العثور على جزء من فك و6 أسنان لإنسان إندونيسيا الأول عمره 700 ألف عام
عثر فريق من الباحثين الأستراليين على جزء من فك وستة أسنان لإنسان إندونيسى الأول - الذى يطلق عليه اسم "هوبيت" - يرجع تاريخهما إلى 700 ألف سنة، مما يدل على أن هذا الإنسان كان صغير الحجم ينتمى إلى قبائل لم تعش طويلا وتعرضت للاندثار، ليظهر الإنسان الحديث.
A 700,000-year-old hobbit has been discovered by a team of Australian-led researchers on the Indonesian island of Flores, shedding new light on human evolution.
The dwarf-like ancient relative of modern man stood just one metre tall and has been dated at half a million years older than a hobbit found on the island a decade ago.
Published in the journal Nature, the researchers argue their fossil find descended from Homo erectus, which would suggest an incredible case of evolutionary reversal where human bodies — including brains — actually shrunk.
كان العلماء قد اكتشفوا فى عام 2003 فى أحد الكهوف الإندونيسية، إنسان دى فلور- الذى عاش منذ 50 ألف عام - ولكن بعد العديد من الدراسات توصل العلماء أن هذا الإنسان قد اندثر منذ 16 ألف عام، وهو ما يؤكد هذا الكشف الجديد تأريخ اندثار هذا الإنسان الصغير إلى 700 ألف عام.
The University of Wollongong's Gert van den Bergh led the team who found the fragments.
He suggested that shrinking may have occurred because they were marooned on the island in a simple ecosystem with few predators, where perhaps they did not need such a big brain.
"But what is clear is that they made stone tools, so they weren't stupid," he said.
Found at a site called Mata Menge in central Flores, the jaw fragment and six teeth were from at least one adult and two children.
Griffith University archaeologist Adam Brumm described the island Flores as an experiment in natural evolution.
"There were earlier forms of humans that reached these islands — these were people that had technology, they had stone tools, they had the intelligence to make tools like our early ancestors.
"But that was not enough to protect their bodies from shrinking in size, just as occurred to elephants that also ended up in this remote island."
Dr van den Bergh said the discovery was significant because the fossils were much older than the previous hobbit find at Liang Boa, known as Homo floresiensis.
"The remains from Mata Menge, they are more than half a million years older than Homo floresiensis — almost 600,000 years older than the hobbit remains from Liang Boa," he said.
"We know that humans were present on the island 1 million years ago and that's based on dated stone artefacts."
By dating the layers of rock above and below the fossil find, researchers were able to work out the general age of the ancient discovery.
Homo floresiensis was discovered in 2004 — around the same time as the release of the Lord of the Rings movie trilogy — and has caused turmoil in the scientific community ever since.
"It was such a strange creature — only a metre tall with such a tiny brain and a mixture of primitive and advanced characteristics — and nobody really knew for sure what it was or what we should conclude," Dr van den Bergh said.
Dr van den Bergh said there were several hypotheses about the find, including that it was a dwarfed version of Homo erectus or that it came from a tinier, earlier ancestor like Homo habilis.
"The problem with that hypothesis was that those creatures have never been found outside Africa," he said.
"Now these new finds show that 700,000 years ago the ancestors of Homo floresiensis were already as small as the hobbit itself and secondly it provides a link between Homo erectus and Homo floresiensis."
An independent reviewer for the Nature journal, Aida Gomez-Robles from George Washington University's Department of Anthropology, backs the link between Homo erectus and Homo floresiensis.
"[However,] there is still a lot of debate about this," Dr Gomez-Robles said.
"Even if I think these fossils descended from Homo erectus, there are other people who think they are descended from Homo habilis."
One of the dissenting voices is ANU biological anthropologist Colin Groves, who believes there are not enough fossils to confirm a link to Homo erectus.
"I tend to be of the other school of thought, that thinks that it was descended from something like Homo habilis, which was a species that lived in Africa from about 2.3 to 1.4 million years ago," Professor Groves said.
"It was a small-sized species with a fairly small brain and rather idiosyncratic-looking teeth, relatively long arms, and short legs.
"It distributed itself around the tropical old world sometime after 2 million years ago — we don't know when — and eventually ended up on Flores about as far east as any pre-modern human did."
The only way to confirm the find is to find more fossils such as wrist bones and skulls, an exciting search that these researchers are more than ready for.
"There are many other islands in this region east of Bali and in between Asia and Australia that could contain early humans of entirely unknown forms, and no-one's even looked for the bones of these creatures," Dr Adam Brumm said.