A newly applied technique for analysing the ‘hobbit’ bones found on the Indonesian island of Flores strongly supports the theory that the remains come from a new species, potentially overturning longstanding ideas about human evolution and dispersal.
Anthropologist Debbie Argue from Australian National University has led a new research project comparing characteristics of Homo floresiensis bones to those of other early hominin species to build up a picture of where the hobbit sits in the evolutionary tree.
The team used ‘cladistic’ analysis – the first time this has been used in relation to H. floresiensis. It is an approach that compares the forms of organisms to determine ancestral relationships. The results – published in the Journal of Human Evolution – suggest that H. floresiensis diverged from the Homo sapiens evolutionary line in the Early Pleistocene, or even the Pliocene, nearly 2 million years ago, meaning that it did not share an immediate ancestor with modern humans.
“Until now much of the debate about H. floresiensis has rested on analysis of the morphology and measurements of the remains found on the Indonesian island of Flores in 2004,” Ms Argue said. “Despite evidence supporting the idea that H. floresiensis constitutes a new species, some researchers continue to argue that it is the remains of a sick modern human or a near-human ancestor affected by island miniaturisation.”
To try to settle the debate, Ms Argue and her colleagues compared up to 60 characteristics from a range of early hominins, including H. erectus, and modern humans. They used two different computer-based modelling systems, testing relationships between the species to find the most parsimonious, or simplest, evolutionary line.
“Our cladistic analyses created two very similar evolutionary trees that establish a very early origin for H. floresiensis back around the emergence of the very first members of the Homo family. This suggests that H. floresiensis was not a sick modern human, not even a very close relative.
Ms Argue said the findings support the idea that H. floresiensis constitutes a new hominin species – but it doesn’t stop there. The fact that the H. floresiensis population on Flores is a very early species suggests that hominins emerged from Africa much earlier than previously thought.
“The late survival of H. floresiensis on Flores could turn over the idea that H. sapiens was the only hominin around after the extinction of H. erectus and the Neanderthals,” Ms Argue said. “These two ideas represent paradigm shifts in the field of anthropology, forcing us to reconsider our long-held ideas about our species and its place in the world.”
The research team included Professor Mike Morwood from the University of Wollongong and researchers from the Indonesian Centre for Archaeology.
Editor's Note: Original news release can be found here.