Evolving Inversions. (March 2019)

• Record Type: Journal Article
• Authors: Faria, Rui; Johannesson, Kerstin; Butlin, Roger K.; Westram, Anja M.
• Is Part Of: Trends in ecology & evolution. Volume 34:Number 3(2019)
• Page Start: 239
• Page End: 248
• Publication Date: 2019-03
• Subjects: divergent selection -- balanced polymorphism -- heterosis -- speciation -- local adaptation -- genomic rearrangements; Ecology -- Periodicals; Evolution (Biology) -- Periodicals; 576.8
• DOI: 10.1016/j.tree.2018.12.005
• Languages: English
• ISSNs: 0169-5347

Abstract

Abstract : Empirical data suggest that inversions in many species contain genes important for intraspecific divergence and speciation, yet mechanisms of evolution remain unclear. While genes inside an inversion are tightly linked, inversions are not static but evolve separately from the rest of the genome by new mutations, recombination within arrangements, and gene flux between arrangements. Inversion polymorphisms are maintained by different processes, for example, divergent or balancing selection, or a mix of multiple processes. Moreover, the relative roles of selection, drift, mutation, and recombination will change over the lifetime of an inversion and within its area of distribution. We believe inversions are central to the evolution of many species, but we need many more data and new models to understand the complex mechanisms involved. Highlights: Empirical data suggest that many inversions are maintained polymorphic within populations by balancing selection, which impedes divergence and speciation. Contrary to earlier beliefs, we here argue that balancing and divergent selection may act together shaping the frequencies of inversions, maintaining many of them polymorphic, and having important consequences for adaptation and speciation. Inversions are not static but the derived and ancestral arrangements of an inversion continue to evolve, partly separately from each other and from the collinear genome, until lost or fixed. However, the evolution of inversions after their establishment is often neglected. New modelling approaches and data from additional taxa are needed to understand how inversions evolve over time and space, and what roles they play in adaptation, divergence, and speciation.