The fossil remains of between 1.78 and 1.95 million years, found in Kenya, solve many species of Homo existed.
A skull, a complete lower jaw and a fragment of a second lower jaw.These three fossil remains of between 1.78 and 1.95 million years, found in Kenya between 2007 and 2009, partially solved a question that haunted scientists for four decades ago: how many species of Homo lived in that time?The answer is that at least three species, according to the scientific team has found out the Koobi Fora Research Project (KFRP). A scientific team led by paleoanthropologist Meave Leakey, Turkana Basin Institute of Nairobi (Kenya), these illuminating results published in Nature.
The finding sheds light on an enigmatic species that existed at the dawn of the genus Homo, which exists only as Homo sapiens, about 2 million years. It also shows that there were several species of Homo in a time window of 1.78 to 2.03 million years in the Rift Valley, and probably coexisted together. Four decades ago, in 1972, Leakey discovered a mysterious fossil known as KNM-ER 1470 in Koobi Fora. It is a skull that is characterized by its large size and belonging to a face longer and flatter than other specimens attributed to the genus Homo. This fossil initiated a long debate about how many different species of Homo coexisted during the Pleistocene.
Some scientists attributed the unusual morphology of ‘1470 ‘to sex differences and natural variations within a species. It could be an unusual member of Homo habilis, which lived from 2.3 to 1.4 million years in East Africa. But his face did not match the flattening of habilis, with the upper jaw protruding, nor with that of our ancestor Homo erectus.
It reinforces the hypothesis of rudolfensis
Therefore, others interpreted the fossil as evidence of a new independent species, Homo rudolfensis. This would mean that the former group of modern humans was different. “It was always an anomaly. We knew we had to find more about it,” says Leakey. “Over the past 40 years we have ventured into the vast expanse of sediment around Lake Turkana in search of fossils to confirm the unique features of the face of ‘1470 ‘. We finally have some answers,” explains the researcher.
Experts believe that these new findings reinforce the hypothesis rudolfensis. According to the leader of the scientific analysis, Fred Spoor, Max Planck Institute for Evolutionary Anthropology in Leipzig (Germany), “the combination of the three new fossil provides a much clearer picture of what it was like ‘1470 ‘. It is now clear two of the first species of Homo coexisted with Homo erectus. “
Fossil skull found near ‘1470 ‘
The three new fossils were found within a radius of just over 10 miles of the location where you found the ‘1470 ‘and date between 1.78 million and 1.95 million years. The skull KNM-ER 62000, discovered in 2008, is very similar to ‘1470 ‘, but smaller, and shows that this disparity was not an individual unique. The new fossil retains the upper jaw with most of his teeth, allowing for the first time, to deduce the type of lower jaw had been set to ‘1470 ‘. Its small size discarded the old idea that the skull ‘1470 ‘corresponded to a male habilis.
Of the other two new fossil finds, the KNM-ER 60000 (found in 2009) stands out for its more complete lower jaw of the first members of the genus Homo discovered so far. Thanks to it now is known that the unusual taste rudolfensis had a U-shaped, with canine facing the front of the jaw, rather than the sides aligned in a V-shaped palate as Homo habilis. This suggests differences in the development of the two species, rather than variations within a species, according to Spoor.
The new fossils will be helpful to know how did our first branch of human evolution that flourished for nearly two million years. If three species coexisted in the same time and place, how they competed with each other for food and territory? William Kimbel paleoanthropologist from Arizona State University (USA), think that from now on will have to “formulate hypotheses to explain how they could have divided the space.”
The team working on this finding is made by Christopher Kiarie (TBI), who performed in the laboratory preparation of fossils, Craig Feibel of Rutgers University, who studied the age of fossils, and Susan Antón of the University of New York, Christopher Dean of University College London, Meave and Louise Leakey of Kenya TBI and Stony Brook University in New York, and Fred Spoor, Max Planck Institute for Evolutionary Anthropology (Leipzig) who analyzed the fossils. The field work was supported KFRP the National Geographic Society, which funded the KFRP since 1968.