Thanks to my terrific students and colleagues who nominated me for the #SMBE2026 lifetime achievement award. You make science fun!

We are actively searching for a postdoc to join the lab! Details provided here - johrilab.org/join Please share. I will be at PEQG and will be happy to chat if you're interested!

New from @gvbarroso.bsky.social in our lab: quantifying the relative importance of mutation rate variation and background selection to levels of diversity along the human genome.

bioRxiv Evolutionary Biology@biorxiv-evobio.bsky.social · 2mo ago

Causal inference clarifies the roles of background selection and mutation rate variation in shaping human genetic diversity https://www.biorxiv.org/content/10.64898/2026.06.02.727906v1

Our preprint, where we infer the fitness effects of new mutations in regulatory regions of the D. melanogaster genome. We find an abundance of weakly deleterious effects - www.biorxiv.org/content/10.6... Led by @adaigle.bsky.social .

Population geneticists! Come work at 23andMe! New role just posted. 23andme.wd5.myworkdayjobs.com/23/job/Palo-...

A model for background selection in non-equilibrium populations https://www.biorxiv.org/content/10.1101/2025.02.19.639084v1

Happy International Women’s Day! We are grateful to the incredible women who lead (and have led) the Canadian Society of Ecology and Evolution, & to all the women ecologists & evolutionary biologists across Canada for their important work. You help make our society, country, & planet a better place!

In #GENETICS, Jacob Marsh, Sachin Kaushik, and @johriparul.bsky.social examine why and when rescaling of forward simulations in population genetics is not accurate, identifying pitfalls in simulation methods. buff.ly/wpzDRV9

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.

Homepage - 2026 Population, Evolutionary, and Quantitative Genetics Conference

Visit our website to learn more.

genetics-gsa.org

The last work of my PhD is finally out: www.pnas.org/doi/10.1073/...! This work is about accurately estimating branch length in the Ancestral Recombination Graph (ARG), which is achieved by a really simple framework with minimal assumptions. (1/n)

The SMBE Graduate Student Excellence Award honors the best presentation at the Graduate Student Excellence symposium, which provides a forum for young investigators to showcase their exemplary research at the annual meeting. 📨 Award applications smbe2026.org/abstracts #SMBE2026

We (with Fanny Pouyet and Brian Charlesworth) provide a theoretical perspective on rescaling forward simulations in population genetics, along with some guidelines: arxiv.org/abs/2601.05367

The rights and wrongs of rescaling in population genetics simulations

Computer simulations of complex population genetic models are an essential tool for making sense of the large-scale datasets of multiple genome sequences from a single species that are becoming increa...

arxiv.org

I wrote a short op-ed in @genetics-gsa.bsky.social G3 this month’s issue on missing data problems in population genomics that I’ve been thinking about for a couple of years. Lemme know your thoughts! Comments/suggestions/ideas welcome! doi.org/10.1093/g3jo...

The missing data problem in population genomics and statistical methods to address them

The “Missing Data” problem is prevalent across all statistical inference, owing to the “absence of some part of a familiar data structure” (Efron 1994). Po

doi.org

We wrote a perspective piece about important considerations when building an evolutionary baseline model for population genomic inference in the deadliest malaria parasite- Plasmodium falciparum. www.biorxiv.org/content/10.6...

Towards an evolutionary baseline model of Plasmodium falciparum for population-genomic inference

Malaria has caused over 15.7 million deaths in the 21st century and was responsible for ∼600 thousand deaths globally in 2023 alone. Although many effective antimalarial drugs have been developed and ...

biorxiv.org

A final new paper out from the lab, work from Steve Johnson, @joannarifkin.bsky.social & @stepheniwright.bsky.social We asked what maintains the striking variation in floral color, size, and shape within and among populations of Dame's Rocket, Hesperis matronalis

Color, size, shape: The drivers of floral variation in Hesperis matronalis (Dame’s Rocket)

Evolutionary biologists have long been intrigued by the factors that sustain genetic and phenotypic variation within and among natural populations. Polymorphisms underlying components of floral displa...

biorxiv.org

I'm on the Board of @biologists.bsky.social. Many know them as publishers of @dev-journal.bsky.social, @jcellsci.bsky.social, @jexpbiol.bsky.social , DMM, and @biologyopen.bsky.social --but they also are a major funder of small grants that empower young biologists and enable scientific meetings 🧪

The Company of Biologists@biologists.bsky.social · 8mo ago

We believe that, as our future leaders in biology, it is vital to provide #ECRs with the right support during the early stages of your academic career. We offer a number of practical ways to help you meet the unique needs and challenges you may encounter: www.biologists.com/about-us/ear...

Happy to highlight an essay I wrote together with @marcdemanuel.bsky.social, @natanaels.bsky.social and Anastasia Stolyarova, trying to think through what sets the mutation rate of a cell type in an animal species: www.biorxiv.org/content/10.6... 1/n

What sets the mutation rate of a cell type in an animal species?

Germline mutation rates per generation are strikingly similar across animals, despite vast differences in life histories. Analogously, in at least one somatic cell type, mutation rates at the end of l...

biorxiv.org

Now accepted in Genetics! academic.oup.com/genetics/adv... We ask why and when rescaling of forward simulations in population genetics is not accurate. There are some interesting results for people performing simulations with selection.

Effects of rescaling forward-in-time population genetic simulations

Abstract. Forward-in-time population genetic simulations enable modelling of a wide array of complex evolutionary scenarios. Simulating small genomic regio

academic.oup.com

The December episode of Genetics in Your World is now live!🎙️ ECS Multimedia Subcommittee member Debraj Manna interviewed Dr. Matthew Rockman (@wormsrock.bsky.social) of New York University about inbreeding depression in C. elegans. Listen now: buff.ly/7DVBt56

@lntran.bsky.social @castellanoed.bsky.social @ryangutenkunst.bsky.social introduce a systematic permutation approach for interpreting haplotype matrix-based methods in population genomics. 🔗 doi.org/10.1093/molbev/msaf250 #evobio #molbio

Interpreting Supervised Machine Learning Inferences in Population Genomics Using Haplotype Matrix Permutations

Abstract. Supervised machine learning methods, such as convolutional neural networks (CNNs), that use haplotype matrices as input data have become powerful

doi.org

The Johri Lab has an open postdoc position. Please send me an email, if interested. Start date is flexible. Please do share! Thank you in advance.

Our latest preprint about the effects of rescaling forward-in-time simulations in population genetics - www.biorxiv.org/content/10.1...

Excited to share my first PhD project with my mentor, @johriparul.bsky.social! We examine how Hill–Robertson interference (HRI) in highly selfing species biases estimates of the distribution of fitness effects of new mutations (DFE). doi.org/10.1093/evol... @journal-evo.bsky.social #popgen #evobio

Short thread on my updated work with @gutengroup.mcb.arizona.edu "Detection of Domestication Signals through the Analysis of the Full Distribution of Fitness Effects", latest version at: www.biorxiv.org/content/10.1... Here we simulate a kind of canonical and idealised domestication process.

Detection of Domestication Signals through the Analysis of the Full Distribution of Fitness Effects

Domestication is a process marked by complex interactions between demographic changes and selective pressures, which together shape genetic diversity. While the phenotypic outcomes of domestication ar...

biorxiv.org

Come join us in Tucson!! I am excited to announce a tenure track faculty position on the genomics of resilience @uofa-eeb.bsky.social! Read more about the position in the updated link below! We will begin reviewing applications on December 9! arizona.csod.com/ux/ats/caree...

Nominations due soon for the 2025 Dobzhansky Prize! This award recognizes the accomplishments and future promise of an outstanding early-career evolutionary biologist. Submit your nomination now! https://buff.ly/4fNJk9k