In testing the genetic material of the current population in Africa and comparing it with the early extant fossil evidence Homo sapiens residents there, researchers have discovered a new paradigm for human evolution – overturning previous beliefs that a single African group gave rise to all humans. The new research is published in the journal Today, May 17 nature.
Although it is widely understood that Homo sapiens The uncertainty that originated in Africa surrounds how the branches of human evolution diverged and how people migrated across the continent, said Brenna Hinn, a professor of anthropology and the Genome Center at UC Davis, a corresponding author of the research.
“This uncertainty is due to limited fossil and ancient genomic data, and to the fact that the fossil record is not always in line with expectations from models built using modern DNA,” she said. “This new research changes the origin of species.”
The research, led by Henn and Simon Gravel of McGill University, tested a range of competing models of evolution and migration across Africa proposed in the paleoanthropology and genetics literature, incorporating population genome data from southern, eastern and western Africa.
The authors included newly sequenced genomes of 44 modern Nama individuals from South Africa, indigenous populations known to carry exceptional levels of genetic diversity compared to other modern groups. The researchers generated genetic data by collecting saliva samples from modern individuals going about their daily activities in their villages between 2012 and 2015.
The model suggests that the first population division among early humans that can be detected in the modern population occurred 120,000 to 135,000 years ago, after two or more weak genetic differentiations. to turn down The population has been mixing for hundreds of thousands of years. After the population split, people still migrate between stem groups, resulting in a poorly organized stem formation. The authors suggest that this provides a better explanation for genetic variation among human individuals and groups than previous models.
“We’re offering something people haven’t experienced before,” Henn said of the research. “This moves the anthropological sciences forward tremendously.”
“More complex previous models suggested contributions from ancient hominins, but this model suggests otherwise,” said co-author Tim Weaver, a UC Davis professor of anthropology. He has experience with the form of early human fossils and has provided comparative research for the study.
The authors predict that, under this model, 1–4% of genetic differentiation among modern humans can be attributed to variation in stem populations. This model may have important consequences for the interpretation of the fossil record. Because of migration between branches, these multiple lineages may have been morphologically similar, which means morphologically divergent hominid fossils (such as Homo naledi) is unlikely to represent branches that contributed to evolution Homo sapiensthe authors said.
Other co-authors include Aaron Ragsdale, University of Wisconsin, Madison; Elizabeth Atkinson, Baylor College of Medicine; and Eileen Hoall and Marlo Müller, Stellenbosch University, South Africa.