Quaking aspen (Populus tremuloides) has the largest natural distribution of any tree native to North America, ranging from Alaska through the breadth of Canada and south to mid-Mexico. The Laurentide ice sheet occupied most of the current range of P. tremuloides until the late Pleistocene epoch, so this species has undergone a significant, geologically recent range expansion. Surprisingly, range-wide patterns of genetic variation in P. tremuloides have never been described. Using a sample set representing the full longitudinal and latitudinal extent of the species distribution, I have conducted a phylogeographic analysis for P. tremuloides. Preliminary results comparing both nuclear and chloroplast DNA sequences revealed surprisingly low levels of divergence across the range. Because of this remarkably shallow genetic divergence among aspen populations, I used a set of rapidly-evolving molecular markers (microsatellites) to describe patterns of gene flow and diversity and to correlate those patterns with landscape features and histories. I analyzed eight microsatellite loci in 794 individuals from 30 sampling sites. From this multilocus data set, I identified pronounced genetic structuring across the range. Strikingly, sampling sites representing the southwestern portion of the range, the western United States and Mexico, form a distinct cluster. Sites within this southwestern cluster display dramatically reduced within-site genetic diversity but elevated regional genetic diversity, which suggests that populations in the southwestern portion of the range make up a stable edge persisting through multiple climate oscillations. Based on the uniqueness of the southwestern cluster and the climatic differences between the southwest and northern portions of the range, I propose that the southwestern cluster may represent a distinct ecotype. I also identified hotspots of diversity that correspond with potential refugia during the last glacial maximum but additional work is needed to refine these patterns. Further, my findings provide a solid foundation for a range of future studies on adaptive genetic and trait variation in this species.

Proechimys is a genus of the family Echimyidae with wide distribution in the Neotropical region. Although it is abundant and widely distributed, this genus is little studied and has its taxonomy and systematics little solved. This lack of knowledge impairs studies in other areas, especially in ecology, since the species are externally similar, becoming the identification in the field and museums more difficult. There are few published studies with morphological and genetic variation, and on systematics of the genus Proechimys. The aim of this Thesis was to propose a phylogeny based on genomic data and to delimit the species of the genus, also using other dataset such as the morphometric, to better understand the diversification and evolution of Proechimys, especially in the Western Amazon. During the Ph.D. project, I identified in morphotypes and geo- referenced the localities of 3,104 Proechimys specimens in 18 museums and collections in Brazil, the USA and England, and evaluated the morphological variation from 22 quantitative characters in 1,503 specimens, and 58 qualitative characters of skull and skin in 315 specimens. In this thesis I will present the morphometric results of 479 adult specimens. The remaining morphometric and morphological data are still being studied for future publications. In addition, I sequenced part of the genome of 278 specimens using the ddRAD-seq technique to evaluate the genetic variation. Chapter 1 is a general introduction in which I presented the taxonomic history of the genus, the current knowledge on the evolutionary history of Proechimys, and remarks on the landscape evolution in Western Amazon. In addition, I discussed on species concepts and Integrative Taxonomy, themes that were addressed in this thesis. In Chapter 2, I proposed a genomic phylogeny based on genomic data, identified the clades and tested whether they could be considered different species based on the multispecies coalescent model for genetic data and Brownian motion for morphometric data. The phylogenetic relationships recovered among Proechimys individuals indicated five main clades within the genus, with statistical support for the recognition of at least 28 lineages at the species level. Proechimys was not recovered as monophyletic, and 12 of the 28 lineages did not correspond to currently valid species; some of them may be new taxa, while others may be revalidations of taxa currently included in the synonymy of valid species. In Chapter 3, I estimated divergence times between the clades and tested Bayesian models of geographic range evolution to indicate ancestral areas for the clades. With these results I created a biogeographic hypothesis for the evolution of Proechimys. The genus origin was estimated in the Miocene and in the Western Amazon. I was able to associate the biogeographic history to the landscape evolution of the Amazon. Diversification within the five main clades occurred in the Pliocene and Pleistocene. In Chapter 4, I evaluated the phylogeographic pattern of three sympatric species of Proechimys from the Western Amazon: : Proechimys brevicauda, Proechimys simonsi and Proechimys steerei. The aim was to test whether these species sharing the same geographic space would also share the same patterns of genetic structure or whether there would be segregation at the microhabitat level that would lead to different phylogeographic patterns. For this I calculated the overlap and similarity among their environmental and morphological hypervolumes, and tested the importance of barriers, the geographic and environmental distance between populations in each species to explain the genetic structure. Each species showed little overlap of the morphological hypervolume, and great overlap in the environmental one. In addition, they presented different genetic structure patterns, showing that even though they are congeners species and occur in sympatry, they may respond differently to landscape evolution, and to environmental changes. In Chapter 5, I present a synthesis of the main conclusions and future perceptives about the study of genus and the implications of my 15 results for the conservation and studies on diversity patterns in the Amazon region. Thus, this Thesis increased the knowledge on factors that lead to the genetic structure of mammalian species in the Amazon, as well as on the evolutionary history of the genus Proechimys and its genetic, morphological and species diversity. These results may support future studies in ecology, conservation biology and also fauna surveys in the Neotropical region. / Proechimys é um gênero da família Echimyidae com ampla distribuição na região Neotropical. Embora seja abundante e amplamente distribuído, este gênero é pouco estudado e tem sua taxonomia e sistemática pouco resolvida. Essa falta de conhecimento dificulta estudos em outras áreas, especialmente em ecologia, uma vez que as espécies são externamente semelhantes, tornando complexa a identificação de indivíduos no campo e nos museus. Existem poucos estudos publicados com variação morfológica e genética, e também sobre a sistemática de Proechimys. O objetivo desta tese foi propor uma filogenia baseada em dados genômicos e delimitar as espécies do gênero, utilizando também outros bancos de dados como o morfométrico, para entender melhor a diversificação e evolução de Proechimys, especialmente na Amazônia Ocidental. Durante o projeto de doutorado, eu identifiquei em morfotipos e fiz o georreferenciamento das localidades de 3.104 espécimes de Proechimys em 18 museus e coleções do Brasil, Estados Unidos da América e Inglaterra, e avaliei a variação morfológica de 22 caracteres quantitativos em 1.503 espécimes, e 58 caracteres qualitativos de crânio e pele em 315 espécimes. Nesta tese eu vou apresentar os resultados oriundos de uma parte dos dados morfométricos, de 479 espécimes adultos. Os demais dados morfométricos e morfológicos ainda estão sendo trabalhados para futuras publicações. Além disso, sequenciei parte do genoma de 278 espécimes usando a técnica ddRAD-seq para avaliar a variação genética. O Capítulo 1 diz respeito a uma introdução geral na qual eu apresentei a história taxonômica do gênero, o conhecimento atual sobre a história evolutiva de Proechimys e fiz um breve comentário sobre a evolução da paisagem da Amazônia Ocidental. Além disso, eu discuti sobre alguns conceitos de espécies e sobre a Taxonomia Integrativa, temas que foram abordados nessa tese. No Capítulo 2, propus uma filogenia para o gênero baseada em dados genômicos, identifiquei os clados e testei se eles poderiam ser considerados espécies diferentes com base no modelo coalescente multiespecífico para dados genéticos e no movimento Browniano para dados morfométricos. As relações filogenéticas recuperadas entre os indivíduos de Proechimys recuperaram cinco grandes clados dentro do gênero, com suporte estatístico para o reconhecimento a nível de espécie de pelo menos 28 linhagens. Proechimys não foi recuperado como monofilético e 12 das 28 linhagens não corresponderam a espécies válidas atualmente; algumas delas podem ser novos táxons, enquanto outras podem ser revalidações de táxons atualmente incluídas na sinonímia de espécies válidas. No Capítulo 3, eu datei os tempos de divergência entre os clados e testei modelos bayesianos de evolução da distribuição geográfica para estimar as áreas ancestrais dos clados. Com esses resultados, eu criei uma hipótese biogeográfica para a evolução do gênero. A origem do gênero foi estimada para o Mioceno, na Amazônia Ocidental e foi possível associar a história evolutiva do gênero com mudanças na paisagem da Amazônia. A diversificação dentro dos 5 principais clados do gênero ocorreu no Plioceno e no Pleistoceno. No Capítulo 4, eu avaliei o padrão filogeográfico de três espécies simpátricas de Proechimys da Amazônia Ocidental: Proechimys brevicauda, Proechimys simonsi e Proechimys steerei. O objetivo foi testar se essas espécies que compartilham o mesmo espaço geográfico, compartilhariam também os mesmos padrões de estruturação genética, ou se haveria uma segregação ao nível de micro-habitat que levaria a diferentes padrões filogeográficos. Para isso eu calculei a sobreposição dos hipervolumes ambiental e morfológicos e testei a importância de barreiras, da distância geográfica e ambiental entre as populações de cada espécie para explicar a estruturação genética. Cada uma das três espécies simpátricas mostrou pouca sobreposição do hipervolume morfológico, e grande sobreposição no ambiental. Cada espécie teve um padrão de estruturação genética diferente, mostrando que mesmo ocorrendo em simpatria e sendo espécies congêneras, elas respondem de 13 formas diferentes à evolução da paisagem e às mudanças ambientais. No Capítulo 5, eu apresento uma síntese com as principais implicações dessa tese para diferentes áreas relacionadas à Ecologia Aplicada e as perceptivas futuras sobre o estudo do gênero. Dessa forma, esta tese ampliou o conhecimento sobre os fatores que levam à estruturação genética de espécies de mamíferos da Amazônia, bem como sobre a história evolutiva do gênero Proechimys e de sua diversidade genética, morfológica e de espe?ies. Estes resultados podem auxiliar trabalhos em ecologia, biologia da conservação e também nos levantamentos de fauna em grande parte da região Neotropical.

<p>The great difference in the level of chloroplast variation and its geographic structure among the three main species studied here demonstrates that forest species do not form a homogeneous group. Hazel shows a genetic structure similar to many other thermophilous species and this structure, in combination with fossil evidence, indicates that the post-glacial colonisation of most of Europe originated in a refugium in western France while the Balkan and Italy were colonised from a south-eastern refugium.</p><p>In sallow and silver birch the chloroplast DNA variation and its structure does not fit with a scenario of glacial restriction to southern refugia and survival at intermediate latitudes is suggested for both species. The chloroplast DNA variation in silver birch suggests the presence of one western and one eastern European post-glacial colonisation route and limited contribution of southern populations in the colonisation of the rest of Europe. Unique haplotypes by the Ural Mountains indicates the possibility of a separate glacial origin of these populations.</p><p>The study of chloroplast DNA in species closely related to sallow and silver birch indicate that extensive hybridisation and cytoplasmic gene flow occurs within both the Salix and Betula genera in Europe. The nuclear and chloroplast phylogenies of 14 Betula species were not in complete agreement with each other or with the classical division of the Betula genus into subgenera or sections. The phylogenetic structure implies that hybridisation has played a role in the evolution of the Betula genus.</p><p>This thesis focuses on the chloroplast DNA variation in three forest tree genera: Corylus, Betula and Salix. Chloroplast PCR-RFLP is used to evaluate the post-glacial history of hazel, Corylus avellana, silver birch, Betula pendula and sallow, Salix caprea and to explore the possibility of introgression in the Salix and Betula genera. In addition, the chloroplast matK gene, its flanking regions and the nuclear ADH gene were used to study the phylogenetic relationships within the Betula genus.</p>

<p>The phylogeography of a wide ranging temperate species, the adder, <i>Vipera berus</i>, was investigated using several genetic tools, with special emphasis on the post-glacial colonisation pattern of Fennoscandia. The area was colonised from two directions by adder populations representing different glacial refugia. The two populations meet in three places and the main contact zone is situated in Northern Finland. The two other contact zones are the result of dispersal across the Baltic Sea to the Umeå archepelago and South-Western Finland. Asymmetrically distributed nuclear genetic variation compared to mitochondrial DNA in the northern contact zone suggests a skewed gene flow from the east to the west across the zone. This pattern might reflect differences in dispersal among sexes and lineages, or may be accounted for by a selective advantage for nuclear variation of eastern origin among Fennoscandian adders.</p><p>The phylogeographic pattern for adders across the entire species range was addressed by sequencing part of the mitochondrial genome and scoring microsatellite markers. The adder can be divided into three major genetic groups. One group is confined to the Balkan peninsula harbouring the distribution range of <i>V. b. bosniensis</i>. A second, well differentiated group is restricted to the Southern Alps. These two areas have probably served as refugia for adders during a number of ice ages for the adders. The third group is distributed across the remainder of the species’ range, from extreme Western Europe to Pacific Russia and can be further divided into one ancestral group inhabiting the Carpathians refugial area, and three more recent groups inhabiting areas west, north and east of the Alps. The adder provides an example of a species where the Mediterranean areas are housing endemic populations, rather than the sources for post-glacial continental colonisation. Continent-wide colonisation has instead occurred from up to three cryptic northern refugia. </p>

<p>The aim of this thesis is to study phylogeny, species-wide phylogeography and genetic diversity in <i>Formica</i> ants across Eurasia in connection with the history of biotic responses to Quaternary environmental changes.</p><p>The mitochondrial DNA phylogeny of Palaearctic <i>Formica</i> species supported the subgeneric grouping based on morphological similarity. The exception was that <i>F. uralensis</i> formed a separate phylogenetic group. The mitochondrial DNA phylogeny of the <i>F. rufa </i>group showed the division into three major phylogenetic groups: one with the species <i>F. polyctena</i> and <i>F. rufa</i>, one with <i>F. aquilonia</i>, <i>F. lugubris</i> and <i>F. paralugubris</i>, and the third one with <i>F. pratensis</i>.</p><p>West-east phylogeographic divisions were found in <i>F. pratensis</i> suggesting post-glacial colonization of western Europe and a wide area from Sweden to the Baikal Lake from separate forest refugia. In contrast, no phylogeographic divisions were detected in either <i>F. lugubris </i>or<i> F. exsecta</i>. Contraction of the distribution range to a single refugial area during the late Pleistocene and the following population expansion could offer a general explanation for the lack of phylogeographic structure across most of Eurasia in these species.</p><p>Sympatrically distributed and ecologically similar species <i>F. uralensis </i>and<i> F. candida</i> showed clear difference in the phylogeographic structure that reflected difference in their vicariant history. Whereas no phylogeographic divisions were detected in <i>F. uralensis</i> across Europe, <i>F. candida</i> showed a well-supported phylogeographic division between the western, the central and the southern group.</p><p>In socially polymorphic <i>F. cinerea</i>, the overall level of intrapopulation microsatellite diversity was relatively high and differentiation among populations was low, indicating recent historical connections. The lack of correspondence between genetic affinities and geographic locations of studied populations did not provide any evidence for differentiating between alternative hypotheses concerning the directions and sources of postglacial colonization of Fennoscandia.</p>

<p>The white-tailed eagle is a formerly threatened raptor that is commonly used as a flagship and indicator species in conservation work. This thesis uses molecular genetic methods to study sex determination of nestlings, genetic variability, population structure and phylogeography of the white-tailed eagle.</p><p>Fourteen microsatellite markers were developed and tested for the white-tailed eagle.</p><p>A method to sex white-tailed eagle nestlings in the field is presented. The method is based on just one tarsus measure, and is suitable for situations where a single person is handling the nestlings alone in a treetop.</p><p>Most European white-tailed eagle populations underwent extreme declines during the 20th century. The results presented here show that bottlenecked populations have maintained significant levels of genetic diversity. Gene flow between regions is not a main explanation for this, as indicated by both genetic and ringing data. Instead, the long generation time of white-tailed eagles has acted as an intrinsic buffer against rapid loss of genetic diversity. Additionally, local conservation led to protection of more genetic diversity than if conservation had focused on the large remnant population in Norway.</p><p>Mitochondrial DNA of white-tailed eagles is structured in two main clades with a predominantly eastern and western Eurasian distribution. The clades likely correspond to separate Ice Age refugia but do not grant classification as evolutionary significant units given their current extensive overlap across large parts of Eurasia.</p><p>Microsatellite variation was studied in populations across Eurasia. Variability was rather constant across the continent, but clearly lower on Iceland and Greenland. This is best explained by founder effects during their colonisation, but only weak bottlenecks during colonisation of and persistence on the continent. Current population differentiation between Europe and eastern Eurasia is not compatible with a zero gene flow model but requires some amount of gene flow over evolutionary time scales.</p>

<p>Genetic variation within and among populations is a result of past and ongoing processes. Among the most important of such processes are dispersal, habitat fragmentation and selection. This thesis use neutral genetic variation as a tool to investigate these processes in three bird species.</p><p>In the Siberian jay, the timing of dispersal is dependent on social dominance among siblings. Mark-recapture data, radio-tracking and genetic variation was used to investigate whether timing of dispersal had an effect on dispersal distance. The results show that early dispersing individuals also disperse longer. In the same species, genetic correlation between neighbours was used to find areas with high production of philopatric individuals, which could be indicative of high habitat quality.</p><p>Great snipe populations in northern Europe have a breeding range divided into two regions. A Q_ST-F_STapproach was applied to study variation in selection between regions. Differentiation between the regions in neutral molecular markers was low, indicating high gene flow, or short time available for neutral divergence. Morphological divergence between the regions was high, and Q_ST > F_ST, which indicates divergent selection. Thus, neutral genetic markers can be misleading in identifying evolutionary significant units, and the Q_ST-F_ST approach might be valuable to identify targets for conservation.</p><p>Rock ptarmigan, or its ancestors, originated in Beringia, and spread throughout the Holarctic region. Their distribution has subsequently been affected by glaciations, most likely leading to withdrawals and re-colonisations. Neutral genetic variation among five populations around the northern Atlantic was investigated. There was strong genetic structure among the populations, and evidence that Scandinavian rock ptarmigan has been isolated from other populations for considerable time. Rock ptarmigan in Svalbard showed slightly lower genetic variation than others, and comparisons with other studies suggested an eastern colonisation route to Svalbard.</p>

Whether microevolutionary processes can explain macroevolutionary patterns has long been a matter of contentious debate. The debate has persisted largely because of the challenging task of connecting microevolutionary theory, which examines population-level phenomena on the generation scale, to data collected across larger spatial and temporal scales. My dissertation research broadly examines phenotypic evolution across multiple scales by connecting microevolutionary theory to macroevolutionary phenomena such as speciation and large-scale phenotypic change. In particular, I focus on the so-called "paradox of stasis"; which wrestles with the apparent conflict between frequently-observed cases of rapid evolution on short timescales and the frequent appearance of stasis in the fossil record. I attempt to link micro and macroevolution by using the theoretical framework of evolutionary quantitative genetics for modeling the effects of drift and selection. My four dissertation chapters examine four different systems (1) connecting quantitative genetic models of sexual selection to speciation (2) connecting microevolutionary and macroevolutionary body size data across scales of time (3) using phylogenetic comparative methods and quantitative genetic models to examine the evolution of a classic example of stasis, mammalian body temperature and (4) finally, using multi-locus phylogeography to understand the evolutionary processes that contribute to the diversification of a widespread snake across broad spatial scales. In chapter 2, I demonstrate that genetic drift combined with sexual selection can promotes speciation and diversification of male ornaments. Furthermore, I demonstrate that drift promotes the evolution of elaborate ornaments even when preferences are costly. In chapter 3, I combine data from microevolutionary field studies, the fossil record, and phylogenetic comparative data into a single analytical framework to resolve apparent conflicts between micro and macroevolutionary patterns. To do so, I compiled and analyzed the largest database of phenotypic divergence data in existence. I demonstrate that patterns of stasis persist until a million-year threshold, after which divergence begins to accumulate in a time-dependent manner. This pattern is best fit with a hierarchical model that describes evolution as occurring in bursts on the million-year timescale, but that allows for rapid, but bounded, evolution on short timescales. In chapter 4, I demonstrate that mammalian body temperature -- which has been previously presented as a classic example of stasis -- does in fact evolve extensively across the mammalian radiation (albeit slowly). Furthermore, I show that mammalian body temperature evolves in response to changing environmental conditions. Finally, I evaluate the role that genetic constraints play in the apparent slowness of body temperature evolution. In chapter 5, I examine a well-studied empirical system of garter snakes in which a strong signature of stabilizing selection has been found for phenotypic traits. Using multiple mitochondrial and nuclear loci, I show that introgression is rampant between species, and dynamic patterns of range expansion, contraction, and introgression among clades have led to a complex pattern of genetic variation. This structure of genetic variation underscores the need to examine range-wide processes for generating phenotypic divergence across clades. Overall, these chapters suggest that apparent disconnects between microevolutionary processes and macroevolutionary patterns could be explained by the scaling of population-level theory over large spatial and temporal scales. / Graduation date: 2013 / Access restricted to the OSU Community at author's request from Oct. 25, 2012 - Oct. 25, 2013

The great difference in the level of chloroplast variation and its geographic structure among the three main species studied here demonstrates that forest species do not form a homogeneous group. Hazel shows a genetic structure similar to many other thermophilous species and this structure, in combination with fossil evidence, indicates that the post-glacial colonisation of most of Europe originated in a refugium in western France while the Balkan and Italy were colonised from a south-eastern refugium. In sallow and silver birch the chloroplast DNA variation and its structure does not fit with a scenario of glacial restriction to southern refugia and survival at intermediate latitudes is suggested for both species. The chloroplast DNA variation in silver birch suggests the presence of one western and one eastern European post-glacial colonisation route and limited contribution of southern populations in the colonisation of the rest of Europe. Unique haplotypes by the Ural Mountains indicates the possibility of a separate glacial origin of these populations. The study of chloroplast DNA in species closely related to sallow and silver birch indicate that extensive hybridisation and cytoplasmic gene flow occurs within both the Salix and Betula genera in Europe. The nuclear and chloroplast phylogenies of 14 Betula species were not in complete agreement with each other or with the classical division of the Betula genus into subgenera or sections. The phylogenetic structure implies that hybridisation has played a role in the evolution of the Betula genus. This thesis focuses on the chloroplast DNA variation in three forest tree genera: Corylus, Betula and Salix. Chloroplast PCR-RFLP is used to evaluate the post-glacial history of hazel, Corylus avellana, silver birch, Betula pendula and sallow, Salix caprea and to explore the possibility of introgression in the Salix and Betula genera. In addition, the chloroplast matK gene, its flanking regions and the nuclear ADH gene were used to study the phylogenetic relationships within the Betula genus.

The phylogeography of a wide ranging temperate species, the adder, Vipera berus, was investigated using several genetic tools, with special emphasis on the post-glacial colonisation pattern of Fennoscandia. The area was colonised from two directions by adder populations representing different glacial refugia. The two populations meet in three places and the main contact zone is situated in Northern Finland. The two other contact zones are the result of dispersal across the Baltic Sea to the Umeå archepelago and South-Western Finland. Asymmetrically distributed nuclear genetic variation compared to mitochondrial DNA in the northern contact zone suggests a skewed gene flow from the east to the west across the zone. This pattern might reflect differences in dispersal among sexes and lineages, or may be accounted for by a selective advantage for nuclear variation of eastern origin among Fennoscandian adders. The phylogeographic pattern for adders across the entire species range was addressed by sequencing part of the mitochondrial genome and scoring microsatellite markers. The adder can be divided into three major genetic groups. One group is confined to the Balkan peninsula harbouring the distribution range of V. b. bosniensis. A second, well differentiated group is restricted to the Southern Alps. These two areas have probably served as refugia for adders during a number of ice ages for the adders. The third group is distributed across the remainder of the species’ range, from extreme Western Europe to Pacific Russia and can be further divided into one ancestral group inhabiting the Carpathians refugial area, and three more recent groups inhabiting areas west, north and east of the Alps. The adder provides an example of a species where the Mediterranean areas are housing endemic populations, rather than the sources for post-glacial continental colonisation. Continent-wide colonisation has instead occurred from up to three cryptic northern refugia.