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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Fine scale genetic structure and extra-pair parentage in the socially monogamous Upland Sandpiper

Casey, Ashley E. January 1900 (has links)
Master of Science / Department of Biology / Brett K. Sandercock / Samantha Wisely / In birds, the offspring of females in socially monogamous species can be sired not only by their social partner (within-pair mating) but also by other males (extra-pair mating), resulting in broods of mixed paternity. Several hypotheses have been proposed which attempt to explain the adaptive significance of this behavior, including the genetic diversity hypothesis, the good genes hypothesis, the genetic compatibility hypothesis and the fertility insurance hypothesis. I report results of a 5 year population study of the Upland Sandpiper (Bartramia longicauda) at Konza Prairie Biological Station in northeast Kansas. My objective was to determine the genetic mating system of this socially monogamous shorebird, and determine which of the genetic hypotheses best explains the patterns of extra-pair paternity (EPP) in the population. As part of the analysis, I optimized laboratory protocols for genetic sexing of our monomorphic study species. Potential errors in molecular sexing have been previously described but usually result in females being misidentified as males. Here, I report evidence that events in PCR reactions can lead to the opposite error, with males misidentified as females. I recommend the use of multiple primer sets and large samples of known-sex birds for validation when designing protocols for molecular sex analysis. I genotyped birds and tested for the existence of EPP in 58 family groups of Upland Sandpipers. I found 15% of chicks and 30% of broods were the result of extra-pair paternity in this population, which is high in comparison to other socially monogamous shorebirds. Only 2% of chicks and 2% of broods were attended by females unrelated to the young. I tested ecological covariates known to influence EPP in other birds including relatedness of mated pairs, morphology of the within-pair male, and nest initiation date, as well as variables which signify genetic benefits, including morphology of the offspring and offspring heterozygosity, but found no significant relationships. None of the prevailing genetic hypotheses can fully explain the high rates of EPP in this population of Upland Sandpipers. However, the discovery of fine-scale genetic structure in female birds, but not in males, suggests female natal philopatry or male-biased dispersal. This sex-specific genetic structure could be a mechanism of inbreeding avoidance, thereby eliminating the need for females to choose mates based on relatedness. This study provides the first estimates of EPP for the socially monogamous Upland Sandpiper, and provides evidence that the inbreeding avoidance mechanism of engaging in extra-pair copulations does not seem to be as important in Upland Sandpipers as in other socially monogamous shorebirds. Future research should include the identification of extra-pair males and the determination of offspring fitness after departure from the nest.
2

Revisão sistemática e filogeografia de Deconychura longicauda (Aves - Dendrocolaptidae)

BARBOSA, Ivã January 2010 (has links)
Submitted by Edisangela Bastos (edisangela@ufpa.br) on 2013-11-01T22:04:04Z No. of bitstreams: 2 license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) Dissertacao_RevisaoSistematicaFilogeografia.pdf: 1568206 bytes, checksum: e2ec5b83ef9574ae03b0e2d063b0b751 (MD5) / Approved for entry into archive by Ana Rosa Silva(arosa@ufpa.br) on 2013-11-14T15:31:19Z (GMT) No. of bitstreams: 2 license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) Dissertacao_RevisaoSistematicaFilogeografia.pdf: 1568206 bytes, checksum: e2ec5b83ef9574ae03b0e2d063b0b751 (MD5) / Made available in DSpace on 2013-11-14T15:31:19Z (GMT). No. of bitstreams: 2 license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) Dissertacao_RevisaoSistematicaFilogeografia.pdf: 1568206 bytes, checksum: e2ec5b83ef9574ae03b0e2d063b0b751 (MD5) Previous issue date: 2010 / Os limites interespecíficos da espécie politípica Deconychura longicauda (Dendrocolaptidae) foram investigados por uma análise conjunta, incluindo caracteres moleculares, morfológicos e vocais. Um total de 1.108 pares de bases de genes mitocondriais Cit b e ND2 foram usados para construir hipóteses filogenéticas, ao passo que os caracteres morfológicos e vocais foram analisados com métodos estatísticos univariado e multivariado. Todas as árvores filogenéticas recuperadas indicam altos níveis de diferenciação genética e estrutura filogeográfica em Deconychura longicauda, com o reconhecimento de quatro grupos principais bem apoiados, geograficamente constituídos por aves (1) do centro de endemismo Guiana no nordeste da América do Sul (2), da bacia amazônica excluindo o escudo das Guianas (3), do sopé oriental dos Andes, e (4), trans-Andinas da América do Sul e América Central. O nível de divergência genética entre estes clados varia de 6-8% (entre as aves Guianenses, não-Guianenses, do sopé dos Andes e trans-Andinas). Embora os caracteres morfológicos contribuam pouco para a diagnose em Deconychura, o canto, por outro lado, consistetemente os distinguem. Nós recomendamos com base, principalmente, em sua diagnose molecular e vocal o desdobramento de D. longicauda nas seguintes espécies filogenéticas e biológicas: Deconychura longicauda, D. pallida, D. zimmeri, D. connectens, D. typica e um táxon ainda não nomeado, endêmico do sopé oriental dos Andes. / The interspecific limits of the polytypic specie Deconychura longicauda (Dendrocolaptidae) were investigated by a combined analysis including molecular, morphological, and vocal characters. A total of 1,108 base pairs of mitochondrial genes Cyt b and ND2 were used to build phylogenetic hypotheses, whereas the morphological and vocal characters were analyzed with univariate and multivariate statistical methods. All recovered trees indicated high levels of genetic differentiation and phylogeographic structure in Deconychura longicauda, with the recognition of four major groups well-supported statistically and geographically consisting of birds from (1) the Guiana area of endemism in northeastern South America, (2) the Amazon basin excluding the Guianan shield, (3) the eastern slope of the Andes and (4) trans-Andean South America and Central America. The levels of genetic divergence between these clades reach 6-8% (among birds from Guianan, non-Guianan, eastern slope of the Andes and, trans-Andean birds). Although morphological characters contribute little to the diagnoses among Deconychura, loudsongs, consistently distinguish them. Based on those analyzes, we recommend the splitting of D. longicauda into the following phylogenetic and biological species based on their molecular and vocal unequivocal diagnoses: Deconychura longicauda, D. pallida, D. zimmeri, D. connectens, D. typica and one yet unnamed taxon endemic to the eastern slope of the Andes.

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