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DTSTART:20200329T030000
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DTSTART:20191027T020000
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DTSTAMP:20260404T203414Z
UID:5d760f6b49dea102605429@ist.ac.at
DTSTART:20191029T123000
DTEND:20191029T133000
DESCRIPTION:Speaker: Peter Visscher\nhosted by Nick Barton\nAbstract: Data 
 on trait-SNP associations can be leveraged to address questions of human a
 daptation\, selection on trait-associated loci and selection in contempora
 ry populations. We have used datasets from genome-wide association studies
  (GWAS) to address questions of (i) directional selection on loci associat
 ed with complex traits in Europe\, on a global scale and in isolated popul
 ations\, (ii) (apparent) stabilizing selection on multiple complex traits 
 in a contemporary population. If mutations with a large effect on a trait 
 are selected against (negative or purifying selection)\, irrespective of t
 he direction of the effect\, then the variance of effect sizes will be lar
 ger for SNPs with lower heterozygosity. We modelled association between he
 terozygosity and variance of effect size with a single (selection) paramet
 er in a Bayesian analysis\, and estimated it for tens of traits in a large
  dataset of more than 400\,000 individuals with trait and GWAS information
 . Our results suggest that natural selection has acted pervasively on loci
  associated with human complex traits but that selection coefficients at i
 ndividual loci are very small. Adaptation to extreme environments\, includ
 ing high altitude and populations separated by natural barriers (e.g. isla
 nds)\, appears driven by polygenic adaptation on standing variation in the
  ancestral population. In a contemporary population\, we find evidence of 
 phenotypic associations between lifetime reproductive success\, a proxy fo
 r fitness\, and multiple traits\, including educational attainment and sta
 ture\, consistent with both directional and stabilizing selection.
LOCATION:I22 Lakeside View (I22.01)\, ISTA
ORGANIZER:cfraisse@ist.ac.at
SUMMARY:Peter Visscher: Detection and quantification of the effect of selec
 tion and adaptation on human complex traits
URL:https://talks-calendar.ista.ac.at/events/2361
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