Title: A Map of Recent Positive Selection in the Human Genome
Author: Benjamin F Voight, Sridhar Kudaravalli, Xiaoquan Wen, Jonathan K Pritchard
Scope: 3 stars
Readability: 2 stars
My personal rating: 4 stars
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Topic of Article
The authors apply new analytical methods to determine if humans have undergone significant genetic evolution within the last 10,000 years.
As this is a very technical article, I would not recommend reading it. I do think, however, that their findings are important to understand. Too many historical thinkers assume that human genetic evolution ended thousands of years ago, so they do not factor biology into their theories of why human societies changed.
- Human genes have undergone significant selection over the last 10,000 years.
- The amount and direction vary by region.
- The genetic changes substantially postdate the pre-historic migrations separated the populations.
Important Quotes from Article
The identification of signals of very recent positive selection provides information about the adaptation of modern humans to local conditions. We report here on a genome-wide scan for signals of very recent positive selection in favor of variants that have not yet reached fixation. We describe a new analytical method for scanning single nucleotide polymorphism (SNP) data for signals of recent selection, and apply this to data from the International HapMap Project. In all three continental groups we find widespread signals of recent positive selection. Most signals are region-specific, though a significant excess are shared across groups.
In summary, the selection events that we detect are generally very recent, substantially postdating the separation times of these populations, and falling mainly within the agricultural phase of human evolution.
These selective events are generally very recent, falling mainly within the Holocene era, and substantially postdating the separation of the three populations. Selective sweeps in Yoruba tend to be narrower and apparently older than in the non-African populations.
The tremendous shifts experienced by modern human populations in habitats, food sources, population densities, and pathogen exposures have surely led to direct selection pressures on medically relevant phenotypes. At least three of the regions that we identified as targets of selection have previously been associated with complex phenotypes, including CYP3A5 (salt-sensitive hypertension), ADH (alcoholism susceptibility), and the 17q21 inversion (recombination rates and fertility)