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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

Vliv individuálních vlastností samic čejky chocholaté (Vanellus vanellus) na kvalitu snůšky, párovací status a inkubační úsilí samce / The role of individual traits in the Northern Lapwing (Vanellus vanellus) females on breeding performance, mating status and male incubation effort

Sládeček, Martin January 2015 (has links)
Feather ornaments and its role as a signals in sexual selection has been broadly studied topic in avian biology. However, vast majority of studies focus especially on role of male ornamentation and female preferences in sexual selection. Despite this fact, recent work shows, that similar palette of adaptive functions can be found for female feather ornaments, and male preferences for them, respectively. This study focuses on possible importance of female melanin-based ornaments and other individual on breeding performance in the Northern Lapwing (Vanellus vanellus), common polygynous wader breeding in agricultural landscape. No significant predictor of female investment to egg size was found. Long winged females with bigger proportion of secondaries changed during prenuptial moulting and bigger extent of melanin ornaments tended, surprisingly, to later timing of breeding. Contrary to this trend, extent of female ornamentation seems to be sexually selected trait by males. Analysis of male incubation behavior shows, that males incubate more in nests of more ornamented females, as well as in nests in later incubation stage. These findings seems to be in a good agreement with "Differential allocation hypothesis". On the other site, no effect of clutch egg sizes and timing of breeding was found....
2

An Investigation of the Communal Breeding System of the Smooth-billed Ani (Crotophaga ani).

Blanchard, Leanne 09 1900 (has links)
In social systems, the distribution of reproduction among group members is termed reproductive skew. This study was intended to address the issues of reproductive skew within the communally breeding smooth-billed ani employing genetic data to complement behavioural data. The aims of the study were: 1) to develop smooth-billed ani specific DNA markers to be used in the assessment of parentage 2) to determine parentage of buried eggs and surviving offspring to assess whether a reproductive skew pattern is seen 3) to comment on adult relatedness within smooth-billed ani groups. Smooth-billed ani microsatellite DNA sequences were isolated and characterized for use in a parentage/kinship analysis. Lambda Zap Express was used to construct a library of recombinant phage which was screened with TG and AAT probes. Five loci were characterized with between 4 and 9 alleles with heterozygosity values ranging from 0.538 to 0.840. The combined total exclusionary power of the five loci was 0.8869. Offspring loss due to egg destruction in the form of burial has been observed in smooth-billed anis. The issue of reproductive skew as a result of egg burial was addressed by estimating parentage of offspring both buried and remaining in the incubated clutch using 5 species specific microsatellite DNA markers. Evidence for an egalitarian system exhibiting very low skew was found. The significant factors affecting the potential for bias were laying order, laying timing and the number of breeding females. The relatedness of members within a social group may affect the amount of reproductive skew observed. Adults within nesting groups were tested for evidence of relatedness using the pedigree analysis program KINSHIP. Ten percent of dyads showed significant relationships. Low incidence of relatedness provided evidence that smooth-billed ani groups do not contain a large number ofyoung remaining at the natal nest nor was there evidence that regular dispersing within sibling units occurs. There was some evidence that a young male remained on his natal territory while a young female dispersed to a neighbouring territory. Low relatedness between adults and very low reproductive skew were consistent with the prediction of an egalitarian system / Thesis / Master of Science (MS)
3

Genetic Disequilibria and the Interpretation of Population Genetic Structure in Daphnia

Berg, Lars M. January 2001 (has links)
Understanding the processes that shape the spatial distribution of genetic variation within species is central to the evolutionary study of diversification and demography. Neutral genetic variation reflects past demographic events as well as current demographic characteristics of populations, and the correct interpretation of genetic data requires that the relative impact of these forces can be identified. Details of breeding systems can affect the genetic structure through effects on effective migration rate or on effective population size. Restrictions in recombination rate lead to associations between neutral marker genes and genes under natural selection. Although the effects on genetic structure can be substantial, the process will often be difficult to tell apart from stochastic effects of history or genetic drift, which may suggest erroneous conclusions about demography. In cyclically parthenogenetic freshwater invertebrates, which alternate between sexual and asexual reproduction, demographic fluctuations and reliance on diapausing eggs for dispersal enhances neutral genetic differentiation as well as effects of selection on associated genes. Although genetic founder effects are expected to be profound and long-lasting in these species, genetic hitch-hiking may reduce initial strong differentiation rapidly if better adapted genes are introduced by mutation or immigration. Fluctuating environmental conditions have been suggested to generate rapid shifts in the frequencies of clones during the asexual phase. In the presence of egg banks resting in sediments, genetic diversity is stabilised and the importance of migration for differentiation is reduced. Studies of unstable and young populations of cyclically parthenogenetic Daphnia pulex showed substantial variation for important fitness traits, within as well as between populations, despite hypothesised recent founder effects. Neutral markers indicated genetic equilibrium, but changes in clonal composition during asexuality disrupted the genetic structure in a manner compatible with local adaptation and exclusion of immigrants. This illustrates that the forces affecting sexual progeny may be markedly different from those shaping the structure among asexual individuals.
4

Relações entre estrutura sócio-espacial e fluxos gênicos em uma população de mouflons mediterrâneos (Ovis gmelini)

Netto, Newton Tércio [UNESP] 23 May 2011 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:32:16Z (GMT). No. of bitstreams: 0 Previous issue date: 2011-05-23Bitstream added on 2014-06-13T19:21:46Z : No. of bitstreams: 1 tercionetto_n_dr_jabo.pdf: 2777355 bytes, checksum: f61f3dfa0040cb7d42df00390237a91a (MD5) / Estudos recentes revelaram a estruturação de diversas populações de vertebrados a um nível local. Essa estruturação tem sido relacionada aos sistemas de acasalamento e padrões de filopatria-dispersão das espécies. Esse estudo objetivou estudar como a organização espacial contribui para a estruturação genética de uma população. Avaliamos os papéis da filopatria e da dispersão a partir do comportamento espacial e da estrutura genética de uma população de mouflons mediterrâneos. Localizações obtidas por radiotelemetria foram utilizadas para descrever o comportamento espacial de ambos os sexos durante o período reprodutivo. Fêmeas mostraram-se filopátricas e revelaram uma estruturação sócio-espacial em unidades de população. Parte dos machos manteve-se fiel ao domínio reprodutivo de um ano a outro, enquanto outros dispersaram para outro domínio. Domínios reprodutivos de machos não sobrepõem apenas uma unidade de fêmeas. Inferimos sobre os fluxos gênicos promovidos pelos machos que se deslocam entre as unidades, a partir do polimorfismo de microsatélites. O teste de Hardy-Weinberg sugeriu uma população em desequilíbrio. Os testes de diferenciação gênica e genotípica e o FST confirmaram a estruturação genética da população. Mas não houve perda de heterozigose a nível da população ou no interior das unidades. O comportamento individual dos animais aparece como um fator importante da estruturação genética da população. Fêmeas mostram-se fortemente filopátricas e a aleatoriedade dos acasalamentos parece assegurada por um sistema reprodutivo baseado na promiscuidade. O fluxo gênico é mantido pela dispersão de parte dos machos, mantendo a panmixia no interior das unidades / Recent studies revealed the presence of fine-scale genetic structure in wild vertebrate populations. This structure has been related to breeding systems and specie’s philopatry-dispersal pattern. The objective of this study was to examine how the spatial organization contributes to the genetic structure of a population. The role of philopatry and dispersion was evaluated from the spatial behaviour and genetic structure of a mouflon sheep population. Radio-tracking data was used to describe spatial behavior for both sexes during rut. Ewes were found to be partitioned in sociospatial units o which they were faithful. Movements patterns of rams were much more variable: some males remain faithful to the breeding area from one year to another, while others dispersed to other domain. Male rutting range can overlap more than once unit. We can infer about the male gene flow promoted by moving between the units from the polymorphism of microsatellites. Hardy-Weinberg test suggested disequilibrium in population. Genic and genotypic differentiation tests and FST confirmed the genetic structure of population. But there was no loss of heterozigosys neither at the population level nor within the units. The individual behavior of animals appears an important factor of population genetic structuring. Females are strongly phylopatrics. Randomness of matings would be assured by a reproductive system based on promiscuity. The gene flow between units and panmixia inside the units are maintained by some dispersal males
5

Chov ovcí v podmínkách ekologického a konvenčního systému hospodaření / Sheep breeding in conditions organic and conventional farming

HOMOLKOVÁ, Monika January 2013 (has links)
Sheep husbandry has been rising for a long time in the Czech Republic. The number of flocks of sheep has been increasing gradually, which is an evidence of their popularity among breeders. Thanks to the hardiness of sheep, their breeding is mostly concentrated in the mountaneous an submontaneous areas where they are utilized not only for prime meat or milk production but also for mainaining the landscape. The goal of my thesis is to evaluate sheep husbandry at two farms managed under conventional and ecological conditions respectively, in the submontaneous area of Southern Bohemia. The distance between the two farms is approximately 1.5 km. The same indicators ( ewe reproduction, flock management, nutrition, pasture methods and system of breeding) were examined at both farms. The data were observed during the period of two years ? 2011 and 1012.
6

Caracterização bioeconômica de diferentes idades de acasalamento de gado de corte no sudoeste da Bahia e no noroeste do Paraná / Bioeconomics characterization of different ages mating of beef cattle in the southwest of Bahia and in the northwest of Parana

Batista, Perecles Brito 26 June 2009 (has links)
Made available in DSpace on 2017-07-10T17:48:18Z (GMT). No. of bitstreams: 1 Perecles_Brito_Batista.pdf: 363574 bytes, checksum: f44fc77e2f19c4a5cd4f3fed1a536840 (MD5) Previous issue date: 2009-06-26 / Fundação Araucária / Aiming to characterize the economic viability of different ages of mating of beef cattle in the southwestern regions of Bahia and northwestern Paraná, a simulation was performed by the software NTIA / CM (1995) of EMBRAPA and Excel spreadsheet of three systems creates beef cattle with different levels of fertility. System 1, the age at first coverage was 26 months; System 2, the age at first coverage was 18 months for heifers and 26 months earlier for heifers that fail to cover first, System 3, age was the first cover 15 months. In all three systems the production costs were higher in the state of Paraná. The systems 1 and 2 were economically unviable due to low fertility and high mortality rates established in the two states. The rate of sale of animals such systems was considered high and the herd has not achieved stability in the number of heads during the course of 10 years. In system 1, birth rates of 82 and 60%, 83 and 60% for cows and heifers in the two states respectively and 77.5 and 75%, 78.5 and 75% in the 2 for the same categories in both states showed that it is possible that the herd reach the numerical stability, but the producer would have their profitability undermined by the high mortality rate in this system. The system creates 3, was more profitable because the best rates applied. The age of the first 15 months cover attaches to the system creates a fast return on invested capital that systems that require pregnancies of females over 24 months. The system 3 in Bahia had rates of return on investment equal to those obtained with applications in CBD and rdb files and 4.46% lower than the investment in savings. In Paraná the rate of return was lower than alternative investments cited. The best value was achieved in the economic system 3 in both states because better and enjoy better levels of productivity / Com o objetivo de caracterizar a viabilidade econômica de diferentes idades de acasalamento de gado de corte nas regiões sudoeste da Bahia e noroeste do Paraná, foi realizada uma simulação através do software o NTIA/CM (1995) da EMBRAPA e planilha Excel de três sistemas de cria de bovinos de corte com diferentes índices de fertilidade. Sistema 1, a idade à primeira cobertura foi de 26 meses; Sistema 2, a idade à primeira cobertura foi de 18 meses para novilhas precoces e 26 meses para as novilhas que falharem à primeira cobertura; Sistema 3, a idade a primeira cobertura foi de 15 meses. Nos três sistemas os custos de produção foram maiores no estado do Paraná. Os sistemas 1 e 2 foram inviáveis economicamente devido aos baixos índices de fertilidade e altos índices de mortalidade estabelecidos nos dois estados. A taxa de venda de animais destes sistemas foi considerada alta e o rebanho não alcançou a estabilidade em número de cabeças no período de evolução de 10 anos. No sistema 1, taxas de natalidade de 82% e 60%, 83% e 60%, para vacas e novilhas, respectivamente nos dois estados e, de 77,5% e 75%, 78,5% e 75% no sistema 2 para as mesmas categorias nos dois estados mostraram que é possível que o rebanho alcance a estabilidade numérica, porém, o produtor teria sua rentabilidade comprometida pela alta taxa de mortalidade neste sistema. O sistema 3 de cria se mostrou mais rentável devido os melhores índices aplicados. A idade de 15 meses a primeira cobertura atribui ao sistema de cria um retorno mais rápido do capital investido que sistemas que preconizam prenhezes de fêmeas acima dos 24 meses. O sistema 3 na Bahia apresentou taxas de retorno do investimento iguais aos obtidos com aplicações financeiras em CDB e RDB e 4,46% menor que o investimento em poupança. No Paraná a taxa de retornou foi inferior aos investimentos alternativos citados. A melhor rentabilidade econômica foi alcançada no Sistema 3 em ambos os Estados devido um melhor desfrute e índices de produtividade mais adequados
7

Sexual conflict over parental care in penduline tits

van Dijk, Rene E. January 2009 (has links)
Sexual conflict, the different interests of males and females over reproduction, is a potent evolutionary force. Here I investigate sexual conflict in the context of parental care by focussing on two questions: (i) which behavioural, morphological and environmental traits influence the parents’ decision to care for the brood or desert? (ii) How does sexual conflict influence the evolution of behaviour and morphology? I investigate both questions using a small, polygamous passerine bird, the Eurasian penduline tit Remiz pendulinus, which exhibits intense sexual conflict over parental care such that either the male, the female or both parents desert the clutch. Using detailed behavioural observations during the crucial few days preceding desertion, I argue that it may be in the parents’ best interest to conceal their intention to care for (or desert) their brood. The rapid resulting process that leads to variable parental care resembles a coordination game in which either parent may desert first. I developed a game-theoretical model that suggests that a key to resolving the conflict between parents is the sex difference in reproductive payoffs for given parental care strategies, rather than differences in parental quality per se. Environmental variables (e.g. food availability and mating opportunities) seem only subsidiary in the decision-making process of parents. My final chapter explores ramifications of sexual conflict at an evolutionary timescale. By comparing the highly polygamous Eurasian penduline tit with the monogamous Cape penduline tit, I show that morphological and behavioural differences between these two species are consistent with predictions of sexual conflict theory. During my PhD I also identified that there is considerable variation in breeding systems within different species of penduline tits. I argue that by studying these systems new insights will emerge into (i) the drivers of breeding systems, and (ii) neural and genomic traits that underlie breeding system evolution.
8

Diverse interactions of heterotrophic plants with their hosts, pollinators and seed dispersers / 従属栄養植物が宿主や送粉者、種子散布者と織りなす多様な相互作用

Suetsugu, Kenji 24 September 2014 (has links)
京都大学 / 0048 / 新制・課程博士 / 博士(人間・環境学) / 甲第18605号 / 人博第701号 / 新制||人||167(附属図書館) / 26||人博||701(吉田南総合図書館) / 31505 / 京都大学大学院人間・環境学研究科相関環境学専攻 / (主査)教授 加藤 眞, 教授 市岡 孝朗, 教授 瀬戸口 浩彰, 教授 宮本 嘉久, 教授 新宮 一成 / 学位規則第4条第1項該当 / Doctor of Human and Environmental Studies / Kyoto University / DGAM
9

Microsatellite DNA Analysis of the Communal Breeding System of the Smooth-billed Ani (Crotophaga ani) in Southwest Puerto Rico

Startek, Jennifer Melissa 05 1900 (has links)
The communal breeding system of the smooth-billed ani (Crotophaga ani) was studied at two wildlife refuges in southwest Puerto Rico. Groups ranged in size from 2 to 9 adults, and communal clutches ranged in size from 11 to more than 25 eggs. Microsatellite DNA loci were isolated and used to examine the mating system and the extent of reproductive skew in individual groups. Loci were also screened in guira cuckoos (Guira guira) to examine the relationships suggested by Quinn et al. (1994). In the four focal smooth-billed ani groups, I found suggestions of monogamy, polygamy, and incidents of intraspecific brood parasitism. In all groups, incubated clutch size and microsatellite data indicate that subordinate females are gaining some reproductive success. At one nest, evidence suggested a decrease in the intensity of reproductive skew between successive nests. Although the data are limited, they suggest that alternative strategies to monogamy may be more prevalent than previously believed, and that reproductive skew may be affected by the availability of limiting resources within the breeding season. / Thesis / Master of Science (MS)
10

Genetic Disequilibria and the Interpretation of Population Genetic Structure in <i>Daphnia</i>

Berg, Lars M. January 2001 (has links)
<p>Understanding the processes that shape the spatial distribution of genetic variation within species is central to the evolutionary study of diversification and demography. Neutral genetic variation reflects past demographic events as well as current demographic characteristics of populations, and the correct interpretation of genetic data requires that the relative impact of these forces can be identified. Details of breeding systems can affect the genetic structure through effects on effective migration rate or on effective population size. Restrictions in recombination rate lead to associations between neutral marker genes and genes under natural selection. Although the effects on genetic structure can be substantial, the process will often be difficult to tell apart from stochastic effects of history or genetic drift, which may suggest erroneous conclusions about demography.</p><p>In cyclically parthenogenetic freshwater invertebrates, which alternate between sexual and asexual reproduction, demographic fluctuations and reliance on diapausing eggs for dispersal enhances neutral genetic differentiation as well as effects of selection on associated genes. Although genetic founder effects are expected to be profound and long-lasting in these species, genetic hitch-hiking may reduce initial strong differentiation rapidly if better adapted genes are introduced by mutation or immigration. Fluctuating environmental conditions have been suggested to generate rapid shifts in the frequencies of clones during the asexual phase. In the presence of egg banks resting in sediments, genetic diversity is stabilised and the importance of migration for differentiation is reduced.</p><p>Studies of unstable and young populations of cyclically parthenogenetic <i>Daphnia pulex</i> showed substantial variation for important fitness traits, within as well as between populations, despite hypothesised recent founder effects. Neutral markers indicated genetic equilibrium, but changes in clonal composition during asexuality disrupted the genetic structure in a manner compatible with local adaptation and exclusion of immigrants. This illustrates that the forces affecting sexual progeny may be markedly different from those shaping the structure among asexual individuals.</p>

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