Eco-evolutionary dynamics of sexual traits in wild bird populations under changing environment

Principal researcher: Jesús Matínez Padilla.

Period: 2020-2023

The notion that ecology and evolution are intertwined in a short-term has been notorious only in the last few decades, providing a new synthetic and yet in development framework. The concept of eco-evolutionary dynamics aims to understand the interplay between ecology and evolution, either from contemporary evolution to ecological changes (evo-to-eco) or from recent ecological changes to evolutionary change (eco-to-evo). However, the synthetic overview of eco-evolutionary dynamics of phenotypes still has deep caveats. First, unravelling the complex interactions among different sources of evolutionary change that leads adaptive divergence, beyond those driven by natural selection; second, identifying the target phenotypes where selection can act upon and where evolutionary dynamics can be observed and quantified; and third, defining the relative influence of multiple biotic- and non-biotic factors that drives the evolutionary dynamcis. However, adaptive divergence might not be the only evolutionary mechanism that promote population differentiation leading to local adaptation. A key factor that has been identified as key on driving adaptive divergence in populations is gene flow. Gene flow has been suggested as a major source at driving adaptive divergence, but its homogenising or disruptive effect on phenotypes is still controversial. We frame our project on the idea that the role of geneflow on local adaptation is mediated by environmental conditions. We make use of secondary sexual trait in as a target phenotype, since its expression is environment-dependent heritable, selected and evolutionary labile. We place our project in a natural setting where environmental conditions are changing, have a constant but variable flow of immigrant breeders of known and unknown local population and a long-term monitored population for the last 35 years population of a wild bird, the pied flycatcher. By applying a rigorous genetic protocol, we will trace eco-to-evo dynamics of secondary sexual traits using state-of-the-art quantitative genetic techniques making use of genetic pedigrees of 14 generations depth embracing more than 14,000 records. We will tease apart the relative role of different evolutionary mechanisms that promotes local adaptation arising after the action of multiple agents of selection. We will combine observational studies with field based long-term experiments, in which will particularly test the evolutionary trajectories of secondary sexual traits. The expected results will have major implications on how we understand ecological and evolutionary processes of adaptation, with fundamental implications for the origin and maintenance of biodiversity at short temporal scales. In this proposal, we aim obtaining a better comprehension about how animal populations on short-term temporal scales respond to environmental stochasticity, which is of urging importance in the light of recent climate change .

The role of sexual selection and population subdivision in pop persistence in a changing world

Principal researcher: Francisco García González.

Period: 2020-2024

Determining whether sexual selection accelerates or hampers adaptation in novel environments is a central question in evolutionary biology. Resolving this question has important implications for understanding the potential of populations to persist in the face of rapid environmental change. Sexual selection can theoretically facilitate or hinder adaptation to new environments, depending on whether it works as a filter reducing mutational loads, or on whether the negative population-level consequences of sexual conflict are reduced under environmental stress. Few empirical studies have formally tested the alignment or misalignment of sexual and natural selection, and strikingly, no study has explored whether a key ecological and demographical factor such as population spatial structure moderates the effect of sexual selection on adaptation. This project will innovatively investigate the interactive influences of sexual selection (including sexual conflict) and population subdivision on the individuals' and the populations' ability to withstand environmental change. The project will take advantage of the power of experimental evolution to address these questions. It will use selection lines of a pest beetle that have been subject to variation in selection arising from reproductive competition and population spatial structure for over eighty generations, and it will measure a wide array of relevant phenotypic and life-history traits (including lifetime reproductive success, behavioural plasticity, resistance to environmental stressors) and population traits (including population viability and realized extinction events) in response to exposure to environmental disturbances. Sex-specificity underlying evolutionary responses, and the genetic basis providing the potential for evolution will be inspected. In addition, this project will also investigate (both within and outside a context of variation in selection histories), whether non-genetic inheritance via transgenerational effects, and in particularly father-offspring transmission of altered environments, play a role in adaptation to changing environments. Results will inform on whether sexual selection, population spatial structure, their interaction, and transgenerational plasticity, accelerate adaptation, or on the contrary, hinder components of viability selection. Alterations of population spatial structure (e.g., through habitat fragmentation) represent key conservation threats and this work will provide useful empirical data on how these changes may impact key evolutionary processes linked to population viability. This work will in this way provide unique insights into evolutionary and ecological factors affecting extinction risk, but the benefits will not be, therefore, circumscribed to the area of evolutionary biology; they will also have repercussions for conservation biology. Additionally, this research will uncover some of the far-reaching evolutionary implications of transgenerational effects for the evolution of phenotypes and, possibly, population viability. Finally, the project will provide excellent research opportunities for students, and it will also yield useful data for pest control. .

Evolutionary ecology of phenotypic plasticity of morphological, life history and behavioural traits

Principal researcher: Laszlo Garamszegi

Period: 2015-2018

The main interest in evolutionary ecology lies on the variation in phenotypic traits, its link with fitness variation and how these are transferred across generations. This individual variation is not fixed in natural populations but flexibly changes across space and time depending on the prevailing environmental conditions. In factsome traits exhibit consistent variation among individuals, and still remain substantially variable at an individual level. Within an evolutionary point of view, such a dichotomy has been conceptually established by the joined action of selection and heritability of traits (microevolution) or by plastic expression according to the changing environmental circumstances (phenotypic plasticity). However, there is conceptual room to consider trait phenotypic plasticity per se an individual-specific characteristic linked to fitness, and thus susceptible to be selected upon. Such an evolutionary mechanism is yet to be quantified. To understand the evolution and ecology of most phenotypic traits in light of the changing environment, it is now becoming crucial to decompose different variance components and relate these to genetics, physiology and fitness, and also to study how fluctuations in the socio-ecological circumstances shape within- and between-individual (co-)variances. Such tasks are notoriously hard to accomplish in wild animal populations, because they typically necessitate the repetitive sampling of the same individuals under standardized conditions over long periods of time or across large geographic distances. In the current proposal, we aim to accomplish this challenging mission by taking advantage from the long-term studies (over 30 years) of wild populations of two closely related passerine species, the collared and pied flycatchers (Ficedula albicollis and F. hypoleuca) breeding in central and southern Europe, respectively. Using our long-term records in combination with targeted within-individual sampling at a shorter time scale, we will characterize different variance components for different types of traits (morphology, life history and behaviour). Exploiting the temporal and spatial resolution of our study, we will be able to investigate how predictable and unpredictable changes in various socio-ecological contexts (e.g. climate, food supply, predation pressure, demographic patterns, levels of competition) can have microevolutionary consequences for between-year, and between- and within-individual variances as well as for phenotypic plasticity. We will apply a rigorous framework based on quantitative genetics and individual-based models to determine which variance components are attributable to genetic and environmental effects, while we will also establish the evolutionary potential for phenotypic plasticity by exploring the proximate and ultimate mechanisms that can mediate the within-individual variance of different traits. The expected results will have major implications on how we understand ecological and evolutionary processes of adaptation, and how the consistency and plasticity of different phenotypic traits play roles in such processes. Ultimately, our findings will be fundamental for our comprehension of the origin and maintenance of biodiversity both at geographical and temporal scales.

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