Publications

You can also find my articles on my Google Scholar profile.

Peer-Reviewed & Accepted

Assessing the impact of pedigree attributes on the validity of quantitative genetic parameter estimates Permalink

Published in Journal of Evolutionary Biology, 2025

Quantitative genetic inference from historical genealogies rests on pedigrees that were never designed for the purpose. This paper asks how their depth, completeness, and structure shape the parameter estimates we draw from them.

Recommended citation: Mawass, W., and Milot, E. (2025). "Assessing the impact of pedigree attributes on the validity of quantitative genetic parameter estimates." Journal of Evolutionary Biology, 38(4), 439–456.

Genotype-by-environment interactions modulate the rate of microevolution in reproductive timing in humans Permalink

Published in Evolution, 2022

A trait can be heritable and under consistent directional selection and still evolve at a rate that varies over time. This paper shows how genotype-by-environment interactions produce exactly that outcome in human reproductive timing.

Recommended citation: Mawass, W., Mayer, F. M., and Milot, E. (2022). "Genotype-by-environment interactions modulate the rate of microevolution in reproductive timing in humans." Evolution, 76(7), 1391–1405.

Extinction vortices are driven more by a shortage of beneficial mutations than by deleterious mutation accumulation Permalink

Published in Proceedings of the Royal Society B, 2026

Small populations are usually thought to spiral toward extinction because deleterious mutations accumulate. We show that the shortage of beneficial mutations — mutational drought — is the stronger driver over long timescales.

Recommended citation: Mawass, W., Hernández, U., Matheson, J., Berg, J. J., and Masel, J. (2026). "Extinction vortices are driven more by a shortage of beneficial mutations than by deleterious mutation accumulation." Proceedings of the Royal Society B, 293(2072), 20260600.

Preprints (Under Review)

Contrasting evolutionary outcomes in a human life history trait which is heritable and under consistent unbiased directional selection Permalink

Published in bioRxiv, 2025

If selection is consistent and the trait is heritable, replicate populations should evolve along similar trajectories. They do not. This preprint tests the consistency of evolutionary outcomes across replicate human populations.

Recommended citation: Mawass, W., and Milot, E. (2025). "Contrasting evolutionary outcomes in a human life history trait which is heritable and under consistent unbiased directional selection." bioRxiv, 2025.10.13.682154.

Quantifying the susceptibility of polygenic scores to ancestry stratification Permalink

Published in bioRxiv, 2025

Polygenic scores inherit whatever population structure the underlying GWAS failed to control. This preprint quantifies how susceptible they are, and what residual stratification does to downstream inference.

Recommended citation: Blanc, J., Mawass, W., and Berg, J. J. (2025). "Quantifying the susceptibility of polygenic scores to ancestry stratification." bioRxiv, 2025.12.04.692430.

Rare variants drive high variance in human ancestral fitness at mutation-selection-drift balance Permalink

Published in bioRxiv, 2026

At mutation-selection-drift balance, most of the variance in ancestral fitness traces to rare variants rather than common ones.

Recommended citation: Hernández, U., Mawass, W., Matheson, J., and Masel, J. (2026). "Rare variants drive high variance in human ancestral fitness at mutation-selection-drift balance." bioRxiv, 2026.07.29.741368.

Manuscripts in Preparation

Measured fitness variance is too weak to explain the missing diversity

In preparation — advanced manuscript available upon request

Mawass, W.

Published heritable fitness variances from 19 vertebrate populations are too small to explain observed diversity deficits, and at the same time too large to be maintained at equilibrium.

Evaluating bias in polygenic score associations due to imperfect control of population stratification

In preparation — advanced manuscript available upon request

Mawass, W., Blanc, J., Sherif, A., and Berg, J. J.

A random matrix theory treatment of what principal component correction can and cannot remove, and how the residual propagates into polygenic score associations.

High deleterious mutation rate distorts site frequency spectrum in mammals and leads to erroneous inference of demographic expansions

In preparation

Marcelle, M., Hernández, U., Mawass, W., Gutenkunst, R., and Masel, J.

Demographic inference assumes the neutral site frequency spectrum is shaped by demography. In mammals, a high deleterious mutation rate distorts it enough to manufacture expansions that never happened.

Information about the derived orientation of disease risk-increasing variants provides power to detect signals of directional selection on diseases

In preparation

Rial, K., Mawass, W., and Berg, J. J.

Knowing which allele is derived, not merely which raises risk, adds statistical power to tests for directional selection on disease traits.

Linked neutral diversity under stabilizing selection: a two-locus moments model

In preparation

Zhou, S., Mawass, W., Hayward, L., and Berg, J. J.

A two-locus moments framework for how stabilizing selection shapes diversity at linked neutral sites.

Walid Mawass

Publications

Peer-Reviewed & Accepted

Preprints (Under Review)

Manuscripts in Preparation