2023-09-01 09:30:49
A team of researchers from China, Italy and the US has shed light on hitherto inexplicable data in the fossil record of Africa and Eurasia. Through a novel method named FitCoal (rapid coalescence process in infinitesimal time), the scientists were able to pinpoint demographic inferences from current human genomic sequences of 3,154 individuals.
Their conclusions suggest that the first human ancestors went through a long and severe bottleneck in which approximately 1,280 breeding individuals they were able to maintain a population for about 117,000 years.
Although this research has revealed some aspects of the ancestors early to mid Pleistocenethere are still many questions to be answered since this information was discovered.
genetic analysis
In this study, published in the journal Science, a large number of genomic sequences were analysed. However, “the fact that FitCoal can detect the old severe bottleneck with even a few sequences represents a great advance,” says the lead author of the scam, Yun-Xin Fua population geneticist at the University of Texas Health Science Center at Houston (USA).
The gap in the fossil records of Africa and Eurasia can be explained by this bottleneck in the early Stone Age.
Giorgio Manzi, anthropologist at the Sapienza University of Rome
The results obtained with this state-of-the-art methodology to calculate the probability of current genomic sequences suggest that the first human ancestors experienced an extreme loss of life and, therefore, of genetic diversity.
“The gap in the fossil records of Africa and Eurasia can be explained by this bottleneck in the early Stone Age. It matches this proposed time period of significant loss of fossil evidence,” he says. George Manzianthropologist from the Sapienza University of Rome (Italy).
adverse weather conditions
The suggested reasons for this ancestral population decline humans are above all climatic: the glaciations of this time caused changes in temperatures, severe droughts and the loss of other species, potentially used as food sources by ancestral humans.
It is estimated that 65.85 % of current genetic diversity could have been lost due to this bottleneck in the early and mid-Pleistocene, and the long period of minimum number of breeding individuals. threatened humanity as we know it today. However, it appears that it also contributed to a speciation event in which two ancestral chromosomes may have converged to form what is now known as chromosome 2 in modern humans. With this information, the last common ancestor of Denisovans, Neanderthals, and modern humans has potentially been discovered (A wise man).
An answer that opens other unknowns
It opens up a new field in human evolution because it evokes many questions, such as where they lived or how they overcame catastrophic climate changes.
Yi Gong, a scientist at Shanghai Ocean University
“The novel finding opens a new field in human evolution because it evokes many questions, such as where these individuals lived, how they overcame catastrophic climate changes, and whether natural selection during the bottleneck accelerated the evolution of the human brain,” he argues. Yi-Hsuan Panfrom East China Normal University who is also participating in the study.
Now that there is reason to believe that there was a lucha ancestral between 930,000 and 813,000 years ago for survival, researchers can dig further to find answers to these questions and to uncover how such a small population persisted under presumably difficult and dangerous conditions.
He fire controlas well as climate change towards a climate more hospitable to human life, could have contributed to a subsequent rapid population increase around 813,000 years ago.
Future goals are to sketch a more complete picture of human evolution during this transition period from the Early to Middle Pleistocene.
LI Haipeng, geneticist at the Chinese Academy of Sciences
“These findings are just the beginning. Future goals with these insights are to paint a more complete picture of human evolution during this transition period from the Early to Middle Pleistocene, which in turn will continue to unravel the mystery of ancestry and evolution.” early human evolution,” concludes LI Haipengtheoretical population geneticist and computational biologist at the Shanghai Institute of Nutrition and Health of the Chinese Academy of Sciences.
Reference:
Haipeng, LI et al. “Genomic inference of a severe human bottleneck during the Early to Middle Pleistocene transition”. Science.
Fuente: SINC
Rights: Creative Commons.
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