The genetic legacy of Mother Goose– phylogeographic patterns of lesser snow goose Chen caerulescens caerulescens maternal lineages

Abstract

By using the polymerase chain reaction to amplify and sequence 178 bp of a rapidly evolving region of the mtDNA genome (segment I of the control region) from 81 individuals, approximately 11% of the variation present in the lesser snow goose Chen caerulescens caerulescens L. mitochondrial genome was surveyed. The 26 types of mtDNA detected formed two distinct mitochondrial clades that differ by an average of 6.7% and are distributed across the species range. Restriction analysis of amplified fragments was then used to assign the mtDNA of an additional 29 individuals to either of these clades. Within one major clade, sequence among mtDNAs was concordant with geographic location. Within the other major clade the degree of sequence divergence among haplotypes was lower and no consistent geographic structuring was evident. The two major clades presumably result from vicariant separation of lesser snow geese during the Pleistocene.

Population structure and loss of genetic diversity in the endangered white-headed duck, Oxyura leucocephala

“…Although selection due to varying environmental conditions could produce ecologically relevant differences that are not reflected in neutral genetic markers, slight morphological differences might also reflect purely phenotypic responses to varying environments. While the power of our analyses to detect small differences in haplotype frequencies was limited by small sample size, we can conclude that all whiteheaded duck populations share recent common ancestry and show no evidence of the relatively deep historical divisions that molecular data have revealed in some other waterfowl species (Avise et al 1990;Quinn 1992;McCracken et al 2001;Paxinos et al 2002;McCracken and Sorenson 2005), nor any evidence of significant structuring of mitochondrial variation produced by strong female philopatry (Scribner et al 2001;Tiedemann et al 2004). Lack of genetic structure coupled with recent expansion, apparently following the retreat of ice sheets after the last glacial maximum, has been observed in other avian species (Mila´et al 2000;Zink et al 2002), including eiders (Pearce et al 2004).…”

“…Our analyses provide evidence for population expansion as seen from the haplotype network (Figure 2) Given the absence of fossil evidence and the fact that our data from historical samples comprise a short segment of the highly variable control region, it is difficult to establish a molecular clock. Portions of the control region evolve up to ten times as fast as the rest of the mtDNA in some waterfowl (Quinn 1992), so the small number of mutations separating white-headed duck haplotypes might have accumulated in the last few thousand years. Expansion from a single refugium following the most recent retreat of glaciers from Europe c. 10,000 years ago (Birks and Ammann 2000) seems consistent with the data.…”

Cryptic genetic variation and paraphyly in ravens

“…If the two common raven clades are randomly interbreeding and genes are intermixing completely across large areas of the western US, then this may be a striking example of geographical isolation and molecular di¡eren-tiation, followed by subsequent remixing of the two gene pools (also see Fleischer & Rothstein 1988;Quinn 1992;Shapiro 1998). The geographical distribution and phylogenetic patterns of ravens make them an excellent group for studying the process of speciation, or possibly the processes that allow separate populations to merge and not di¡erentiate as species.…”

“…Omland et al 1999;Voelker 1999); (ii) remixing of two or more distinct genetic groups (e.g. Quinn 1992); or (iii) retention of genetic polymorphism within a phenotypically uniform species (Neigel & Avise 1986;Avise 1994). Discrete genetic breaks within species can provide unique insights into species and population histories, and are an important focus of phylogeographic studies (e.g.…”

Low Genetic Variation in the Heath Hen Prior to Extinction and Implications for the Conservation of Prairie-Chicken Populations

“…Group extractions (n=16) were conducted with blank controls and all controls were negative when subjected to PCR. Two primer pairs, 521H (Quinn and Wilson 1993)/ 186L (5¢-CCTTATCCACATTTCTCCCAA-3¢) and 272H (5¢-TATGTCTATCGAGCATTCAT-3¢)/16 775L (Quinn 1992) were used to sequence a total of 394 basepairs (bp) from the 5¢ region of the mitochondrial DNA control region. PCR was conducted following described methods (Johnson et al , 2004) with the addition of 1.0 M Betaine to the reaction to improve PCR efficiency.…”