Mitochondrial DNA and plumage evolution in the white wagtail Motacilla alba

336.We analyzed sequences of two mitochondrial DNA (mtDNA) gene regions (controlregion and ND2) totaling 1477 base-pairs from 232 specimens of the white wagtailMotacilla alba obtained from 27 localities throughout Eurasia. Although overallhaplotype diversity was relatively low (0.79) and the most common haplotype wasshared by 45% of individuals, belonging to six subspecies, a high level of populationdifferentiation was detected. The mtDNA tree revealed three clades: (1) mostindividuals from Krasnodar (belonging to M. a. alba subspecies), (2) all individualsfrom Almaty and some from Primor’e (belonging to M. a. personata, M. a. lugens andM. a. leucopsis subspecies), and (3) the remaining individuals (representing allsubspecies and all localities except Almaty). We suggest that these three cladesrepresent historically isolated populations that relatively recently came into secondarycontact in Krasnodar and Primor’e. None of the six subspecies were reciprocallymonophyletic in the mtDNA tree. The Krasnodar population appeared to receiveimmigrants from other localities, but distinctive haplotypes from this locality did notappear elsewhere, suggesting asymmetric gene flow. Signatures of recent gene flowbetween northern populations were detected, and there was no evidence of isolation bydistance within the northern group of populations. Mismatch distributions for mostlocalities were consistent with population expansions. We also analyzed 12 maleplumage characters from 93 study skins sampled from 24 populations. Phylogenetictrees resulting from separate genetic and morphological analyses were incongruent.Plumage evolution seems to be under strong sexual or natural selection, which favorsparticular phenotypes in various areas irrespective of the mitochondrial background.Dispersal events at different evolutionary times could have obscured the effectsof earlier isolation events. The mtDNA data does not support species status forM. a. lugens and M. a. personata, which shared haplotypes with other subspecies ofM. alba. We recommend that M. lugens and M. personata are placed as juniorsynonyms of M. alba.A. Pavlova and R. M. Zink (correspondence), Bell Museum of Natural History,University of Minnesota, St. Paul, MN 55108, E-mail: rzink@biosci.umn.edu. S. Rohwer,Burke Museum and Department of Zoology, University of Washington, Seattle,Washington 98195-3010. E. A. Koblik and Y. A. Red’kin, Moscow State University,Zoological Museum, Moscow, Bol’shaya Nikitskaya 6, Russia. I. V. Fadeev and E. V.Nesterov, State Darwin Museum, 57 Vavilova street, Moscow 117292, Russia.