Low support for separate species within the redpoll complex (Carduelis flammea–hornemanni–cabaret) from analyses of mtDNA and microsatellite markers

Publication Type:Journal Article
Year of Publication:2008
Authors:Marthinsen, G, Wennerberg, iv, L, LIFJELD, JANT
Journal:Molecular Phylogenetics and Evolution
Volume:47
Date Published:2008
ISBN Number:1055-7903
Keywords:Acanthis, Acanthis flammea, AMOVA, Arctic redpoll, Bergmann’s rule, Carduelis, Carduelis flammea, Carduelis flavirostris, Common redpoll, ecological speciation, Fringillidae, gene flow, Gloger’s rule, Greater redpoll, Lesser redpoll, Linaria, Linaria flavirostris, Mealy redpoll, Principal coordinate analysis, recent divergence, structure
Abstract:The redpoll complex, consisting of three currently recognized species (Carduelis flammea, C. hornemanni and C. cabaret), is polytypic in biometry, morphology, physiology and behaviour. However, previous genetic work has not revealed any indications of genetic differentiation. We analysed sequence variation in the mtDNA control region, and allele frequencies of supposedly faster evolving microsatellites (n = 10), in an attempt to detect molecular genetic support for the three species, as well as two subspecies of C. flammea (ssp. flammea and rostrata), within this complex. We used samples from two subspecies of the twite (Carduelis flavirostris, ssp. flavirostris and rufostrigata) as outgroup. We found no structure among redpoll individuals in mtDNA haplotypes or microsatellite allele frequencies, and only marginal differences between redpoll taxa in analyses of molecular variance (AMOVAs) of predefined groups. In contrast, the two twite subspecies constituted two well-supported monophyletic groups. Our study thus strengthens previous indications of low genetic support for current redpoll taxa. Two major alternative interpretations exist. Either redpolls form a single gene pool with geographical polymorphisms possibly explained by Bergmann’s and Gloger’s rules, or there are separate gene pools of recent origin but with too little time elapsed for genetic differentiation to have evolved in the investigated markers. Future studies should therefore examine whether reproductive isolation mechanisms and barriers to gene flow exist in areas with sympatric breeding.
URL:http://www.sciencedirect.com/science/article/pii/S1055790308000961
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