Eurasian Reed Warbler (Acrocephalus scirpaceus) is a long-distance migrant wintering in sub-Saharan Africa and breeding in reedbeds of the Western Palaearctic. European populations migrate in two main directions (SW and SE). Though there is little morphological variation across the breeding range, Asian populations are traditionally separated from the nominate subspecies as the subspecies fuscus. My aim was to explore genetic differentiation among Eurasian Reed Warbler populations in respect to the factors which may have influenced the genetic diversity and divergence of the populations, such as a migratory divide, high migratory connectivity or isolation by distance. I used samples of 495 individuals from 36 populations across the breeding range using microsatellites. Pairwaise fixation indexes FST showed significant differences among populations from the Iberian peninsula, Finland and the Middle East and the rest of populations. Exact tests of differentiation did not confirm non-random distribution between pairs of populations. Overall FST was statistical significant but very small (FST = 0,018). Analysis of molecular variance (AMOVA) revealed that 98% of variation was ascribable to variability of allele frequencies within populations. On the other hand, differences between populations contributed to overall variation with only 2%. Isolation by distance showed only weak relationship between geographical and genetic distances. Main analysis using Bayesian clustering approach implemented in software Structure 2.2. detected no genetic structure of population. Sampled Eurasian Reed Warbler populations seem to form one genetic population. Relatively low genetic diversification indicates large dispersal potential of the studied Reed Warbler populations, when gene flow successfully counters differentiation of population irrespective of large breeding area and high migrate connectivity between breeding and wintering area.

<p dir="ltr">Spotted Turtle (Clemmys guttata) populations are declining dramatically across their range primarily due to habitat alteration, fragmentation, and reduction. Fragmented habitats have the potential to affect a population’s genetic diversity and size through the direct loss of individuals and the reduction of gene flow. Understanding genetic variation in Spotted Turtles can provide insight into population dynamics, the geographic distribution of genetic variants, and conservation needs. I examined the genetic variation in Spotted Turtle populations across the western portion of their geographic range including localities in Illinois, Indiana, Ohio, Michigan, and Ontario, Canada. Using blood samples collected during the 2022 and 2023 field seasons as well as previously collected tissues, I genotyped 611 individuals across 17 or more localities using 16 microsatellite loci. Five of 17 sites across the geographic extent of the sample suggested the presence of inbreeding (positive Fis values). Although the precision of estimates was low in most localities (10 of 17 with incalculable confidence intervals), the remaining localities in Ohio were estimated to have effective population sizes of < 20 individuals. Model-based and ordination-based clustering were conducted to assess population structure. Both types of clustering approaches identified four genetic clusters within the dataset. The two Illinois sites fell distinctly into their own cluster, whereas all other sites show a pattern of admixture. Despite these clustering results, incorporation of spatial information in principal component analysis (sPCA), shows that genetic composition gradually changes from west to east across the landscape, a pattern supported by isolation by distance using a Mantel test of the correlation between genetic and geographic distances. My results show that several Spotted Turtle populations have low levels of genetic variation and could benefit from augmentation. The observed pattern of isolation by distance 9 suggests that any translocations of turtles to support populations should be attempt to draw from viable populations that are in closer proximity.</p>

Orientadores: Vera Nisaka Solferini, Ronaldo Bastos Francini / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-15T11:47:43Z (GMT). No. of bitstreams: 1 Ramos_RenatoRogner_D.pdf: 2883716 bytes, checksum: eac9d7277bf9ba106da8bdf2bc840994 (MD5) Previous issue date: 2010 / Resumo: Espécies com distribuições continentais podem ocupar várias zonas climáticas e diferentes vegetações, e forças seletivas locais podem gerar diferenças entre populações. A borboleta Heliconius erato phyllis possui esse tipo de distribuição e o teste G revelou diferenças significativas nos padrões de coloração das asas anteriores entre machos de diferentes regiões, mas não entre fêmeas. Melanismo, seleção sexual, atividade hormonal e predação podem estar envolvidos. O número de raios vermelhos nas asas posteriores apresentou correlação positiva com o comprimento das asas anteriores (CAA), mas exceções sugerem que tamanho e temperatura atuem como ativadores de hormônios que elevam a concentração de pigmentos para a formação dos raios. ANOVA demonstrou médias do CAA diferentes entre as populações, e o teste de Tukey apontou os maiores indivíduos em 3 sítios costeiros. Uma análise de componentes principais apontou altas temperaturas, pluviosidade e estabilidade climática como fatores ligados ao grande CAA. Esses fatores possivelmente contribuem com o crescimento de hospedeiras e com o desempenho larval. Técnicas moleculares usando marcador microssatélite foram aplicadas nas populações, em três escalas geográficas e uma temporal. Os resultados mostram grande variabilidade genética e populações sem isolamento por distância em escala continental. A reprodução é panmítica e os indivíduos possuem alta capacidade de dispersão mesmo entre fragmentos urbanos. Na escala temporal ocorreram diferenças estruturais moderadas, provavelmente devido a gargalos. Estudos em populações fragmentadas e de ampla distribuição ajudam a entender os efeitos do isolamento sobre a estrutura genética dessas populações e propor planos de manejo e conservação. / Abstract: Species with continental distribution can take several climatic zones and different vegetations, and local selective forces can generate differences among populations. The Heliconius erato phyllis butterfly has this kind of distribution, and the ?G? test showed meaningful differences on forewing color-patterns among males from different regions, but not among females. Melanism, sexual selection, hormonal activity and predation may be involved. The number of red raylets on hindwing show positive correlation with forewing's length (CAA), but exceptions suggest that size and temperature as triggers hormones that raise the concentration of pigments in the formation of raylets. The ANOVA showed different average on CAA among populations and the Tukey's test showed greatest individuals on 3 coastline sites. A principal component analysis indicated high temperatures, rainfall and climatic stability as major factors responsible for the large CAA. These factors possibly contribute with the growth of host-plant and the larval performance. Molecular techniques using microsatellite marker were applied on populations under three geographic scales and one temporal scale. The results show has a great genetic variability and populations without isolation by distance on continental scale. The reproduction is panmitic and the individuals have high dispersal ability even among urban fragments. On the temporal scale occurred moderate structural differences; probably due to bottlenecks. Studies on widespread and fragmented populations, help to understand the effects of isolation over the genetic structure of populations, and propose management and conservation plans. / Doutorado / Ecologia / Doutor em Ecologia