 1-metre tall and weighed about 25 kilograms, was known to live in the area as recently as 54,000 years ago.
A major theory about their origin held that they descended from human ancestor Homo erectus, shrinking in stature over hundreds of generations.
However, a new study from the Australian National University (ANU), which analysed characteristics of the hobbit skeletons, found they were more likely descended from hominids in Africa and could be far older than predicted.
Professor Colin Groves, who worked on the study, said the species likely evolved from the older Homo habilis.
"The major controversy was over whether it was perhaps a pathological modern human ... I think that idea is dead," he said.
"We think it very unlikely that it was descended from Homo erectus, and in fact its sister species - that is the one it is most closely related to - is Homo habilis, which lived in Africa about 1.5 to 2 million years ago."
The study found several points of difference between Homo floresiensis skeletons and those of Homo erectus.
Study leader Debbie Argue said the structure of the Homo floresiensis jaw was inconsistent with that of Homo erectus.
"We looked at whether Homo floresiensis could be descended from Homo erectus," she said.
"Logically, it would be hard to understand how you could have that regression - why would the jaw of Homo erectus evolve back to the primitive condition we see in Homo floresiensis?"
Researchers said they were 99 per cent sure the species was not descended from Homo erectus, and could totally discount the theory that hobbits were malformed modern humans.