Francioli Yannick / Biology / Faculty Mentor: Todd Castoe
A fundamental goal of biology is to understand the mechanisms that promote reproductive isolation and drive the generation and maintenance of species. Theory predicts that progress towards speciation involves the aggregate effects of direct and indirect selection across a multitude of loci that collectively produce a strong genome-wide barrier1. Genomic coupling is the result of the interaction of selection to keep conspecific alleles together and recombination, which inherently disrupt linkage2. Through coupling, genome-wide genetic associations are predicted to be the underlying mechanism by which reproductive isolation builds up within and across chromosomes and can eventually lead to genome congealing and completely prevent any gene flow between species2. Here, we leveraged a rattlesnake hybrid zone and developed and approach to assess genome-wide coupling and investigate the synergistic interactions of intra- and interchromosomal linkage disequilibrium. We show evidence of a complex multi-locus barrier strengthened by coupling, involving incompatibilities related to venom resistance, which illustrate the mechanism by which coupling is predicted to lead to speciation.
Leave a Reply