# Natural selection in recent human evolution

> **NIH NIH R01** · COLUMBIA UNIV NEW YORK MORNINGSIDE · 2020 · $389,574

## Abstract

PROJECT SUMMARY
Our understanding of natural selection in humans has been limited to indirect statistical inferences and
experiments in distantly related model organisms or in cell lines. We propose a new approach: to identify loci
that currently affect survival to a given age (i.e., viability), by mining the huge biomedical data sets now
available. Our idea is to look for variants and sets of variants that change frequency over birth cohorts and
generations more than expected by chance. Aim 1: We will identify variants that impact survival using
genetic data from large cohort studies. We plan to examine changes in allele frequencies across birth
cohorts, in >1 million individuals genotyped or resequenced genome-wide, starting with >200,000 genotypes
from GERA and the UK Biobank. Controlling for population structure, we will assess (i) if allele or genotype
frequencies change more with age than expected by chance; (ii) if the trends differ by sex; and (iii) if there is
evidence for a trade-off between effects at young and old ages. We will perform these tests for single loci
throughout the genome, as well as all loci in a given annotation (e.g., putatively damaging amino acid
mutations). To examine current selection pressures on quantitative traits, we will consider sets of variants
previously associated with over 40 quantitative traits (e.g., diabetes risk or height) and ask how the polygenic
score for each varies with age and sex. Aim 2: We will identify variants that influence survival to
adulthood or transmission odds in trio data. We propose to test for the unequal transmission of alleles
from heterozygous parents to surviving children or young adults in >35,000 trios that have been genotyped or
resequenced genome-wide. This data set provides high power to detect even moderate effects of selection
acting early on in life (at haploid or diploid life stages) and subtle cases of meiotic drive. We will consider males
and females separately as well as jointly, testing for distortion at each SNP and each haplotype block. We will
also examine sets of loci that contribute to the same quantitative phenotype. Aim 3: We will relate current
genetic variation to long-term selection pressures. By extending a statistical model that we recently
developed, we will assess whether the set of variants that influences susceptibility to a given disease or
anthropomorphic trait is enriched for signatures of positive, negative or balancing selection. This approach will
allow us to ask: (i) Which selective pressures, if any, have influenced any of over 40 quantitative phenotypes for
which we have collated mapping results; and (ii) Whether loci that currently affect development and aging
(identified in Aims 1 and 2) show signals of balancing or purifying selection. In a separate analysis, we will
examine which quantitative traits have contributed to local adaptation since human populations split. This
research will help to identify variation that influences developme...

## Key facts

- **NIH application ID:** 9840910
- **Project number:** 5R01GM121372-04
- **Recipient organization:** COLUMBIA UNIV NEW YORK MORNINGSIDE
- **Principal Investigator:** MOLLY F PRZEWORSKI
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $389,574
- **Award type:** 5
- **Project period:** 2017-03-08 → 2022-12-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9840910

## Citation

> US National Institutes of Health, RePORTER application 9840910, Natural selection in recent human evolution (5R01GM121372-04). Retrieved via AI Analytics 2026-05-22 from https://api.ai-analytics.org/grant/nih/9840910. Licensed CC0.

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