Ryan Hernandez

Homepage - 2026 Population, Evolutionary, and Quantitative Genetics Conference Visit our website to learn more.

PEQG! My favorite conference ever*. Single session, fantastic talks, great discussions. Only once every 2 years. And in the best conference location too! Abstract deadline coming up Feb 5!

*Disclosure: I am required to say it's the best conference because it is and I told my mom I wouldn't lie.

The meeting will take place at the gorgeous IslandWood Resort on Bainbridge Island, a short ferry ride from downtown Seattle.

Registration is free. We will cover travel and lodging for graduate students, and at least partially subsidize those costs for postdocs and assistant professors.

Representation in genetic studies affects inference about genetic architecture Knowledge of a trait's "genetic architecture," namely the joint distribution of allele frequencies of causal variants and the direction and magnitude of their effects, is essential to understanding it...

Excited to share our new preprint from the @arbelharpak.bsky.social Lab!

How do recruitment into genetic studies and study characteristics impact what we infer about the genetic bases of traits, and what are the consequences? (1/21)

www.biorxiv.org/content/10.6...

High false sign rates in transcriptome-wide association studies Transcriptome-wide association studies (TWAS) are widely used to identify genes involved in complex traits and to infer the direction of gene effects on traits. However, despite their popularity, it r...

How well does TWAS estimate a gene’s direction of effect on a trait? We think of this as an important stress-test for the accuracy of TWAS.

In a new pre-print, we find that TWAS gets the sign wrong around 20-30% of the time!

doi.org/10.64898/202...

1/n

Portrait of Brenna Henn next to an open freezer of samples.

Here's my latest contribution to the @nytimes "Lost Science" series. Brenna Henn's sweeping study of African genetics has been frozen. Gift link: nyti.ms/3Ypmm1A

Oh come on… it is January SECOND. Who ALREADY broke our cluster?? #Wyntoff

🤯

This story is heartbreaking. Brenna Henn is a wonderful scientist, and the work their lab does is truly insightful. Anger and rage…

www.nytimes.com/2026/01/02/s...

Google's New AI Tool Can't Do Much. That's Exactly the Point Finally, an AI research tool that doesn't hallucinate papers

I'm usually skeptical about AI research tools. But Google's new tool for literature search is fantastic - because it does less, not more. New post:

substack.com/home/post/p-...

Putting on my hat as @asn-amnat.bsky.social ASN President for a minute for a string of announcements, please share widely!!!

1. Student research awards are open for applications, to fund research expenses for 10 graduate students ($2000 each)
nam10.safelinks.protection.outlook.com?url=https%3A...

Gene-specific selective sweeps are pervasive across human gut microbiomes - Nature Development and application of the integrated linkage disequilibrium score (iLDS) reveals both selective pressures impacting the human gut microbiome and the mechanisms by which gut bacteria adapt to ...

Grateful to share our paper on gene-specific selective sweeps in human gut microbiomes, now out in Nature! It has been a joy to work with @rwolff.bsky.social, whose insights and hard work made this possible.
www.nature.com/articles/s41...

Gene-specific selective sweeps are pervasive across human gut microbiomes - Nature Development and application of the integrated linkage disequilibrium score (iLDS) reveals both selective pressures impacting the human gut microbiome and the mechanisms by which gut bacteria adapt to ...

What a beautiful paper! www.nature.com/articles/s41...

Allele Frequencies at Recessive Disease Genes are Mainly Determined by Pleiotropic Effects in Heterozygotes The classic theory of mutation-selection balance predicts the equilibrium frequency of genetic variation under negative selection. The model predicts a simple relationship between the total frequency ...

Our latest preprint revisits the classic model of mutation-selection balance.

Do human recessive genes fit Haldane's 100-year old model?

This work is by the wonderful @jonj-udd.bsky.social, and co-mentored by @jeffspence.github.io

www.biorxiv.org/content/10.6...

Prediabetes remission and cardiovascular morbidity and mortality: post-hoc analyses from the Diabetes Prevention Program Outcome study and the DaQing Diabetes Prevention Outcome study Reaching prediatbetes remission is linked to a decades-long benefit, halving the risk of cardiovascular death or hospitalisation for heart failure in diverse populations. Targeting remission might rep...

Normalization of glucose in people with prediabetes, i.e. achieving remission, is linked to halving of major cardiovascular adverse events over ensuing decades
www.thelancet.com/journals/lan...

Event details: Wed, Jan 30 | 9 am–1 pm PT (12–4 pm ET), virtual via Zoom. Can’t attend? A senior postdoc can represent your lab. Follow‑ups encouraged.
Faculty deadline: Dec 10, 5 pm PT
Sign up: propelscholars.org/matchmaking-...

Why your time matters: Shrinking PhD cohorts and curtailed NIH Diversity Supplements mean fewer opportunities for strong applicants. Even a 10‑minute chat with faculty helps them hear the science, refine interests, and stay in the game.

Constraints are real: many campuses have hiring freezes, and exceptions are often possible. Funding can shift—today’s conversation can become a future match.

Unsure about hiring? Please join. The MME is a first step—not a commitment. Early conversations create options and keep pipelines moving.

Multi‑campus partnership: OHSU • UI • UCSF • UW–Madison • VCU. Join to meet top candidates across our network and build your pipeline of future scientific leaders.

Who are the scholars? Exceptional postbacs aiming for PhD/MD‑PhD/PharmD‑PhD—spanning a wide range of biomedical research interests (wet lab, computational, translational, clinical). Record interest: largest cohort yet (168).

What is the MME? A virtual, fast‑paced series of 10‑minute conversations where faculty meet recent grads for full‑time research roles and identify strong lab matches.

Faculty at OHSU, UIowa, UCSF, UW–Madison, and VCU: Your next amazing mentee could be one 10‑minute conversation away. PROPEL Virtual Matchmaking Event is Jan 30: 9–1 PT. Faculty registration deadline extended to 5pm PT on Wed Dec 10: propelscholars.org/matchmaking-...

"Prebunking works by exposing people to the techniques used to create misleading arguments before they encounter them in the wild."

Play on Princess Bride, converting ROUS (rodents of unusual size) to VOUS (variants of unknown significance).

Amazing to be at the #CAGI7 conference. As a data PRODUCER, no less! Fascinating discussions about variants of unknown significance, and how to get rid of them. Sad they are almost always acronymized as VUS, and only once was it VOUS.

My quote of the day

The probability that we may fail in the struggle ought not to deter us from the support of a cause we believe to be just.

Abraham Lincoln

A study on 1.7 million people in Hong Kong shows superior hybrid immunity to Covid in people who got vaccinated before infection vs. people who got infected first. "Our findings are a direct rebuttal to arguments for natural immunity," the authors write. doi.org/10.1016/j.va...

Did you publish with researchers outside your lab during grad school? Or published as faculty with a student not under your supervision?

I’m collecting examples of cross-lab collaboration in graduate training.

Please share your experience & this post!

Repository: bit.ly/4pT66BE

YouTube video by Erick Matsen Agentic Coding for Scientists (Dec 2025 edition)

The era of coding agents is here. How do we approach this as scientists?

Wednesday Dec 10th at 9am PT I'll livestream an interactive demo of what I have learned (matsen.group/agentic.html) about how to leverage agentic coding to do rigorous science.

www.youtube.com/watch?v=Rbhs...

"I love Slate! Everything is so intuitive and seamless!!"
- No grad program director or program manager I've ever met...

For those who attempted to submit your apps to PhD programs and have gotten strange errors, my apologies for the added stress... Folks are working hard to resolve issues!! 🤞🏽

I have a new preprint demonstrating a genome-architecture-aware approach to inferring species trees and introgression landscapes from a small number of genomes. If you are interested in phylogenomics, birds, or hybridization, this is for you! www.biorxiv.org/content/10.1...