Ancestral polymorphisms explain the role of chromosomal inversions in speciation

• DOI: 10.1371/journal.pgen.1007526
• Publication Date: 2018-07-30T17:24:34Z
• Authors: Zachary L. Fuller; Christopher J. Le...; Randee E. Young; Stephen W. Schaeffer; Nitin Phadnis
• Keywords: Reproductive isolation; Drosophila pseudoobscura; Genetic algorithm; Chromosomal polymorphism; Chromosomal inversion; Incipient speciation; Coalescent theory; Lineage (genetic)

Understanding the role of chromosomal inversions in speciation is a fundamental problem evolutionary genetics. Here, we perform comprehensive reconstruction histories Drosophila persimilis and D. pseudoobscura. We provide solution to puzzling origins selfish Sex-Ratio arrangement uncover surprising patterns phylogenetic discordance on this chromosome. These show that, contrary widely held views, all fixed between pseudoobscura were already present their ancestral population long before species split. Our results suggest that higher genomic divergence an association reproductive isolation genes with may be direct consequence incomplete lineage sorting polymorphisms. findings force reconsideration speciation, not as protectors existing hybrid incompatibilities, but fertile grounds for formation.