The publication of an analysis of human mitochondrial DNA in 1987 vaulted a classic model of human evolution, the out-of-Africa replacement (OAR), to become the dominant model of human evolution for a quarter of a century. This model posits that long after humans spread out of Africa into Eurasia at the Homo erectus stage, anatomically modern humans first evolved in Africa, expanded out of Africa into Eurasia sometime between 60,000 and 130,000. years ago, and completely replaced all the archaic human populations they encountered, driving them all to total genetic extinction. The genetic data were interpreted and presented as having falsified the multiregional model of human evolution in which modern humans had no single geographical origin because of gene flow (genetic interchange) among archaic populations. However, this falsification was based on a mistaken portrayal of the multiregional model as having little to no gene flow. Other models of human evolution were mostly ignored. Although much genetic data seemed to support the OAR model, in actuality, no genetic data set ever significantly favored the OAR model when placed into a hypothesis testing framework, and several genetic data sets and analyses strongly rejected or falsified replacement. Nevertheless, replacement remained dominant until the sequencing of ancient DNA provided direct confirmation that limited interbreeding, not complete replacement, had occurred, as had been inferred through hypothesis testing many years earlier. Ignoring the results of rigorous hypothesis testing still plagues the area of human evolution, particularly in the common portrayal of human "races" as separate branches of an evolutionary tree of human populations even though the hypothesis of a tree of human populations has been strongly rejected by all tested data.
|Title of host publication||On Human Nature|
|Subtitle of host publication||Biology, Psychology, Ethics, Politics, and Religion|
|Number of pages||19|
|State||Published - 2017|
Bibliographical notePublisher Copyright:
© 2017 Elsevier Inc. All rights reserved.
- Gene flow
- Human evolution
- Population trees
ASJC Scopus subject areas
- Agricultural and Biological Sciences (all)
- Biochemistry, Genetics and Molecular Biology (all)