The work in this thesis deals with the ecology and evolution of adaptive individual variation. Ecologists have long used niche theory to describe the ecology of a species as a whole, treating conspecific individuals as ecological equivalent. During recent years, research about individual variation in diet and morphology has gained interest in adaptive radiations and ecological speciation. Such variation among individual niche use may have important conservation implications as well as ecological and evolutionary implications. However, up to date we know very little about the extension of this phenomenon in natural populations and the mechanisms behind it. The results in this thesis show that the extension of individual diet specialization is widely spread throughout the animal kingdom. The variation in diet is mainly correlated to morphological variation but not always. Furthermore, this variation in diet and morphology among individuals could be both genetically determined and environmentally induced and it mainly comes from trade-offs in foraging efficiency between different prey types. The results from a number of studies of perch also show that individual perch differ in morphology and diet depending on habitat, where littoral perch has a deeper body compared to pelagic perch. This difference in morphology corresponds to functional expectations and is related to foraging efficiency trade-offs between foraging in the littoral and pelagic zone of a lake. The variation in morphology in perch is mainly due to phenotypic plasticity but there are also small genetic differences between the littoral and pelagic perch. Two separate studies show that both predation and competition may be important mechanism for the variation in morphology and diet in perch. In conclusion, the results in this thesis show that individual variation in diet and habitat choice is a common phenomenon with lots of ecological and evolutionary implications. However, there are many mechanisms involved in this phenomenon on which we are just about to start learning more about, and only further research in this area will give us the full insight.

Made available in DSpace on 2015-04-20T12:31:07Z (GMT). No. of bitstreams: 1 Doriane Picanco Rodrigues.pdf: 621795 bytes, checksum: eef07284526ed1e322db593a7fb7fd98 (MD5) Previous issue date: 2006-09-28 / Fundação de Amparo à Pesquisa do Estado do Amazonas / The peach palm (Bactris gasipaes Kunth var. gasipaes) is a domesticated Neotropical palm that is important as a cultivated source of heart-of-palm. The genetic base for this agribusiness is the Pampa Hermosa landrace, Yurimaguas, Peru, that supplies the absolute majority of the seeds used in the expansion of the agribusiness and the improvement programs in Brazil, because its plants are spineless and more productive than those of other landraces. The use of molecular markers will permit better discrimination among populations and progenies of the landrace, guiding the selection of elite individuals and the search for hybrid vigor via maximization of heterozygosity within the landrace. This study evaluated the genetic diversity, population structure, and genetic relations among progenies and populations in a progeny trial maintained at INPA, Manaus, Amazonas, as well as the mating system of the peach palm using eight microsatellite loci, to support the improvement programs that use these genetic resources. Samples from three populations of the Pampa Hermosa landrace and from the market of Yurimaguas were collected from 12 progenies from the Cuiparillo River (n=140), 12 from the Paranapura River (n=130), nine from the Shanusi River (n=130), and 17 from the market at Yurimaguas (n=168). The sampling concentrated on plants (121) selected for heart length, and included non-selected plants (447). High genetic variability exists in the progeny trail, with a mean of 15.1 alleles per locus and total diversity (HT) equal to 0.82. The eight loci had 12 common alleles and 26 intermediate-frequency alleles found in all the populations and the market, and 83 alleles scattered among populations, with 14 private alleles. The observed heterozygosity (Ho) in the trail was less than the He in the majority of the loci; in locus Bg02-08 Ho was very inferior, suggesting a strong excess of homozygotes in this locus. The Ho was lowest in Shanusi (0.64) and highest in Paranapura (0.74). The inbreeding coefficient f varied among populations and market, and was highest in Shanusi (0.190) and lowest in Paranapura (0.111). Genetic divergence among the populations and the market was low (formula), certainly due to high gene flow (9.8 migrants per generation). The AMOVA detected 82.8% of the total variation within the progenies, 16% among the progenies within the populations and market, and only 1.3% among the populations and the market, describing a weak genetic structure and suggesting that the populations and the market are highly related. This relationship was confirmed by the dendrograms of the DAS genetic distances among the populations, with a greater proximity between the populations of Paranapura and Cuiparillo, and between the Mercado and Shanusi. The dendrogram of the DAS genetic distances showed high genetic affinity among the progenies and the formation of groups independent of their geographic origin. The Ho and He were high for the majority of the progenies, confirming high genetic variability within the progenies. The inbreeding coefficient (f) for the progeny trial was not different from zero, confirming an excess of heterozygotes and confirming the high variability observed from the estimates of heterozygosity. The analysis of the mating system found that the species is predominantly allogamous. The high out-crossing rate demonstrates that the progenies are derived almost exclusively from individuals experiencing out-crossing, probably due to the harvest representing the peak of the flowering season and to the synchronism of flowering associated with the behavior of the pollinator. The estimates of crossing among relatives (tm - ts) were significant (0.101 to 0.202), suggesting some biparental inbreeding, probably due to the farmers practice of planting open-pollinated seeds of only a few seed sources in the same plot. The estimate of paternity correlation was low (varying from 0.051 to 0.112), suggesting a small number of full sibs within the progenies and large number of pollen sources (9 to 20) participating in the crosses. The progenies of the trial are composed mainly of half sibs with great genetic variability, enhanced by the large number of pollen sources, and suggests that selection for heart-of-palm production could be based on the classic models of quantitative genetics applied to exclusively allogamous species. This information will be used to guide the crosses among progenies/populations. Two improvement plans are feasible with this information: population improvement, with crosses among highly divergent plants and progenies; by reciprocal recurrent selection, with the creation of divergent populations based on morphometric and genetic information. / A pupunheira cultivada (Bactris gasipaes Kunth var. gasipaes) é uma palmeira domesticada que vem se destacando como produtora de palmito. A base genética para o agronegócio vem da raça primitiva Pampa Hermosa, Yurimáguas, Peru, que fornece a maioria absoluta das sementes usadas na expansão do agronegócio e nos programas de melhoramento no Brasil, devido a possuir plantas sem espinho que são mais produtivas que as de outras raças. O uso de marcadores moleculares possibilitará discriminar com maior confiabilidade entre populações e progênies, orientando a seleção de matrizes e a busca de vigor híbrido via maximização de heterozigosidade dentro da raça. Este trabalho avaliou a diversidade e a estrutura genética, as relações genéticas entre as progênies e o sistema de reprodução de pupunheira da raça Pampa Hermosa, usando oito loci microsatélites, para apoiar os programas de melhoramento que usam estes recursos genéticos. Foram coletadas amostras de três populações de pupunheira da raça Pampa Hermosa e do mercado de Yurimáguas mantidas no ensaio de progênies do INPA, sendo 12 progênies do rio Cuiparillo (n=140), nove do rio Shanusi (n=130), 12 do rio Paranapura (n=130) e 17 do mercado de Yurimáguas (n=168). A amostragem concentrou-se em plantas selecionadas (121) para comprimento do palmito e não selecionadas (447). Existe alta variabilidade genética nas progênies do ensaio, com média de 15,1 alelos por loci e diversidade total (HT) igual a 0,82. Os oito loci apresentaram 12 alelos comuns e 26 alelos intermediários presentes em todas as populações e o mercado, e 83 alelos raros, sendo 14 privados, 10 esporádicos e 62 difundidos. As heterozigosidades observadas (Ho) no conjunto de plantas foram inferiores a heterozigosidade esperada (He) na maioria dos loci; no lócus Bg02-08 Ho foi muito inferior, sugerindo forte excesso de homozigotos neste lócus. A Ho foi menor em Shanusi (0,64) e maior em Paranapura (0,74). Os coeficientes de endogamia variaram entre populações e mercado, sendo maior em Shanusi (0,190) e menor em Paranapura (0,111). Detectou-se baixa divergência genética entre as populações e o mercado (fórmula), certamente devido ao alto fluxo gênico (9,8 migrantes por geração). A AMOVA detectou 82,8% do total da variação dentro das progênies, 16% entre as progênies dentro das populações e o mercado, e somente 1,3% entre as populações e o mercado, confirmando uma estrutura genética mínima e sugerindo que as populações e o mercado são altamente relacionadas. Este relacionamento foi confirmado pelos dendrogramas de distâncias (DAS) das populações, o qual mostra maior proximidade entre as populações de Paranapura e Cuiparillo, e entre o mercado e Shanusi. O dendrograma das progênies mostra alta afinidade genética e formação de grupos independentes de sua área geográfica de origem. As heterozigosidades observadas (Ho) e esperadas (He) foram altas para a maioria das progênies, evidenciando alta variabilidade genética dentro das progênies. O coeficiente de endogamia (f) para o conjunto de progênies não foi diferente de zero, evidenciando excesso de heterozigotos e confirmando a alta variabilidade observada pelas estimativas de heterozigosidade. A análise do sistema de reprodução revela que a espécie é predominantemente alógama. As altas taxas de cruzamento demonstram que as progênies são oriundas quase que exclusivamente por indivíduos provenientes de exocruzamento, provavelmente devido ao estágio fenológico (pico da safra) e ao sincronismo de floração associado ao comportamento do polinizador. Porém, as estimativas (tm - ts) foram significativas (0,101 a 0,202), evidenciando endogamia biparental, provavelmente decorrente da prática agrícola de plantar sementes de polinização aberta de poucas matrizes na mesma roça. A estimativa da correlação de paternidade foi baixa (variando de 0,051 a 0,112), indicando pequena proporção de irmãos-completos dentro das progênies e grande número de doadores de pólen (9 a 20) participando dos cruzamentos individuais. Portanto, as progênies do ensaio são compostas em sua maioria por meios-irmãos com elevada variabilidade genética, evidenciada pelo alto número de doadores de pólen, e sugere que a seleção para produção de palmito poderá ser baseada nos modelos clássicos de genética quantitativa aplicados para espécies exclusivamente alógamas. Essas informações serão utilizadas para orientar os cruzamentos entre e dentro de progênies/populações. Dois planos de melhoramento são factíveis com essa informação: melhoramento populacional, com cruzamentos entre plantas e acessos altamente divergentes; melhoramento por meio de seleção recorrente recíproca, com a criação de populações divergentes em termos morfométricos e genéticos.

<p>The work in this thesis deals with the ecology and evolution of adaptive individual variation. Ecologists have long used niche theory to describe the ecology of a species as a whole, treating conspecific individuals as ecological equivalent. During recent years, research about individual variation in diet and morphology has gained interest in adaptive radiations and ecological speciation. Such variation among individual niche use may have important conservation implications as well as ecological and evolutionary implications. However, up to date we know very little about the extension of this phenomenon in natural populations and the mechanisms behind it.</p><p>The results in this thesis show that the extension of individual diet specialization is widely spread throughout the animal kingdom. The variation in diet is mainly correlated to morphological variation but not always. Furthermore, this variation in diet and morphology among individuals could be both genetically determined and environmentally induced and it mainly comes from trade-offs in foraging efficiency between different prey types. </p><p>The results from a number of studies of perch also show that individual perch differ in morphology and diet depending on habitat, where littoral perch has a deeper body compared to pelagic perch. This difference in morphology corresponds to functional expectations and is related to foraging efficiency trade-offs between foraging in the littoral and pelagic zone of a lake. The variation in morphology in perch is mainly due to phenotypic plasticity but there are also small genetic differences between the littoral and pelagic perch. Two separate studies show that both predation and competition may be important mechanism for the variation in morphology and diet in perch.</p><p>In conclusion, the results in this thesis show that individual variation in diet and habitat choice is a common phenomenon with lots of ecological and evolutionary implications. However, there are many mechanisms involved in this phenomenon on which we are just about to start learning more about, and only further research in this area will give us the full insight.</p>