For quite some time (several decades), scientists have been trying to determine when and in what way the genus Homo, our lineage of men, differentiated itself to begin the complex evolutionary process that ended in the humans that we are today. Now, an international team of researchers has made a crucial discovery for the clarification of this issue that concerns us so much: a fossil of a hominid that is 2.8 million years old .
This discovery published in the journal Science , which makes this fossil the oldest ever found , places the first “Homo” almost half a million years earlier than previously thought. The fossil in question, a partial jaw with five of its teeth still intact, was found in 2013 at the Ledi-Geraru site in the Afar regional state of Ethiopia.
According to the analyzes, the fossil combines the primitive features of Australopithecus with the more modern characteristics of Homo , which would place this genus a little earlier in time. It is a mandible proportioned with small molars and symmetrical premolars.
“Despite a lot of searching, fossils of the Homo lineage of more than 2 million years are very rare”, clarifies Brian Villmoare of the University of Nevada (USA) and co-author of the study. And it is that the period that covers between 2 and 3 million years is a sea of questions regarding the origins of man for the scientific community, “so having an idea of the earliest phase of the evolution of our lineage is particularly exciting, ”Willmoare continues.
To calculate the age of the fossil, the researchers used different dating systems , such as radiometric analysis of the volcanic ash layers to determine the age of the sediments in the deposits, which has also revealed that the environment was full of large grasslands and shrubs . lakes, rivers, active volcanoes and accompanied by prehistoric antelopes and elephants, ancestral types of hippos or crocodiles and fish, dating back between 2.8 and 2.5 million years.
