Stick Insect Genomes Reveal Natural Selection’s Role in Parallel Speciation
This week we will read a recent paper by Patrik Nosil and colleagues on the repeatability of the genetic changes driving the divergence of populations into new species. The paper is entitled "Stick Insect Genomes Reveal Natural Selection’s Role in Parallel Speciation" and was recently published in Science. The reported findings indicate that natural selection can drive parallel phenotypic evolution via parallel genetic changes.
Stick Insect Genomes Reveal Natural Selection’s Role in Parallel Speciation (Soria-Carrasco, Gompert et al. 2014, Science)
Natural selection can drive the repeated evolution of reproductive isolation, but the genomic basis of parallel speciation remains poorly understood. We analyzed whole-genome divergence between replicate pairs of stick insect populations that are adapted to different host plants and undergoing parallel speciation. We found thousands of modest-sized genomic regions of accentuated divergence between populations, most of which are unique to individual population pairs. We also detected parallel genomic divergence across population pairs involving an excess of coding genes with specific molecular functions. Regions of parallel genomic divergence in nature exhibited exceptional allele frequency changes between hosts in a field transplant experiment. The results advance understanding of biological diversification by providing convergent observational and experimental evidence for selection’s role in driving repeatable genomic divergence.