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paoloferrari
07-24-2017, 05:59 PM
Polygenic Adaptation has Impacted Multiple Anthropometric
Traits


http://www.biorxiv.org/content/biorxiv/early/2017/07/23/167551.full.pdf

"Abstract
Most of our understanding of the genetic basis of human adaptation is biased toward loci of
large phenotypic effect. Genome wide association studies (GWAS) now enable the study of genetic
adaptation in highly polygenic phenotypes. Here we test for polygenic adaptation among 187 world-
wide human populations using polygenic scores constructed from GWAS of 34 complex traits. By
comparing these polygenic scores to a null distribution under genetic drift, we identify strong signals
of selection for a suite of anthropometric traits including height, infant head circumference (IHC),
hip circumference (HIP) and waist-to-hip ratio (WHR), as well as type 2 diabetes (T2D). In addition
to the known north-south gradient of polygenic height scores within Europe, we nd that natural
selection has contributed to a gradient of decreasing polygenic height scores from West to East
across Eurasia, and that this gradient is consistent with selection on height in ancient populations
who have contributed ancestry broadly across Eurasia. We nd that the signal of selection on HIP
can largely be explained as a correlated response to selection on height. However, our signals in
IHC and WC/WHR cannot, suggesting a response to selection along multiple axes of body shape
variation. Our observation that IHC, WC, and WHR polygenic scores follow a strong latitudinal
cline in Western Eurasia support the role of natural selection in establishing Bergmann's Rule in
humans, and are consistent with thermoregulatory adaptation in response to latitudinal temperature
variation"

Ebizur
07-25-2017, 03:59 AM
Polygenic Adaptation has Impacted Multiple Anthropometric
Traits

"Abstract
... In addition
to the known north-south gradient of polygenic height scores within Europe, we nd that natural
selection has contributed to a gradient of decreasing polygenic height scores from West to East
across Eurasia, and that this gradient is consistent with selection on height in ancient populations
who have contributed ancestry broadly across Eurasia. ... Our observation that IHC, WC, and WHR polygenic scores follow a strong latitudinal
cline in Western Eurasia support the role of natural selection in establishing Bergmann's Rule in
humans, and are consistent with thermoregulatory adaptation in response to latitudinal temperature
variation"They claim that their data reflect the operation of Bergmann's Rule in natural selection among humans in Western Eurasia, while also claiming that there is "a gradient of decreasing polygenic height scores from West to East across Eurasia." The climate in Eurasia (or in North America for that matter) is milder (less temperature variation, higher minimal temperature, etc.) toward the west and harsher (more temperature variation, lower minimal temperature, etc.) toward the east. Therefore, I wonder whether they have any data for pre-Russian indigenous peoples of Siberia, and how they compare in this regard to Northern Europeans, Southern Europeans, and more southerly populations of East and Southeast Asia.

Kale
07-25-2017, 06:04 AM
They claim that their data reflect the operation of Bergmann's Rule in natural selection among humans in Western Eurasia, while also claiming that there is "a gradient of decreasing polygenic height scores from West to East across Eurasia." The climate in Eurasia (or in North America for that matter) is milder (less temperature variation, higher minimal temperature, etc.) toward the west and harsher (more temperature variation, lower minimal temperature, etc.) toward the east. Therefore, I wonder whether they have any data for pre-Russian indigenous peoples of Siberia, and how they compare in this regard to Northern Europeans, Southern Europeans, and more southerly populations of East and Southeast Asia.

I'm assuming you don't live in North America. In New England (Northeast region) our temperature swings are ridiculous. In spring of this year there were days it was 80 degrees F (~27C) and there was still snow on the ground :P. Western Europe has ocean currents which mediate the temperature over the course of the year.

Ebizur
07-25-2017, 06:21 AM
I'm assuming you don't live in North America. In New England (Northeast region) our temperature swings are ridiculous. In spring of this year there were days it was 80 degrees F (~27C) and there was still snow on the ground :P. Western Europe has ocean currents which mediate the temperature over the course of the year.You apparently have misunderstood my comment. Please try reading it one more time.