# Dissecting the genetics and evolution of complex traits using whole-genome genealogies

> **NIH NIH R35** · CORNELL UNIVERSITY · 2024 · $379,802

## Abstract

Project Summary
The Wei Lab develops accurate and scalable inference methods in population genetics and
statistical genetics. In the next few years, we will focus on understanding the evolution and
genetic basis of complex traits. Large biobank datasets with hundreds of thousands of human
genomes and tens of thousands of phenotypic measurements provide unprecedented
opportunities to understand complex phenotypes. At the same time, these massive data sets
demand more scalable and unbiased computational methods. My lab recently developed new
algorithms and data structures to improve the scalability of standard computations involving
genotype matrices, including the calculation of heritability components and linkage
disequilibrium scores. Our RSHE method runs 10-100x faster than the current state-of-the-art
method to allow heritability analysis on biobank-size whole-genome sequencing data. Further
methodological improvements will require new conceptualizations of the genotype-phenotype
relationships. Conventional statistical genetics uses genotype matrices directly, ignoring that
genetic polymorphisms are organized by gene genealogy into an interpretable graph structure.
Whole-genome genealogies can now be readily inferred using ancestral recombination graph
(ARG) inference software. Studying genealogy-phenotype relationships on ARGs could pinpoint
causal mutations, reduce multiple testing, promote algorithm efficiency, and integrate
evolutionarily meaningful models. We are developing a scalable algorithm for ARG-wide
association studies and will demonstrate its advantages even in the face of uncertainty in ARG
reconstruction. We will also develop fine-mapping methods on ARGs to study homogeneous
and admixed populations. Leveraging our RSHE code, we will implement a scalable method for
estimating heritability from ARGs and will apply this new method to the UK biobank to
understand why heritability estimated in unrelated individuals is lower than that from pedigree
analyses. Building upon this, we will implement a novel model parameterization to study
complex trait evolution using ARGs. Current polygenic adaptation papers all inevitably assume
that GWAS significant SNPs can be treated as causal variants and that different polygenicity
levels across phenotypes can be ignored. Our proposed method will provide the first rigorous
framework that takes these factors into account. In summary, this proposal will develop methods
to fully integrate ARGs into statistical genetics to better understand and conceptualize
phenotype-genealogy relationships. It will provide more scalable computational tools for the field
in response to the rapidly growing biomedical data and enable novel and more calibrated
discoveries for human disease genetics and phenotypic evolution.

## Key facts

- **NIH application ID:** 10890830
- **Project number:** 5R35GM150579-02
- **Recipient organization:** CORNELL UNIVERSITY
- **Principal Investigator:** Xinzhu Wei
- **Activity code:** R35 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2024
- **Award amount:** $379,802
- **Award type:** 5
- **Project period:** 2023-07-19 → 2028-05-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10890830

## Citation

> US National Institutes of Health, RePORTER application 10890830, Dissecting the genetics and evolution of complex traits using whole-genome genealogies (5R35GM150579-02). Retrieved via AI Analytics 2026-05-24 from https://api.ai-analytics.org/grant/nih/10890830. Licensed CC0.

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