A Genomic Update on the Evolutionary Impact of Chromosomal Rearrangements

The field of evolutionary and speciation genomics has been revolutionised by the ubiquity and availability of genomic data even for non-model organisms. The capability to sequence long-fragment DNA has particularly spurred trans-national initiatives to generate publicly available chromosome-resolved reference genomes across the Tree of Life. Initiatives such as the Darwin Tree of Life (The Darwin Tree of Life Project Consortium et al. 2022) or the European Genome Atlas (ERGA; Mazzoni, Ciofi, and Waterhouse 2023) enable researchers around the globe to address unresolved questions and pursue novel lines of research. The role of chromosomal rearrangements (CRs) in driving evolution has been a long-standing question in evolutionary biology (Berdan et al. 2023; Dobzhansky and Sturtevant 1938; King 1995; Robertson 1916; Wellenreuther and Bernatchez 2018; White 1978). CRs comprise an array of rearrangements that reorganise the linear sequence of the genome, ranging from local structural variants (SVs) such as inversions or duplications, to large-scale karyological changes, including chromosomal fusions and fissions (Berdan et al. 2023; Lucek et al. 2023). Current genomic data have already highlighted that CRs are much more common and diverse across taxa than previously thought (e.g., Damas et al. 2022; Weissensteiner et al. 2020). While CRs can now more easily be mapped within and across taxa, their potential role for evolution and species diversification has often remained enigmatic, and theoretical explorations exist for only a few types of CR (Berdan et al. 2023). At the dawn of broad genome availability for model and non-model organisms alike, our special issue aims to provide a genomic update on the evolutionary impact of various types of CRs. Specifically, our special issue asks what causes the evolution and establishment of CRs and whether these causes differ among taxa? Are CRs randomly distributed across the genome, and do they cause other chromosomal rearrangements? How can CRs promote diversification and how do they potentially lead to speciation? Is the evolutionary impact of CRs the same among different types of CRs? Finally, do CRs have a different evolutionary impact depending on whether autosomes or sex chromosomes are involved?