Genetic and phenotypic divergence within and between cinnamon teal (Anas cyanoptera) and blue-winged teal (A. discors)

Thesis (Ph.D.) University of Alaska Fairbanks, 2011Spatial heterogeneity in selection pressures can lead to extensive morphological variation and differences at functional genes between populations across a species' range without corresponding genetic variation at neutral loci. Divergent selection among populations may thus lead to intraspecific variation and in many cases speciation. Phenotypic and genetic structure within and between Cinnamon Teal (Anas cyanoptera) and the closely related Blue-winged Teal (A. discors) was assessed using body size measurements and neutral genetic markers in conjunction with a functional locus, hemoglobin. Cinnamon Teal are composed of five subspecies corresponding to distinct ecogeographic regions in North and South America. Subspecies and geographic regions differed significantly in overall body size, with the largest subspecies and the largest individuals found at high elevations in the central Andes (A. c. orinomus) and at high latitudes in southern Patagonia (A. c. cyanoptera). South American populations showed strong positive correlations with latitude and elevation while the migratory subspecies in North America (A. c. septentrionalium) showed few significant correlations with elevation and no relationship between latitude and body size. In addition, plumage differences were restricted to between North and South America as there was extensive variation observed within continents. Cinnamon Teal highland and lowland populations showed strong divergence in body size (Pst=0.56) and exhibited frequency differences in one non synonymous [alpha]-globin amino acid polymorphism (Asn/Ser-[alpha]9; Fst = 0.60), despite considerable admixture of reference loci. Selection pressures imposed by the hypoxic highland environment have likely resulted in asymmetric gene flow from the highlands into the lowlands following a highland colonization event from the lowlands. Cinnamon Teal and Blue-winged Teal show distinct but paraphyletic mitochondria) DNA ... and broadly shared nuclear alleles. Unlike South American Cinnamon Teal, North American Cinnamon Teal and Blue-winged Teal are characterized by high genetic diversity, large effective population size, and recent population expansion. Haplotypic and allelic sharing across continents is likely because of incomplete lineage sorting rather than ongoing gene flow. Within-continent estimates yielded higher migration rates consistent with hybridization. However, Cinnamon Teal and Blue-winged Teal are similar in body size; differences in plumage coloration may reduce hybridization events.Introduction -- 1. Ecogeographic variation in cinnamon teal (Anas cyanoptera) along elevational and latitudinal gradients -- 2. Genetic and phenotypic divergence between high- and low-elevation populations of two recently diverged cinnamon teal subspecies -- 3. Speciation, subspecies divegence, and paraphyly in cinnamon teal and blue-winged teal -- 4. Plumage and body size differentiation in blue-winged teal and cinnamon teal -- 5. Color divergence among cinnamon teal (Anas cyanoptera) subspecies from North America and South America -- 6. Specimen shrinkage in cinnamon teal

The Dictionary of Modern Proverbs: Third Supplement

This is the third supplement to The Dictionary of Modern Proverbs (New Haven, Connecticut: Yale University Press, 2012), edited by Charles Clay Doyle, Wolfgang Mieder, and Fred R. Shapiro. It registers 53 additional modern Anglo-American proverbs with historical dates and contextualized references. We intend to publish such supplements from time to time and hope eventually to bring out a new edition of our dictionary