@wmawass
Evolutionary geneticist. I think about evolution across timescales and constraints on it from interactions at each scale. I use both population and quantitative genetics to do science. I love music, writing, and my cats (order varies on a daily basis).
Bottom line: detecting consistent selection and additive genetic variance does not guarantee an evolutionary response.
Our study highlights how even with selection + heritability, evolutionary stasis can persist.
🧬 Evolution isn’t always as predictable as we think!
Preprint: tinyurl.com/mr3r5vk3
Why? Several possibilities:
– Not enough time (7 generations)
– Small population size → drift
– G×E interactions constraining response
– Hidden life-history trade-offs limiting evolution
So what’s going on?
We see clear selection on a heritable trait, yet no evolutionary response.
This suggests that contemporary microevolutionary change is inconsistent and unpredictable — even under strong selection.
Using the Breeder’s Equation and the Robertson–Price covariance, we predicted evolutionary responses.
Only in Charlevoix did both models predict a strong response… that never happened.
In short: selection ≠ evolution, even when theory says it should.
Across cohorts, mean AFR changed differently across populations.
And when we looked at breeding values, there was no consistent genetic trend either.
(See figure — phenotypic vs. genetic patterns across time.)
relationship between fitness measure and age at first reproduction for the Charlevoix dataset
Our focal trait: age at first reproduction (AFR).
Linear models show strong directional selection favoring earlier AFR (see figure 👇).
Quantitative genetic models confirm that AFR is heritable (h² ≈ 0.11).
Yet—things get interesting.
We identified three subpopulations that can be considered semi-independent replicates: they share genetic and historical backgrounds and similar demographic histories as early French settlers spread across Québec.
(These pedigrees were validated in our earlier QG analyses.)
To tackle this, we needed longitudinal data with pedigree info to track phenotypic and genetic changes over time — in other words, replicated populations where quantitative genetic models are possible.
The historical French-Canadian (Québec) population turned out to be the perfect system.
Fellow evo-bio folks of BlueSky! 🧬
New preprint out — based on work from my PhD (yes, Chapter 3!) — where I ask:
👉 How predictable and consistent are evolutionary responses to selection in natural populations?
Preprint: tinyurl.com/mr3r5vk3 #evolution #microevolution #quantitativegenetics #preprint
One of my favorite posters among those I visited yesterday! Awesome graphics and color palette.
Excited for our publication on how the geographic scale of a sample affects the discovery of rare, deleterious variants to be out this week. With a mix of theory, simulation, and data analysis, we show when samples are narrow vs broad, the number of variants discovered and their frequencies change
Yikes!!!
We are excited to share our new preprint describing the inclusion of selection models to stdpopsim, our community-maintained library with an extensive catalog of population genetic models. 1/n
www.biorxiv.org/content/10.1...
Our latest paper revisits Haldane 1957 on speed limits to adaptation, the paper that triggered neutral theory. We clarify and then significantly extend the theory, and apply the resulting model to @mexpositoalonso.bsky.social's data doi.org/10.1093/gene... 1/14
This week’s Research-In-Progress meeting features Walid Mawass (@wmawass.bsky.social), postdoctoral scholar in the Berg Lab at the University of Chicago!
Research-In-Progress is a venue for the NITMB community to discuss planned or in-progress work
How does the quality of pedigrees impact genetic studies? Based on genealogical data, bigger and deeper pedigrees improve precision, but even small errors skew results! Our work highlights the need for careful sensitivity analyses:
doi.org/10.1093/jeb/...
@wmawass.bsky.social and E. Milot
I truly don't understand the whole "report on your work, or get fired". These people were EMPLOYED! They didn't go into the government saying "I'll be doing this job then". They applied to a job ad that DESCRIBES their job duties and they were HIRED because someone judged them to be a good fit 🤦🏾♂️
This is scary for the sheer illegality of these actions that the administration is taking and the jeopardy it puts people's life in! These employees can't even rely on their unions if the admin can just ignore unions outright!
www.reuters.com/world/us/us-...
🥳My work on the reliability of pedigrees used in quantitative genetic estimations of the genetic basis of phenotypic trait is out now in @jevbio.bsky.social! It also serves as a good intro for the use of pedigrees to infer genetic signals of phenotypes in populations
academic.oup.com/jeb/advance-...
This is good news! Even if not all demands were met, this is a clear demonstration of scientists ceizing the power to negotiate over compensation for their labor to the academic scientific enterprise. Add to it that the negotiations were with the government directly!
www.science.org/content/arti...
Easy one! Vice(2018)...Doesn't even need explaining for those who have seen it!
In my case, I would say it is "The Metamorphosis" by Franz Kafka.
Has anyone done research using data from human pops? I am trying to decide on a choice of representative figure for my paper. Should I pick one of the type of data (a picture of a civil act used to recreate social genealogies) or a picture of possible subjects of the human population in question?
It is without a doubt that academic research environments are shaping into a structured labor environment (grad researchers, postdoctoral researchers, staff scientists, principal investigators...). Therefore, it is no surprise that unionization is becoming prevalent.
We identified protein domains in LUCA (Last Universal Common Ancestor). Their distinctive amino acid usage reveals the order amino acids were added to the genetic code, based mostly on size. Older proteins hint at earlier alternative codes. 1/15 @seekingluca.bsky.social www.pnas.org/doi/10.1073/...
First layer of snow in Chicago! Hoping for snow to last a little longer this year than the last.
Hello🕺🏾!
I am recruiting graduate students this year to join my lab in Tucson! If you are interested in studying the evolution of plant diversity, polypoidy, and chromosomal evolution, please reach out about opportunities in my lab! Details about applying to EEB and our new CAMBIUM NRT in the thread below! 🧪
Saguaros and other Sonoran Desert plans stand in front of a purple and gray sky with a column of monsoon rain and rainbow in the distance.
If you are looking for a graduate program in Ecology & Evolutionary Biology, please considering joining us in Tucson, AZ! Our deadline is December 2 this year for admission to our Fall 2025 cohort. You can find out more about EEB and applying to our program here: eeb.arizona.edu/graduate/pro...
Beautiful scenes from the NZ parliament! It's more than just anti-colonialism...it is about showing the colonial vestiges that native practices are alive and well, and will continue to be employed as a sign of continuous resistance. Even inside of a parliamentary body!