jasonbertram

[Pls RT] @westernuMath is hiring two tenure-track positions: one with data-science focus and another broadly defined. Come join a great dept and a growing collection of #mathbiol folks. Some of you may wish to apply to both!! mathjobs.org/jobs/list/20280 mathjobs.org/jobs/list/20281

I'm looking to hire a math-bio postdoc, to start ASAP. Project: make better models of density-dependent selection, improve the conceptual basis for trait classification, and help resolve the Grime-Tilman debate of ecology. Philosophy interest a bonus! @Project_Telos 1/4

Our latest preprint clarifies @JBS_Haldane's arguments about the cost of selection / substitutional load / selective deaths, and applies the surviving concepts to data @JosephMatheson2 @MExpositoAlonso doi.org/10.1101/2021.1… 1/9

@emydoid Yes, I think it would be hard to argue for neutrality in these fly systems in my view. The latter: it's probably the case that the extreme frequency mutations are experiencing even more selection from being bombarded by deleterious mutations but harder to detect.

Allele frequency divergence reveals ubiquitous influence of positive selection in Drosophila. #TempGen2021Tweets Temporal genomic data let us directly see evolution unfolding but hard to analyze. Today I’ll talk about detecting selection using allele frequencies (AF) 1/7

Only need AFs at two time points for many variants (ideally millions). Basic idea is a straightforward application of the law of total variance. Works for any offspring distribution (including high fecundity marine spawners). For more see biorxiv.org/content/10.110…. Thanks! 7/7

Can estimate the strength of selection underlying observed elevated variance: implies effective strength of selection |s|~1% for most SNPs, including neutral SNPs (in which case s represents linked selection). Represents a polygenic selective shift across most of the genome! 6/7

The schedule for #TempGen2021Tweets Twitter symposium is set!! Tune-in tomorrow from 9-2 ET and "listen" to @jason__bertram, @rebekahoomen, @paigebyerly, @emydoid, @AliceManuzzi, @ewers_saucedo, @NicolasLou10, & @EGarciaResearch present work on flies, sharks, seabirds and more!

Come do a postdoc with me, modeling mutation load, complexity ratchets, reproductive compensation, better models of absolute fitness and modular epistasis and/or mutation rate evolution evol.mcmaster.ca/~brian/evoldir…

@EcoEvoEvoEco A very delayed thanks for the reference!

@jason__bertram jason - I haven't read your paper yet but check out our new paper in Mol Ecol - onlinelibrary.wiley.com/doi/10.1111/me…

My latest, a (hopefully) fresh take on the short-term influence of selection. The idea: selection perturbs the divergence over time of an allele cohort starting at the same frequency. You can use this to extract truly “polygenic” signatures of selection. biorxiv.org/content/10.110…

This approach is similar in spirit to the nifty covariance approach of @vsbuffalo and @Graham_Coop in that it studies allele frequencies as a collective (pnas.org/content/117/34…). That study was a big influence on this one. Also thanks to @3rdreviewer for lots of great input.

So variance Ne is frequency dependent! Setting aside possible Ne rants, this frequency dependence can be put to good use to estimate the intensity of linked selection. I found typical total selection coefficients (measuring linked selection) had magnitudes of order 1%.

I'm looking for a postdoc to work with me on mutation load theory, ie why aren't we all dead a hundred times over. Maybe soon another one for protein evolution work. Email me for details if interested.