Bones show unexpected journey
Primitive ‘Hobbit’ from Indonesia is distinct from Homo erectus, study finds
Scientists have revealed new insights into a tiny ancient human nicknamed the Hobbit, which a Kiwi helped to discover. The most comprehensive study yet on the bones of Homo floresiensis has found that they most likely evolved from an ancestor in Africa and not from Homo erectus, as had been widely believed.
The late New Zealand archaeologist Professor Mike Morwood helped discover skeletal remains of the metre-tall species, known as Hobbit or Flores Hobbit, in a cave on the remote Indonesian island of Flores in 2003.
Since then, researchers have been trying to piece together the story of the intriguing creatures, investigating what it was that brought them to the island — and what caused them to vanish tens of thousands of years ago.
A new study by Australian and US researchers, just published in the Journal of Human Evolution, has now suggested the hobbits were most likely a sister species of Homo The Hobbit was set apart by its small body and brain size, receding forehead, short legs and large feet — hence the nickname. Scientists believe these quirky creatures would have used stone tools, hunted small elephants, vied with giant komodo dragons — and may have even used fire. habilis, one of the earliest-known species of human found in Africa 1.75 million years ago.
It follows another study published last year by international scientists, including the University of Auckland’s Associate Professor Brent Alloway, that used 700,000-year-old remains of what appeared to be the Hobbit’s ancestor to confirm them as an entirely separ- ate species, and not simply a deformed forebear of our race today.
Data from the new 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.
Study leader Dr Debbie Argue, of the Australian National University, said the results should help put to rest a debate that has been hotly contested ever since Homo floresiensis was discovered.
“The analyses show that on the family tree, Homo floresiensis was likely a sister species of Homo habilis,” she said. “It means these two shared a common ancestor.
“It’s possible that Homo floresiensis evolved in Africa and migrated, or the common ancestor moved from Africa, then evolved into Homo floresiensis somewhere.”
Homo floresiensis is known to have lived on Flores until as recently as 54,000 years ago.
A study grant enabled the researchers to explore where the newly found species fits in the human evolutionary tree.
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.
Argue said none of the data supported the theory that Homo floresiensis evolved from Homo erectus.
“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.
“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?”
Argue said the analyses could also support the theory that Homo floresiensis could have branched off earlier in the timeline, more than 1.75 million years ago.
“If this was the case Homo floresiensis would have evolved before the earliest Homo habilis, which would make it very archaic indeed.”
Professor Mike Lee of Flinders University and the South Australian Museum used statistical modelling to analyse the data.
“When we did the analysis there was really clear support for the relationship with Homo habilis.
“Homo floresiensis occupied a very primitive position on the human evolutionary tree,” Lee said.
“We can be 99 per cent sure it’s not related to Homo erectus and [there’s] nearly 100 per cent chance it isn’t a malformed Homo
sapiens.”