Deadline for abstract submission, 25 April 2025:
eseb2025.com/call-for-abs...

Many thanks to the anonymous reviewers, and many more all co-authors Julien Joseph, Diego Hartasánchez and Nicolas Salamin.

8/8 Using exomes of 96 mammals with polymorphism data for 28 populations from 6 genera, we show that non-adaptive mutations constitute an important fraction of beneficial mutations (P[B₀|B]).

7/8 We then estimated the proportion of beneficial mutations that are not adaptive innovations among all beneficial mutations at the population scale.

6/8 We first estimated selective effects of mutations inside mammalian protein coding sequences, under a model assuming no adaptation at the phylogenetic scale.

5/8 Despite leaving similar signatures when looking only at populations, adaptive mutations promote phenotypic diversification (C) while non-adaptive mutations reduce diversity between species and stabilize existing systems (D).

4/8 Even though the existence of these beneficial yet non adaptive mutations is predicted by the nearly neutral theory (B), they have been largely overlooked, and positive selection has been often interpreted as adaptation to changing environments (A).

3/8 These mutations are then subsequently reverted by beneficial mutations, generating a balance at which genomes are constantly both “damaged” and “repaired” simultaneously at different loci.

2/8 Our study is based on the premise that slightly deleterious mutations scattered across the genome are reaching fixation due to genetic drift.

1/8 In this work based on genome-wide studies across mammalian species and populations, we estimated the proportion of beneficial mutations in protein coding sequences that are restoring pre-existing functions.