jasonbertram

Mathematical biologist @WesternU Dept. of Mathematics. Ecology & evolution, population genetics.

[Geoff Wild @geoffwild]

[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!!
https://t.co/OIeWxm3wPG
https://t.co/mPd86DqngQ

[[email protected] @JoannaMasel]

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

[[email protected] @JoannaMasel]

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 https://t.co/ONFO3Bcmak 1/9

[jasonbertram @jason__bertram]

@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.

[jasonbertram @jason__bertram]

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

[jasonbertram @jason__bertram]

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 https://t.co/cKXOzMynYA. Thanks! 7/7

[jasonbertram @jason__bertram]

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

[evolvingseas @evolvingseas]

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!

[[email protected] @JoannaMasel]

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 https://t.co/H96DyF8NAq

[jasonbertram @jason__bertram]

@EcoEvoEvoEco A very delayed thanks for the reference!

[jasonbertram @jason__bertram]

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. https://t.co/cKXOzMynYA

[jasonbertram @jason__bertram]

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 (https://t.co/W6eBwy4ZHg). That study was a big influence on this one. Also thanks to @3rdreviewer for lots of great input.

[jasonbertram @jason__bertram]

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%.

[[email protected] @JoannaMasel]

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.