Le Monde | • Updated | By
This is a good win, posthumously, for the Australian paleoanthropologist Michael Morwood. Died in 2013, it is the main party to two articles published on Thursday, June 9 in the journal Nature , which give reason: the man of Flores, aka “the hobbit”, he was discovered in 2003 in a cave in this Indonesian island, was not a Homo sapiens dwarf, suffering from microcephaly or other conditions that might explain the small size of his skull. This little man of just over one meter tall belonged good as he was convinced, a full species. She remained on the island for several hundred thousand years. – Until his death there about 50 000 years
The work published in Nature show by effect of new fossils – a fragment of right lower jaw and six teeth – late 2014 found on another site dating back 700 000 years. They show that a small humanity (the nickname borrowed novels characters from Tolkien) was already present on site so that Homo sapiens had not yet emerged in Africa!
“The paleoanthropology is again facing a major upheaval”
Gerrit van den Bergh (University of Wollongong, Australia) who led the excavations in the bed of an ancient river, the site of Mata Menge, chose Michael Morwood sedimentary layers that were most likely to deliver the remains of hominids. “ My only regret is that Mike did not live to share the experience and excitement of the discovery of these new fossils. We both knew that they had to be there , he said. I think he would have liked that paleoanthropology is again facing a major upheaval. “
The signatories of Articles Nature are careful prudent to assign the new fossils in a particular case, including Homo floresiensis , but their arguments led to this conclusion. “All these fossils are undoubtedly hominins and are remarkably similar to Homo floresiensis, said Yousuke Kaifu (National Museum of Science and Nature Tokyo), who compared them to an extensive collection of fossils and modern human skeletons. The morphology of the teeth also suggests that the human line represents a dwarf descendants of Homo erectus that, one way or another, found themselves isolated on Flores Island . “
this is most surprising to the researchers, is that the new mandible is still smaller than those found in 2003 in the cave of Ling Bua, a distance of 74 km. This implies that the size reduction has occurred very early in the history of this line. Indeed, the oldest tools found to date in Flores Island date back a million years, and are usually attributed to the Homo erectus , present in Asia in that period, and greater stature (just over 1.50 m high). The reduction in size would be given during the first 300,000 years of the occupation of the island.
Hunt stégodons dwarf
If the man Flores is the first example of island dwarfism affecting the human species, the phenomenon is well known for many other animals. “This size change mechanism is in both directions says paleoanthropologist Antoine Balzeau ( National Museum of natural history) : in the islands, where there is less food available, large carnivores are disappearing. The prey of small carnivores grow to escape them, and large animals shrink to deal with food restriction. “ This size selection by the appetite of each other that we find fossil dwarf elephants in the Mediterranean islands, for example. It took only six thousand red deer Jersey to see their size reduced by six from the ancestral population. Flores and even Homo floresiensis and its ancestors hunted dwarf stégodons, cousins of the elephant. And was found in the cave hobbit fossil remains of giant marabou.
Jean-Jacques Hublin (Max Planck Institute evolutionary anthropology in Leipzig), which was a time doubted the humanity of Homo floresiensis one “is certainly a descendant of Homo erectus who reached the island of Flores there are over a million years. There are 700,000 years, and probably much earlier, the effects of island dwarfism were felt on these isolated populations. It is unique among primates. Homo floresiensis then appears to have changed little from the size point of view as that of its lithic productions. “
Antoine Balzeau shares this: ” Think they go down to Homo erectus not to Homo habilis, that knows that in Africa, is the most parsimonious hypothesis. This second site, very old, gives a perspective of 700,000 years, a lot of depth to the discovery of this line. “ If the hobbit has generated so much skepticism on the part of a fringe of the scientific community, who wanted at all costs to see him as a medical anomaly rather than a new species, but also for cultural reasons, he analysis: “Imagine that a recent man could at this point be influenced by its environment was contrary to our vision sapiens as master of the world. The idea that brain size determines intelligence also played some not thinking it could make tools. “ New analyzes show, however, that the small brain of Homo floresiensis is in the intra-species variability observed in other animals. And Articles “pathologizing” Flores man hardly resisted the analysis. Antoine Balzeau had thus shown in February, with the forensic Philippe Charlier, the internal morphology of its skull showed no abnormalities known in Homo sapiens . On June 8, in PLOS ONE, is the thesis of trisomy 21, which is under attack.
The origin of these little men yet still keeps a bit of mystery. “The question is by what means Homo erectus came to Flores in the company of a few other vertebrate species,” asks Jean-Jacques Hublin. The end of the story seems less enigmatic: we lose track of the hobbit when Homo sapiens arrived in the area, there are about 50 000 years. The Lilliputian did not survive this Goliath …
Read also: The “Man of Flores,” aka the “Hobbit” would have gone much earlier than is thought
No comments:
Post a Comment