Novel trophic niches drive variable progress towards ecological speciation within an adaptive radiation of pupfishes.

摘要: Adaptive radiation is recognized by a rapid burst of phenotypic, ecological and species diversification. However, it unknown whether different within an adaptive evolve reproductive isolation at rates. We compared patterns genetic differentiation between nascent Cyprinodon pupfishes using genotyping sequencing. Similar to classic radiations, this clade exhibits morphological diversification rates two are novel trophic specialists, scale-eater hard-shelled prey specialist (durophage), yet the <10 000 years old. Both specialists abundant generalist all coexist in benthic zone lakes on San Salvador Island, Bahamas. Based 13 912 single-nucleotide polymorphisms (SNPs), we found consistent differences each across seven lakes. The showed greatest clustered lakes, whereas durophage populations often with sympatric populations, parallel speciation strong evidence admixture supporting single origin genome-wide introgression populations. conclude that further along speciation-with-gene-flow continuum than suggest landscapes underlying these niche environments drive variable progress towards same habitat. Our previous measurements fitness surfaces support conclusion: scale-eating peak may be more distant complex landscape driving radiation.