Publicação
Assessing the speciation continuum in Timon lepidus
| Resumo: | Understanding speciation requires the integration of ecology, evolution and the role of history in shaping the diversification or decline of lineages. To gain understanding on how variation is generated and maintained within and between natural populations, we must understand both how variation in phenotype may affect the fitness of individuals in their local environment, and how natural selection is shaping the genome of those organisms. Next generation sequencing together with new analytical approaches have fundamentally changed the scope of studies of non-model organisms and thus, the available tools to answer long-standing questions underwent remarkable evolution. We are now, more than ever before, equipped to establishing missing links between phenotype, genotype and environment, which will provide a detailed picture of the adaptive evolutionary process. Studies of the genomics of speciation along the speciation continuum are emerging in several non-model organisms, mainly where speciation is driven by ecology and divergent selection. The present study was the first applying RAD-Seq to natural populations of Timon lepidus, which allowed the analysis of thousands of polymorphic molecular markers simultaneously, across this lizard’s genome. The objective was to assess the putative incipient process of speciation between two subspecies, and further understand how populations adaptively diverge in heterogeneous environments. The SNP data generated allowed us to address different scopes of T. lepidus evolutionary history, allowing the assessment of the population genomics of this species considering differently acting evolutionary forces. The main pattern of divergence between populations reflects local adaptation rather than the expected incipient speciation pattern accordant with taxonomy, and further evidence of local adaptation and repeated ecological evolution are provided both by genomic and environmental information of this species. Phenotype assessment proved to be inconclusive regarding the taxonomic arrangement of populations and additional research should uncover this patterns. Therefore, the current taxonomy should be reviewed in the light of the speciation continuum, taking into account the pattern of local adaptation expressed by these populations. |
|---|---|
| Autores principais: | Laurentino, Telma Guedes |
| Assunto: | Especiação Adaptação local Evolução Timon lepidus Sequenciação de nova geração Subespécie Teses de mestrado - 2015 |
| Ano: | 2015 |
| País: | Portugal |
| Tipo de documento: | dissertação de mestrado |
| Tipo de acesso: | acesso aberto |
| Instituição associada: | Universidade de Lisboa |
| Idioma: | inglês |
| Origem: | Repositório da Universidade de Lisboa |
| Resumo: | Understanding speciation requires the integration of ecology, evolution and the role of history in shaping the diversification or decline of lineages. To gain understanding on how variation is generated and maintained within and between natural populations, we must understand both how variation in phenotype may affect the fitness of individuals in their local environment, and how natural selection is shaping the genome of those organisms. Next generation sequencing together with new analytical approaches have fundamentally changed the scope of studies of non-model organisms and thus, the available tools to answer long-standing questions underwent remarkable evolution. We are now, more than ever before, equipped to establishing missing links between phenotype, genotype and environment, which will provide a detailed picture of the adaptive evolutionary process. Studies of the genomics of speciation along the speciation continuum are emerging in several non-model organisms, mainly where speciation is driven by ecology and divergent selection. The present study was the first applying RAD-Seq to natural populations of Timon lepidus, which allowed the analysis of thousands of polymorphic molecular markers simultaneously, across this lizard’s genome. The objective was to assess the putative incipient process of speciation between two subspecies, and further understand how populations adaptively diverge in heterogeneous environments. The SNP data generated allowed us to address different scopes of T. lepidus evolutionary history, allowing the assessment of the population genomics of this species considering differently acting evolutionary forces. The main pattern of divergence between populations reflects local adaptation rather than the expected incipient speciation pattern accordant with taxonomy, and further evidence of local adaptation and repeated ecological evolution are provided both by genomic and environmental information of this species. Phenotype assessment proved to be inconclusive regarding the taxonomic arrangement of populations and additional research should uncover this patterns. Therefore, the current taxonomy should be reviewed in the light of the speciation continuum, taking into account the pattern of local adaptation expressed by these populations. |
|---|