title: Inferring the geographic mode of speciation by contrasting autosomal and sex-linked genetic diversity.
abstract: When geographic isolation drives speciation, concurrent termination of gene flow among genomic regions will occur immediately after the formation of the barrier between diverging populations. Alternatively, if speciation is driven by ecologically divergent selection, gene flow of selectively neutral genomic regions may go on between diverging populations until the completion of reproductive isolation. It may also lead to an unsynchronized termination of gene flow between genomic regions with different roles in the speciation process. Here, we developed a novel Approximate Bayesian Computation pipeline to infer the geographic mode of speciation by testing for a lack of postdivergence gene flow and a concurrent termination of gene flow in autosomal and sex-linked markers jointly. We applied this approach to infer the geographic mode of speciation for two allopatric highland rosefinches, the vinaceous rosefinch Carpodacus vinaceus and the Taiwan rosefinch C. formosanus from DNA polymorphisms of both autosomal and Z-linked loci. Our results suggest that the two rosefinch species diverged allopatrically approximately 0.5 Ma. Our approach allowed us further to infer that female effective population sizes are about five times larger than those of males, an estimate potentially useful when comparing the intensity of sexual selection across species.
authors: Department of Life Science, National Taiwan Normal University, Taipei, Taiwan.
authors: Jui-Hua
authors: JH
authors: Chu
authors: Daniel
authors: D
authors: Wegmann
authors: Chia-Fen
authors: CF
authors: Yeh
authors: Rong-Chien
authors: RC
authors: Lin
authors: Xiao-Jun
authors: XJ
authors: Yang
authors: Fu-Min
authors: FM
authors: Lei
authors: Cheng-Te
authors: CT
authors: Yao
authors: Fa-Sheng
authors: FS
authors: Zou
authors: Shou-Hsien
authors: SH
authors: Li
mesh_terms: D000818:Animals; D001499:Bayes Theorem; D019295:Computational Biology; D005260:Female; D046369:Finches / Q000145:classification* / Q000235:genetics*; D051456:Gene Flow; D056426:Genetic Loci; D049810:Genetic Speciation; D014644:Genetic Variation; D062305:Geographic Mapping; D008297:Male; D008957:Models, Genetic; D011110:Polymorphism, Genetic; D011156:Population Density; D012641:Selection, Genetic; D012730:Sex Chromosomes / Q000235:genetics*
keywords: Approximate Bayesian Computation; Carpodacus formosanus; Carpodacus vinaceus; allopatric speciation