Dmitri Petrov

Excited to co-organize with @weieli.bsky.social a symposium at SMBE 2026 on how synthetic & systems biology can illuminate the molecular mechanisms of evolution. Honored to have @christianlandry.bsky.social as invited speaker! Join us!

This Saturday! Looking forward to hosting the Bay Area evolutionary, quantitative, and population genetics community at Stanford :)

OU College of International Studies professor reportedly arrested by ICE U.S. Immigration and Customs Enforcement reportedly arrested an OU professor at Will Rogers International Airport Saturday.

My colleague, Dr. Vahid Abedini, was illegally detained by ICE on Saturday. He is currently being held without a court date in sight, despite being in the country legally. Please spread the word! We must ensure his due process rights are upheld. www.oudaily.com/news/ou-prof...

An amazing paper! Give it a read - you won’t be disappointed.

Our new collaborative work led by @taliamycota.bsky.social
Jiajun Cui & Emma Caullireau between my lab @ucllifesciences.bsky.social @cloeucl.bsky.social & the Karasov Lab (tkarasovlab.org) @uofubiology.bsky.social
and collaborators: @plantricia.bsky.social et al.

tinyurl.com/5yx2wmz5

(1/n)

Registration for BAPG 2025, Stanford Dec 6 2025 Talk submissions are now closed, but poster submissions are still open.

Please note that we already have 130+ people signed up and we will limit the sign up at 160. Don’t dawdle If you want to attend. Registration is free but required. forms.gle/M5BSyAaeUggn...

Super excited about our schedule for BAPG at stanford on Dec 6. bapg2025.github.io/bapg2025stan... Amazing talks, a fabulous keynote, a lively poster session. A brilliant and interactive community. What’s not to love? 1/2 @sophiejwalton.bsky.social

So clever!

We have 115 people signed up already for BAPG! Great representation across career stages too. If you want to attend don't forget to sign up. It is free but required. @sophiejwalton.bsky.social and I are looking through the wonderful talk submissions and will announce the talks shortly. Stay tuned!

High-resolution mapping of a rapidly evolving complex trait reveals genotype-phenotype stability and an unpredictable genetic architecture of adaptation The extent to which adaptation can be predicted, particularly for traits with complex genetic bases, is unknown. Here, we leveraged a model complex trait, model species, and high-powered longitudinal ...

Thrilled to finally share the magnum opus of my PhD that focuses on the genetic basis of evolutionary change! Specifically, we know we can map the genetic basis of a trait, but can we tell which genes will underlie the trait shift when it evolves? doi.org/10.1101/2025...

Thank you to @skylerberardi.bsky.social, Jack Beltz, and Hayes Oken, for their beautiful and meticulous experimental work! And thank you to my advisors, both official and unofficial, @petrovadmitri.bsky.social and @paulrschmidt.bsky.social!

Big congratulations to @j-smiley-rhodes.bsky.social and @markcbitter.bsky.social and all other coauthors for truly monumental study and to my long-time collaborator and friend Paul Schmidt whose experimental orchard system keeps proving its incredible value in resolving thorniest of problems!

Super excited about this work! In brief, we can predict evolution of a trait if we use complete genetic mapping but individual loci often do idiosyncratic things and go in the opposite direction from the one based on the evolution of the trait itself. Very curious to know what you think! 1/2

My department at UT Austin is looking to hire an Assistant Professor in Evolutionary Biology, broadly defined. Feel free to reach out to me with any questions you may have.
apply.interfolio.com/177547

Yes! And also we have an exciting announcement - we are so lucky to have the privilege of having Brenna Henn give the keynote. hennlab.ucdavis.edu

don't forget to register for BAPG at Stanford on Dec 6! @petrovadmitri.bsky.social and CEHG are hosting. talk submissions close on Nov 16 - bapg2025.github.io/bapg2025stan...

docs.google.com/forms/d/e/1F...

Insertion of an invading retrovirus regulates a novel color trait in swordtail fish For over a century, evolutionary biologists have been motivated to understand the mechanisms through which organisms adapt to their environments. Coloration and pigmentation are remarkably variable wi...

I am so excited to share new work on a TE insertion that regulates iridescence in swordtails, led by fantastic grad student @nadiahaghani.bsky.social and with help from many coauthors! In a time that has been so difficult to navigate, this & other projects have kept my spirits up: shorturl.at/NE65A

Excited to share some new work led by grad student Sophie Walton (w/ @petrovadmitri.bsky.social). We used in vitro gut communities to study how natural selection acts on strains of the same species as they compete within larger communities. Check out Sophie's thread below for details!

An empirical approach to evaluating the prevalence of long-lived balancing selection in humans--and important limitations. Work by @hannahmm.bsky.social

Frequency-dependent fitness effects are ubiquitous In simple microbial populations, the fitness effects of most selected mutations are generally taken to be constant, independent of genotype frequency. This assumption underpins predictions about evolutionary dynamics, epistatic interactions, and the maintenance of genetic diversity in populations. Here, we systematically test this assumption using beneficial mutations from early generations of the Escherichia coli Long-Term Evolution Experiment (LTEE). Using flow cytometry-based competition assays, we find that frequency-dependent fitness effects are the norm rather than the exception, occurring in approximately 80\% of strain pairs tested. Most competitions exhibit negative frequency-dependence, where fitness advantages decline as mutant frequency increases. Furthermore, we demonstrate that the strength of frequency-dependence is predictable from invasion fitness measurements, with invasion fitness explaining approximately half of the biological variation in frequency-dependent slopes. Additionally, we observe violations of fitness transitivity in several strain combinations, indicating that competitive relationships cannot always be predicted from fitness relative to a single reference strain alone. Through high-resolution measurements of within-growth cycle dynamics, we show that simple resource competition explains a substantial portion of the frequency-dependence: when faster-growing genotypes dominate populations, they deplete shared resources more rapidly, reducing the time available for fitness differences to accumulate. Our results demonstrate that even in a simple model system designed to minimize ecological complexity, subtle ecological interactions between closely related genotypes create frequency-dependent selection that can fundamentally alter evolutionary dynamics. ### Competing Interest Statement The authors have declared no competing interest.

How common are frequency dependent fitness effects?

New preprint out today 👇
doi.org/10.1101/2025...

Kudos to our superstar grad student @sophiejwalton.bsky.social! One of the most interesting and surprising (at least to me) studies I have been involved in. Very curious to know what people think of it! @benjaminhgood.bsky.social

Super excited that the bulk of my PhD work is now preprinted! Here we used whole-community competition, or coalescence, experiments to quantify selection acting on genetically diverged strains within larger communities. (1/n)
www.biorxiv.org/content/10.1...

And of course thank you to @benjaminhgood.bsky.social and @petrovadmitri.bsky.social for mentoring me through this adventure. n/n

1/ Hello Drosophila-philists and braino-maniacs! 👋🪰🧠🧪

The Caron lab has a new preprint, and it is about 🥁🥁🥁 democracy!

Neuro-democracy, to be precise. So: drop EVERYTHING and listen up — a 🧶!

www.biorxiv.org/content/10.1...

Glass beads of all sorts balancing on wavy threads.

How is functional variation at large-effect loci maintained in natural populations, even as environments change? In a paper led by @mkarag.bsky.social, we tracked known pesticide resistant alleles in outdoor 𝘋. 𝘮𝘦𝘭𝘢𝘯𝘰𝘨𝘢𝘴𝘵𝘦𝘳 cages & inferred selection and dominance from temporal sequencing data.

Congratulations!!!

Faculty Position in the Department of Civil and Environmental Engineering and the Schwarzman College of Computing - cee.mit.edu The Department of Civil and Environmental Engineering (CEE), together with the Schwarzman College of Computing (SCC) at the Massachusetts Institute of Technology (MIT) in Cambridge MA, seeks candidate...

If you're looking for a faculty position at the intersection of ecology and computing (both broadly defined), please apply to this joint search between the CEE Department and the College of Computing at MIT: cee.mit.edu/people/share...

Home Hi, my name is James Kitchens, and I am a graduate student studying population genetics in the Coop Lab through the UC Davis Population Graduate Group.

Thank you James kitchens (james-kitchens.com) for the code that allowed @sophiejwalton.bsky.social to make the website!

Please register for BAPG at Stanford 12/6, especially if you want to give a talk or a poster. The deadline is Nov 16. bapg2025.github.io/bapg2025stan... And please reshare on bsky!

For sure!