Washington. EFE .- A team of scientists placed the genus “Homo” 2.8 million years ago, 500,000 years earlier than previously thought, as revealed by the analysis of a hominid fossil found in a reservoir in Ethiopia, The results are published today in Science.
The discovery moves back the clock a few years of human evolution, since until now the oldest fossils of this genus, which owns modern man, dating from between 2.3 and 2.5 million years.
The researchers say the finding shows that the divergence of the genus “Homo” occurred earlier than had been completed, while indicating that more research is necessary to determine which species may belong.
The fossil, found in 2013 at the site Ledi-Geraru in the regional state of Afar (Ethiopia), is a partial jaw with five intact teeth, which as explained combines primitive features of ” Australopithecus “with more modern features of” Homo “.
The discovery took place a few miles from the area of Hadar, where in the seventies another team of researchers found” Lucy “skeleton” Australopithecus afarensis “fuller found so far, with a length of about 3.2 million years.
” Despite a lot of search, fossil lineage ‘Homo’ of more than 2 million years are very rare, “said Brian Villmoare, University of Nevada, one of the principal investigators, who at a press conference showed enthusiasm by the discovery team.
Villmoare and his team studied thoroughly jaw and found that, although age and place it fossil location near the “A. afarensis” rather their teeth coincides with the first species of “homo”, with thin molars, bicuspid and symmetric uniform proportions jaw.
The academic said the period covered between 2 and 3 million years is one of the most lakes have regarding the study of human origins, so “get an idea of the earliest phase the evolution of our lineage is particularly exciting. “
This finding hope it will help reduce the evolutionary gap between the” Australopithecus “and” Homo “.
” It’s an excellent example of a transitional fossil at a critical period in human evolution, “said William Kimble, a professor at Arizona State University and co-author of the study.
Moreover, the research department of geosciences Pennsylvania State University Erin DiMaggio leads another study in which geologically described the site where the jaw, which confirmed the age of the fossil was discovered.
The rocks and fossils vegetables are analyzing “shed light not allow only about a human lineage, but on the establishment of a geological environment in which lived the first ‘Homo’ ‘.
The team used various systems such as radiometric dating analysis of volcanic ash layers for determine the age of the sediments of the site.
“We are confident the age of LD 350-1,” said researcher on the fossil.
The geological evidence of the layer where The fossil was found LD 350-1 suggests that the environment was dominated by grasslands and shrubs, along rivers or wetlands. A scenario that would coincide with what is known of the region corresponding to that time, before it started to become drier.
What is to clarify the influence that could have a global climate change during this period and if there might be stimulated and new species extinctions, including the origin of “Homo”, something that has been hypothesized in the past.
“It’s still too early to say whether the change Climate is responsible for the origin of ‘Homo’ ‘he said in a note Kaye Reed, co-director of research at the University of Arizona, who added that this need “a larger sample of hominid fossils.”
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