A new model of human evolution suggests that Homo sapiens arose from many closely related populations rather than from a single group
A new model for human evolution Challenges the prevailing theories, and claims that Homo sapiens evolved from many diverse populations throughout Africa And not from one ancient population. This conclusion was reached after researchers analyzed genetic data from present-day African populations, including 44 new genomes from the Nama group in South Africa. The study suggests that the earliest detectable split in early human populations occurred 120,000 to 135,000 years ago, after long periods of genetic mixing, and that subsequent migrations created a weakly structured genetic stock. Contrary to some previous models, this study suggests that contributions from archaic hominins did not significantly affect Evolution of Homo sapiens.
In examining the genetic material of contemporary populations in Africa and comparing it to existing fossil evidence of populations Homo sapiens Early there, researchers uncovered a new model of human evolution - overturning previous beliefs that a single African population gave rise to all humans. The new study was published on May 17 in the journal Nature.
"Although it is known that Origin of Homo sapiens In Africa, uncertainty surrounds the question of how did the branches of human evolution diverge and how did people migrate across the continent?” said Brenna Hen, professor of anthropology at the University of California Davis Genome Center, who is the study's co-author.
"This uncertainty stems from ancient genomic data and a paucity of fossils, and from the fact that the fossil record does not always match expectations from models built using modern DNA," she said. "This new study changes the origin of species".
A joint study led by Hen and Simon Gravel from McGill University examined a variety of competing models of evolution and migration across Africa offered in the paleoanthropological and genetic literature, while integrating genome data from populations from southern, eastern and western Africa.
The authors included new genome sequencing from 44 modern individuals from South Africa, an indigenous population known to have extraordinary levels of genetic diversity compared to other modern groups. The researchers generated genetic data by collecting saliva samples from modern people going about their daily business in their villages between 2012 and 2015.
The model suggests that the earliest population split among early humans that can be discerned in contemporary populations occurred 120,000 to 135,000 years ago, after two or more weakly genetically differentiated Homo populations intermingled for hundreds of thousands of years. After the population split, people still migrated between the racial populations, creating a weakly structured race. This offers a better explanation of genetic variation between individual humans and human groups than previous models, the authors suggest.
"We're introducing something that people have never looked at before," Chen said of the study. "This significantly advances anthropological science."
"Previous, more complicated models suggested contributions from archaic hominins, but this model shows otherwise," said Tim Weaver, a professor of anthropology at the University of Davis. His area of expertise tries to answer the question of what early human fossils looked like and deals with comparative research.
The authors predict that according to this model, 1-4% of the genetic differentiation among contemporary human populations can be attributed to variation in the racial populations. This model may have important implications for deciphering the fossil record. Due to migration between the branches, these multiple lineages were probably morphologically similar, which means that morphologically different hominid fossils (such as Homo Neldi) are not expected to represent branches that contributed to the evolution of Homo sapiens, the authors said.
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