Selective Sweeps Lead to Evolutionary Success in an Amazonian Hyperdominant Palm

• Published in: Frontiers in genetics Vol. 11; p. 596662
• Main Authors: Melo, Warita A., Vieira, Lucas D., Novaes, Evandro, Bacon, Christine D., Collevatti, Rosane G.
• Format: Journal Article
• Language: English
• Published: Switzerland Frontiers Media S.A 23.12.2020
• Subjects: adaptation; adaptive trait; Arecaceae; Biologi; Biological Sciences; complex; DNA-sequence; Genetics; Genetics & Heredity; genomics; history; local adaptation; Mauritia flexuosa; neutral evolution; Population Genomics; population-genetics; single nucleotide polymorphism; software; target sequence capture; Arecaceae; neutral evolution; adaptation; Population Genomics; target sequence capture; Mauritia flexuosa
• DOI: 10.3389/fgene.2020.596662
• ISSN: 1664-8021

Despite the global importance of tropical ecosystems, few studies have identified how natural selection has shaped their megadiversity. Here, we test for the role of adaptation in the evolutionary success of the widespread, highly abundant Neotropical palm Mauritia flexuosa. We used a genome scan framework, sampling 16,262 single-nucleotide polymorphisms (SNPs) with target sequence capture in 264 individuals from 22 populations in rainforest and savanna ecosystems. We identified outlier loci as well as signal of adaptation using Bayesian correlations of allele frequency with environmental variables and detected both selective sweeps and genetic hitchhiking events. Functional annotation of SNPs with selection footprints identified loci affecting genes related to adaptation to environmental stress, plant development, and primary metabolic processes. The strong differences in climatic and soil variables between ecosystems matched the high differentiation and low admixture in population Bayesian clustering. Further, we found only small differences in allele frequency distribution in loci putatively under selection among widespread populations from different ecosystems, with fixation of a single allele in most populations. Taken together, our results indicate that adaptive selective sweeps related to environmental stress shaped the spatial pattern of genetic diversity in M. flexuosa , leading to high similarity in allele frequency among populations from different ecosystems.