Assortative mating and persistent reproductive isolation in hybrids

• DOI: 10.1073/pnas.1711238114
• Publication Date: 2017-10-03T00:40:29Z
• Authors: Molly Schumer; Daniel L. Powell; Pablo J. Delclós; Mattie Squire; Rongfeng Cui; Peter Andolfatto; Gil G. Rosenthal
• Keywords: Gene Flow; 0301 basic medicine; Genome; Reproductive Isolation; Whole Genome Sequencing; Genetic Speciation; Mating Preference, Animal; Biological Evolution; Cyprinodontiformes; 03 medical and health sciences; Animals; 14. Life underwater; Assortative mating; Hybridization; Population structure; Reproductive isolation

Significance Understanding the processes that generate or breakdown reproductive isolation between species is essential to understanding evolution. Assortative mating mediates reproductive isolation between species, but its dynamics in natural populations are poorly understood. Here we show that strong assortative mating maintains reproductive isolation in a natural hybrid population following an initial breakdown when the hybrid population formed, and strongly shaped the genetic structure of this population over ∼25 generations. Intriguingly, although in the wild these mate preferences result in nearly 100% of matings occurring between similar genotypes, this barrier breaks down in the laboratory. Our results highlight the importance of assortative mating in shaping hybrid population evolution and imply that short-term breakdown in assortative mating can have long-term evolutionary consequences.