Genetic architecture influences when and how hybridization contributes to colonization

Abstract

<jats:title>Abstract</jats:title><jats:p>The role of genetic architecture in adaptation to novel environments has received considerable attention when the source of adaptation variation is <jats:italic>de novo</jats:italic> mutation. Relatively less is known when the source of adaptive variation is inter- or intraspecific hybridization. We model hybridization between divergent source populations and subsequent colonization of an unoccupied novel environment using individual-based simulations in order to understand the influence of genetic architecture on the timing of colonization and the mode of adaptation. We find that two distinct categories of genetic architecture facilitate rapid colonization but that they do so in qualitatively different ways. For few and/or tightly linked loci, the mode of adaptation is via the recovery of adaptive parental genotypes. With many unlinked loci, the mode of adaptation is via the generation of novel hybrid genotypes. The first category results in the shortest colonization lag phases across the widest range of parameter space, but further adaptation is mutation limited. The second category takes longer and is more sensitive to genetic variance and dispersal rate, but can facilitate adaptation to environmental conditions which exceed the tolerance of parental populations. These findings have implications for understanding the origins of biological invasions and the success of hybrid populations.</jats:p>

Chromosome-scale reference genome and RAD-based genetic map of yellow starthistle (Centaurea solstitialis) reveal putative structural variation and QTLs associated with invader traits

“…It is perhaps not surprising that QTL are associated with both of the large inversions that we inferred from our genetic map and reference genome, given that any trait loci in these chromosomal regions will be linked to the entire inversion. Nevertheless, loci that have large phenotypic effects - such as inversions containing many tightly linked genes affecting a trait - are predicted to be favored by selection during invasions due to the relative strength of genetic drift (Bock et al, 2015; Dlugosch, Anderson, et al, 2015), particularly when gene flow is involved (Reatini & Vision, 2020). Inversions are increasingly being identified by genomic studies as playing important roles in adaptation (Huang and Rieseberg, 2020) and have recently been shown to contribute to the success of a plant invasion (Battlay et al, 2022).…”

Genetic architecture influences when and how hybridization contributes to colonization

“…Analyses of variance (ANOVAs) were then performed to test the effect of the different factors and their interactions on lag time duration. Data and code for reproducing the analyses are available from Dryad (Reatini and Vision 2020).…”

Reconstructing the history and biological consequences of a plant invasion on the Galápagos islands

“…Several factors could be involved in this success. Despite intense bottlenecks, diversity could be maintained by other means, including multiple independent introductions (Facon et al, 2008;Kolbe et al, 2004) or via hybridization with congenerics present in the new habitat (Ellstrand & Schierenbeck, 2000;Lavergne & Molofsky, 2007;Reatini and Vision, 2020;Stepien et al, 2005). Of these mechanisms, hybridization might be particularly important for facilitating invasion into island habitats.…”