AsianScientist (May 2, 2017) – 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 as has been widely believed. These findings have been published in the Journal of Human Evolution.
The study by researchers at the Australian National University (ANU) found H. floresiensis, dubbed ‘the hobbits’ due to their small stature, were most likely a sister species ofHomo habilis—one of the earliest known species of human found in Africa 1.75 million years ago.
Data from the study concluded there was no evidence for the popular theory that H. floresiensis evolved from the much larger H. erectus, the only other early hominid known to have lived in the region with fossils discovered on the Indonesian mainland of Java.
Study leader Dr. Debbie Argue of the ANU School of Archaeology & Anthropology, said the results should help put to rest a debate that has been hotly contested ever since H. floresiensis was discovered.
“The analyses show that on the family tree, H. floresiensis was likely a sister species of H. habilis. It means these two shared a common ancestor,” Argue said.
“It’s possible that H. floresiensis evolved in Africa and migrated, or the common ancestor moved from Africa then evolved into H. floresiensis somewhere.”
H. 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.
“We looked at whether H. floresiensis could be descended from H. 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, H. floresiensis was more primitive than H. erectus.
“Logically, it would be hard to understand how you could have that regression—why would the jaw of H. erectus evolve back to the primitive condition we see in H. floresiensis?”
Argue said the analyses could also support the theory that H. floresiensis could have branched off earlier in the timeline, more than 1.75 million years ago.
“If this was the case H. floresiensis would have evolved before the earliest H. habilis, which would make it very archaic indeed,” she said.
Professor Mike Lee of Flinders University and the South Australian Museum, used statistical modeling to analyze the data.
“When we did the analysis there was really clear support for the relationship with H. habilis. H. floresiensis occupied a very primitive position on the human evolutionary tree,” Lee said.
“We can be 99 percent sure it’s not related to H. erectus and nearly 100 percent chance it isn’t a malformed H. sapiens.”
The article can be found at: Argue et al. (2017) The Affinities of Homo floresiensis based on Phylogenetic Analyses of Cranial, Dental, and Postcranial Characters.
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Source: Australian National University.
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