Amelia Cervera 🧬Aug 12

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

Joanna MaselOct 30, 2024
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
Joanna MaselSep 6, 2024
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/
The protein domains of vertebrate species in which selection is more effective have greater intrinsic structural disorder

Proteins evolve more intrinsic structural disorder under more effective selection, with selection assessed via a novel metric of codon adaptation.

eLife
Show threadJoanna MaselMar 27, 2024
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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
Background Selection From Unlinked Sites Causes Nonindependent Evolution of Deleterious Mutations

Abstract. Background selection describes the reduction in neutral diversity caused by selection against deleterious alleles at other loci. It is typically

OUP Academic
Joanna MaselSep 9, 2023
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
Joanna MaselJun 15, 2023
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
Show threadJoanna MaselMar 18, 2023
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
Joanna MaselMar 4, 2023
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
Joanna MaselFeb 1, 2023

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