Relaxed Purifying Selection is Associated with an Accumulation of Transposable Elements in Flies.

#Transposons #PurifyingSelection #GenomeSize #GeneticDrift #EffectivePopulationSize #Flies #Drosophila

https://academic.oup.com/mbe/article/42/6/msaf111/8149079

Our new #preprint changes the way we look at an “extinction vortex” in which a small population loses fitness, causing it to become even smaller https://www.biorxiv.org/content/10.1101/2024.10.25.620329v1.
#MutationalMeltdown #EffectivePopulationSize #EvolutionaryRescue #PopulationGenetics #EvolGenPaper @wmawass @jdmatheson @uliseshmc 1/7

Our latest paper https://elifesciences.org/articles/87335
directly measures the #EffectivePopulationSize that matters to #NearlyNeutralTheory / #DriftBarrier theory, as the degree to which #CodonBias differs from expectations from GC content. Surprisingly, stronger #NaturalSelection -> higher #IntrinsicStructuralDisorder proteins
#MolecularEvolution #PopulationGenetics #EvolgenPaper 1/

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Paper now published in @GenomeBiolEvol https://academic.oup.com/gbe/article/16/3/evae050/7628489, details in preprint thread above. #BackgroundSelection #EffectivePopulationSize @jdmatheson

The neutralist-selectionist debate needs moderating, and this paper makes some good contributions, but ultimately disappoints. It defends #NeutralTheory as acknowledging #BackgroundSelection, but does not qualify that this is only a limited form of background selection - one with strong deleterious effects and Ud<1, such that background selection can be captured by a 1-locus model of random #GeneticDrift with lower #EffectivePopulationSize. https://onlinelibrary.wiley.com/doi/10.1111/brv.13010?af=R 1/n

Our preprint describes how #EffectivePopulationSize affects #AminoAcid usage. https://www.biorxiv.org/content/10.1101/2023.02.01.526552v2. Within highly exchangeable pairs of amino acids, high Ne species are able to prefer #arginine over #lysine, and #valine over #isoleucine. This matches #thermophile preferences, as expected from theories of marginal protein stability at mutation-selection-drift balance. 1/6
@hanonmcshea #NearlyNeutralTheory #MolecularEvolution #EvolgenPaper

Background selection at unlinked sites might not matter if it can be well captured by a lower #EffectivePopulationSize describing #GeneticDrift in a 1-locus idealized model. So we added a figure to demonstrate that this isn't the case. 6/5

Our latest #preprint develops a new metric of #CodonAdaptation (not just #CodonBias) to measure the kind of #EffectivePopulationSize that matters to #NearlyNeutralTheory, and uses it to discover that #NaturalSelection prefers high #IntrinsicStructuralDisorder https://www.biorxiv.org/content/10.1101/2023.03.02.530449v1 1/6
#MolecularEvolution #PopulationGenetics #EvolgenPaper

Our latest #preprint https://www.biorxiv.org/content/10.1101/2022.01.11.475913v2 @jdmatheson calls for significant change to the theory of #BackgroundSelection, a phenomenon by which some genomic segments of some individuals don’t count toward an #EffectivePopulationSize because they contain too many deleterious mutations. 1/5

#MolecularEvolution #PopulationGenetics #MutationLoad #EvolgenPaper