Genes showing adaptation across mammals also show adaptation in different populations

What is it about?

Detecting genes under adaptation represents a key step in the decoding of genomes. Several methods have been proposed, focusing either on the short time scale (population genetics, e.g., human populations) or on the long time scale (phylogenetics, e.g., across mammals). However, the accuracy of these methods is still under debate, and it is still unclear whether the signatures of adaptation are congruent across evolutionary scales. In this study, using phylogenetic methods and gathering genome data across and within species, we show that the signatures of adaptation at the phylogenetic and population- genetic scales can be reconciled. While providing a mutual confirmation of the two approaches, our work paves the way for further methodological integration between microevolutionary and macroevolutionary genomics.

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Photo by Jamie Haughton on Unsplash

Photo by Jamie Haughton on Unsplash

Why is it important?

Bridging the gap between micro-evolution (what shapes genetic variation within populations and how this contributes to short-term adaptation) and macro-evolution (how species have diversified and adapted to various environments) is still one major challenge of evolutionary sciences. This is particularly apparent in current bioinformatic methods for characterizing genetic adaptation: some of these methods focus on the short time scale (using population genetics, e.g., human populations), other on the long time scale (using phylogenies, e.g., across mammals), yet there is still a complete disconnect between them and thus far, they have not agreed with each other. In our study, we detect genes and sites that show adaptive signatures at the mammalian scale. Then we show that these genes and sites are also under adaptation in different populations (cow, goat, horse, sheep, dog, green monkey and human). While providing a mutual confirmation of the two approaches, our work paves the way for further methodological integration between microevolutionary and macroevolutionary genomics.