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A Revised Model of Anatomically Modern Human Expansions Out of Africa through a Machine Learning Approximate Bayesian
Maria Teresa Vizzari1, Andrea Benazzo1, Guido Barbujani1
1Department of Life Sciences and Biotechnology, University of Ferrara, 44121 Ferrara, Italy.
Genes
|December 19, 2020
Summary
Anatomically modern humans (AMH) likely left Africa in two waves, not one. Genomic data suggests a multiple dispersal model is four times more probable than a single dispersal event.
Area of Science:
- Human Evolution
- Population Genetics
- Paleoanthropology
Background:
- Africa is widely accepted as the origin of anatomically modern humans (AMH).
- The exact dispersal routes and timing of AMHออกจาก Africa remain debated, with single vs. multiple wave hypotheses.
- Previous genetic studies have not definitively resolved these out-of-Africa dispersal models.
Purpose of the Study:
- To test the single vs. multiple dispersal models for anatomically modern humans (AMH) leaving Africa.
- To evaluate the efficacy of Approximate Bayesian Computation with Random Forests for distinguishing population history models.
- To compare simulated genetic data with real genomic variation from modern and archaic populations.
Main Methods:
- Utilized Approximate Bayesian Computation (ABC) coupled with the Random Forest algorithm.
- Simulated genetic data to assess the model's ability to differentiate between single and multiple AMH dispersal scenarios.
- Compared simulation outputs with genomic variation data from contemporary and ancient human populations.
Main Results:
- The study found that a multiple dispersal model is approximately four times more likely than a single dispersal model.
- Estimated two distinct dispersal events: one around 74,000 years ago and another around 46,000 years ago.
- The method successfully distinguished between the alternative out-of-Africa hypotheses.
Conclusions:
- Evidence strongly supports a model of multiple dispersals of anatomically modern humans (AMH) from Africa.
- The findings provide a refined timeline for key human migration events out of Africa.
- This research contributes to understanding the complex genetic history of human colonization.
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