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Plectrophenax (1 Viewer)

ntbirdman

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Winker K, Glenn TC, Faircloth BC. (2018) Ultraconserved elements (UCEs) illuminate the population genomics of a recent, high-latitude avian speciation event. PeerJ Preprints 6:e27035v1 https://doi.org/10.7287/peerj.preprints.27035v1

Abstract: Using a large, consistent set of loci shared by descent (orthologous) to study relationships among taxa would revolutionize among-lineage comparisons of divergence and speciation processes. Ultraconserved elements (UCEs), highly conserved regions of the genome, offer such genomic markers. The utility of UCEs for deep phylogenetics is clearly established and there are mature analytical frameworks available, but fewer studies apply UCEs to recent evolutionary events, creating a need for additional example datasets and analytical approaches. We used UCEs to study population genomics in snow and McKay’s buntings (Plectrophenax nivalis and P. hyperboreus). Prior work suggested divergence of these sister species during the last glacial maximum (~18-74 Kya). With a sequencing depth of ~30× from four individuals of each species, we used a series of analysis tools to genotype both alleles, obtaining a complete dataset of 2,635 variable loci (~3.6 single nucleotide polymorphisms [SNPs]/locus) and 796 invariable loci. We found no fixed allelic differences between the lineages, and few loci had large allele frequency differences. Nevertheless, individuals were 100% diagnosable to species, and the two taxa were different genetically (FST = 0.034; P = 0.03). The demographic model best fitting the data was one of divergence with gene flow. Estimates of demographic parameters differed from published mtDNA research, with UCE data suggesting lower effective population sizes (~92,500 - 240,500 individuals), a deeper divergence time (~241,000 yrs), and lower gene flow (2.8-5.2 individuals per generation). Our methods provide a framework for future population studies using UCEs, and our results provide additional evidence that UCEs are useful for answering questions at shallow evolutionary depths.

Link: https://peerj.com/preprints/27035/
 
Winker K, Glenn TC, Faircloth BC. (2018) Ultraconserved elements (UCEs) illuminate the population genomics of a recent, high-latitude avian speciation event. PeerJ Preprints 6:e27035v1 https://doi.org/10.7287/peerj.preprints.27035v1

Link: https://peerj.com/preprints/27035/

Line 84-85 of the preprint (my emphasis):
Snow buntings breed throughout the rest of the high-latitude Holarctic (our samples are from the southern edge of the Being sea on the Alaska Peninsula and an Aleutian island)
Nearest population to McKay's. So still no resolution of the question of monophyly of Snow with respect to McKay's . . .
 
Winthrow, Jack J. 2020. Plumage variation in Bering Sea Plectrophenax buntings and the specific status of McKay’s Bunting. Western Birds 51: 174-189.

Abstract:

McKay’s Bunting (Plectrophenax hyperboreus) is an enigmatic
and little studied passerine that breeds only on one of the most isolated groups of
islands in North America. Recent field work on those islands, St. Matthew and Hall,
and the nearby Pribilof Islands produced specimens of breeding McKay’s and Snow
Buntings (P. nivalis) demonstrating that plumage variation in both taxa is significant,
probably not related to age after the first year, and varies continuously between the
extremes within a taxon. The extreme of one closely approaches that of the other.
McKay’s Buntings are paler overall and levels of black pigmentation of the wings,
back, and tail, in conjunction with sex, allow qualitative diagnosability of these taxa
by plumage in nearly 100% of individuals if enough of the bird can be seen. Levels
of plumage variation are congruent with recent genomic work suggesting their relationship
is extremely close. Current information suggests that McKay’s Bunting is
not a biological species and should be considered a subspecies of the Snow Bunting.

[pdf]
 
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