@article{17238,
  abstract     = {We know that heritable variation is abundant, and that selection causes all but the smallest populations to rapidly shift beyond their original trait distribution. So then, what limits the range of a species? There are physical constraints and also population genetic limits to the effectiveness of selection, ultimately set by population size. Global adaptation, where the same genotype is favoured over the whole range, is most efficient when based on a multitude of weakly selected alleles and is effective even when local demes are small, provided that there is some gene flow. In contrast, local adaptation is sensitive to gene flow and may require alleles with substantial effect. How can populations combine the advantages of large effective size with the ability to specialise into local niches? To what extent does reproductive isolation help resolve this tension? I address these questions using eco-evolutionary models of polygenic adaptation, contrasting discrete demes with continuousspace.},
  author       = {Barton, Nicholas H},
  issn         = {1420-9101},
  journal      = {Journal of Evolutionary Biology},
  number       = {6},
  pages        = {605--615},
  publisher    = {Oxford University Press},
  title        = {{Limits to species' range: The tension between local and global adaptation}},
  doi          = {10.1093/jeb/voae052},
  volume       = {37},
  year         = {2024},
}

@article{17237,
  abstract     = {The impact of climate change on populations will be contingent upon their contemporary adaptive evolution. In this study, we investigated the contemporary evolution of 4 populations of the cold-water kelp Laminaria digitata by analyzing their spatial and temporal genomic variations using ddRAD-sequencing. These populations were sampled from the center to the southern margin of its north-eastern Atlantic distribution at 2 time points, spanning at least 2 generations. Through genome scans for local adaptation at a single time point, we identified candidate loci that showed clinal variation correlated with changes in sea surface temperature (SST) along latitudinal gradients. This finding suggests that SST may drive the adaptive response of these kelp populations, although factors such as species’ demographic history should also be considered. Additionally, we performed a simulation approach to distinguish the effect of selection from genetic drift in allele frequency changes over time. This enabled the detection of loci in the southernmost population that exhibited temporal differentiation beyond what would be expected from genetic drift alone: these are candidate loci which could have evolved under selection over time. In contrast, we did not detect any outlier locus based on temporal differentiation in the population from the North Sea, which also displayed low and decreasing levels of genetic diversity. The diverse evolutionary scenarios observed among populations can be attributed to variations in the prevalence of selection relative to genetic drift across different environments. Therefore, our study highlights the potential of temporal genomics to offer valuable insights into the contemporary evolution of marine foundation species facing climate change.},
  author       = {Reynes, Lauric and Fouqueau, Louise and Aurelle, Didier and Mauger, Stephane and Destombe, Christophe and Valero, Myriam},
  issn         = {1420-9101},
  journal      = {Journal of Evolutionary Biology},
  number       = {6},
  pages        = {677--692},
  publisher    = {Oxford University Press},
  title        = {{Temporal genomics help in deciphering neutral and adaptive patterns in the contemporary evolution of kelp populations}},
  doi          = {10.1093/jeb/voae048},
  volume       = {37},
  year         = {2024},
}

@inproceedings{18922,
  abstract     = {Let G be a directed graph with m edges and n vertices. We present a deterministic linear-time algorithm for computing the 3-edge-connected components of G. This is a significant improvement over the previous best bound by Georgiadis et al. [SODA 2023], which is Õ(m√{m}) and randomized. Our result is based on a novel characterization of 2-edge cuts in directed graphs and on a new technique that exploits the concept of divergent spanning trees and 2-connectivity-light graphs, and requires a careful modification of the minset-poset technique of Gabow [TALG 2016]. As a side result, our new technique yields also an oracle for providing in constant time a minimum edge-cut for any two vertices that are not 3-edge-connected. The oracle uses space O(n) and can be built in O(mlog n) time: given two query vertices, it determines in constant time whether they are 3-edge-connected, or provides a k-edge cut, with k≤ 2, that separates them.},
  author       = {Georgiadis, Loukas and Italiano, Giuseppe F. and Kosinas, Evangelos},
  booktitle    = {65th Annual Symposium on Foundations of Computer Science},
  isbn         = {9798331516741},
  location     = {Chicago, IL, United States},
  pages        = {62--85},
  publisher    = {IEEE},
  title        = {{Computing the 3-edge-connected components of directed graphs in linear time}},
  doi          = {10.1109/focs61266.2024.00015},
  year         = {2024},
}

@article{17207,
  author       = {Fouqueau, Louise and Polechova, Jitka},
  issn         = {1420-9101},
  journal      = {Journal of evolutionary biology},
  number       = {6},
  pages        = {579--587},
  publisher    = {Oxford University Press},
  title        = {{Eco-evolutionary dynamics in changing environments: Integrating theory with data}},
  doi          = {10.1093/jeb/voae067},
  volume       = {37},
  year         = {2024},
}

@article{17888,
  abstract     = {Context: Biotic resource exploitation is a critical determinant of species’ distributions. However, quantifying resource exploitation patterns through space and time can be difficult, complicating their incorporation in spatial ecology studies. Therefore, understanding the local drivers of spatial patterns of resource exploitation may contribute to better large-scale species distribution models.
Objectives: We investigated (1) how the resource exploitation patterns of two trophic interactions (plant–insect) are explained by insect behaviour, resource aggregation, and potential insect-insect interactions. We also analyzed how (2) resource patch size and (3) resource accessibility in a heterogeneous landscape affected host exploitation patterns.
Methods: We quantified nectar robbing by insects in the genus Bombus (bumblebees) and seed predation by Brachypterolus vestitus larvae (Antirrhinum beetle) on Antirrhinum majus L. (wild snapdragons) in the Pyrenees Mountains, Catalonia, Spain. We tested hypotheses about resource exploitation by integrating spatial analyses at multiple scales.
Results: Both trophic interactions were aggregated, explained by the aggregation of their resource. At some scales, nectar robbing is more aggregated than the resource. Trophic interaction abundance is proportional to resource patch size, following the ideal free distribution model. Landscape features do not explain the locations exploited. Nectar robbing and seed predation occur together more often than expected.
Conclusions: Our findings suggest that multiple biotic and ecological spatial factors may simultaneously affect resource exploitation at a local scale. These findings should be considered when developing agricultural projects, management plans and conservation policies.},
  author       = {Pocull Belles, Guillem and Baskett, Carina and Barton, Nicholas H},
  issn         = {1572-9761},
  journal      = {Landscape Ecology},
  number       = {9},
  publisher    = {Springer Nature},
  title        = {{Multiscale spatial analysis of two plant–insect interactions: Effects of landscape, resource distribution, and other insects}},
  doi          = {10.1007/s10980-024-01899-9},
  volume       = {39},
  year         = {2024},
}

@article{14850,
  abstract     = {Elaborate sexual signals are thought to have evolved and be maintained to serve as honest indicators of signaller quality. One measure of quality is health, which can be affected by parasite infection. Cnemaspis mysoriensis is a diurnal gecko that is often infested with ectoparasites in the wild, and males of this species express visual (coloured gular patches) and chemical (femoral gland secretions) traits that receivers could assess during social interactions. In this paper, we tested whether ectoparasites affect individual health, and whether signal quality is an indicator of ectoparasite levels. In wild lizards, we found that ectoparasite level was negatively correlated with body condition in both sexes. Moreover, some characteristics of both visual and chemical traits in males were strongly associated with ectoparasite levels. Specifically, males with higher ectoparasite levels had yellow gular patches with lower brightness and chroma, and chemical secretions with a lower proportion of aromatic compounds. We then determined whether ectoparasite levels in males influence female behaviour. Using sequential choice trials, wherein females were provided with either the visual or the chemical signals of wild-caught males that varied in ectoparasite level, we found that only chemical secretions evoked an elevated female response towards less parasitised males. Simultaneous choice trials in which females were exposed to the chemical secretions from males that varied in parasite level further confirmed a preference for males with lower parasites loads. Overall, we find that although health (body condition) or ectoparasite load can be honestly advertised through multiple modalities, the parasite-mediated female response is exclusively driven by chemical signals.</jats:p>},
  author       = {Pal, Arka and Joshi, Mihir and Thaker, Maria},
  issn         = {0022-0949},
  journal      = {Journal of Experimental Biology},
  keywords     = {Insect Science, Molecular Biology, Animal Science and Zoology, Aquatic Science, Physiology, Ecology, Evolution, Behavior and Systematics},
  number       = {1},
  publisher    = {The Company of Biologists},
  title        = {{Too much information? Males convey parasite levels using more signal modalities than females utilise}},
  doi          = {10.1242/jeb.246217},
  volume       = {227},
  year         = {2024},
}

@article{15358,
  abstract     = {We consider how a population of N haploid individuals responds to directional selection on standing variation, with no new variation from recombination or mutation. Individuals have trait values z1,…,zN, which are drawn from a distribution ψ; the fitness of individual i is proportional to [Formula: see text] . For illustration, we consider the Laplace and Gaussian distributions, which are parametrised only by the variance V0, and show that for large N, there is a scaling limit which depends on a single parameter NV0. When selection is weak relative to drift (NV0≪1), the variance decreases exponentially at rate 1/N, and the expected ultimate gain in log fitness (scaled by V0), is just NV0, which is the same as Robertson's (1960) prediction for a sexual population. In contrast, when selection is strong relative to drift (NV0≫1), the ultimate gain can be found by approximating the establishment of alleles by a branching process in which each allele competes independently with the population mean and the fittest allele to establish is certain to fix. Then, if the probability of survival to time t∼1/V0 of an allele with value z is P(z), with mean P¯, the winning allele is the fittest of NP¯ survivors drawn from a distribution ψP/P¯. The expected ultimate change is ∼2log(1.15NV0) for a Gaussian distribution, and ∼-12log0.36NV0-log-log0.36NV0 for a Laplace distribution. This approach also predicts the variability of the process, and its dynamics; we show that in the strong selection regime, the expected genetic variance decreases as ∼t-3 at large times. We discuss how these results may be related to selection on standing variation that is spread along a linear chromosome.},
  author       = {Barton, Nicholas H and Sachdeva, Himani},
  issn         = {1096-0325},
  journal      = {Theoretical Population Biology},
  pages        = {129--137},
  publisher    = {Elsevier},
  title        = {{Limits to selection on standing variation in an asexual population}},
  doi          = {10.1016/j.tpb.2024.04.001},
  volume       = {157},
  year         = {2024},
}

@article{15099,
  abstract     = {Speciation is a key evolutionary process that is not yet fully understood. Combining population genomic and ecological data from multiple diverging pairs of marine snails (Littorina) supports the search for speciation mechanisms. Placing pairs on a one-dimensional speciation continuum, from undifferentiated populations to species, obscured the complexity of speciation. Adding multiple axes helped to describe either speciation routes or reproductive isolation in the snails. Divergent ecological selection repeatedly generated barriers between ecotypes, but appeared less important in completing speciation while genetic incompatibilities played a key role. Chromosomal inversions contributed to genomic barriers, but with variable impact. A multidimensional (hypercube) approach supported framing of questions and identification of knowledge gaps and can be useful to understand speciation in many other systems.},
  author       = {Johannesson, Kerstin and Faria, Rui and Le Moan, Alan and Rafajlović, Marina and Westram, Anja M and Butlin, Roger K. and Stankowski, Sean},
  issn         = {1362-4555},
  journal      = {Trends in Genetics},
  number       = {4},
  pages        = {337--351},
  publisher    = {Elsevier},
  title        = {{Diverse pathways to speciation revealed by marine snails}},
  doi          = {10.1016/j.tig.2024.01.002},
  volume       = {40},
  year         = {2024},
}

@article{18949,
  abstract     = {Speciation research—the scientific field focused on understanding the origin and diversity of species—has a long and complex history. While relevant to one another, the specific goals and activities of speciation researchers are highly diverse, and scattered across a collection of different perspectives. Thus, our understanding of speciation will benefit from efforts to bridge scientific findings and the diverse people who do the work. In this paper, we outline two ways of integrating speciation research: (i) scientific integration, through the bringing together of ideas, data, and approaches; and (ii) social integration, by creating ways for a diversity of researchers to participate in the scientific process. We then discuss five challenges to integration: (i) the multidisciplinary nature of speciation research, (ii) the complex language of speciation; (iii) a bias toward certain study systems; (iv) the challenges of working across scales; and (v) inconsistent measures and reporting standards. We provide practical steps that individuals and groups can take to help overcome these challenges, and argue that integration is a team effort in which we all have a role to play.},
  author       = {Stankowski, Sean and Cutter, Asher D and Satokangas, Ina and Lerch, Brian A and Rolland, Jonathan and Smadja, Carole M and Segami Marzal, J Carolina and Cooney, Christopher R and Feulner, Philine G D and Domingos, Fabricius Maia Chaves Bicalho and North, Henry L and Yamaguchi, Ryo and Butlin, Roger K and Wolf, Jochen B W and Coughlan, Jenn and Heidbreder, Patrick and Hernández-Gutiérrez, Rebeca and Barnard-Kubow, Karen B and Peede, David and Rancilhac, Loïs and Salvador, Rodrigo Brincalepe and Thompson, Ken A and Stacy, Elizabeth A and Moyle, Leonie C and Garlovsky, Martin D and Maulana, Arif and Kantelinen, Annina and Cacho, N Ivalú and Schneemann, Hilde and Domínguez, Marisol and Dopman, Erik B and Lohse, Konrad and Rometsch, Sina J and Comeault, Aaron A and Merrill, Richard M and Scordato, Elizabeth S C and Singhal, Sonal and Pärssinen, Varpu and Lackey, Alycia C R and Kumar, Sanghamitra and Meier, Joana I and Barton, Nicholas H and Fraisse, Christelle and Ravinet, Mark and Kulmuni, Jonna},
  issn         = {2752-938X},
  journal      = {Evolutionary Journal of the Linnean Society},
  number       = {1},
  publisher    = {Oxford University Press},
  title        = {{Toward the integration of speciation research}},
  doi          = {10.1093/evolinnean/kzae001},
  volume       = {3},
  year         = {2024},
}

@article{18908,
  abstract     = {Chromosomal rearrangements can lead to the coupling of reproductive barriers, but whether and how they contribute to the completion of speciation remains unclear. Marine snails of the genus Littorina repeatedly form hybrid zones between populations segregating for multiple inversion arrangements, providing opportunities to study their barrier effects. Here, we analyzed 2 adjacent transects across hybrid zones between 2 ecotypes of Littorina fabalis (“large” and “dwarf”) adapted to different wave exposure conditions on a Swedish island. Applying whole-genome sequencing, we found 12 putative inversions on 9 of 17 chromosomes. Nine of the putative inversions reached near differential fixation between the 2 ecotypes, and all were in strong linkage disequilibrium. These inversions cover 20% of the genome and carry 93% of divergent single nucleotide polymorphisms (SNPs). Bimodal hybrid zones in both transects indicated that the 2 ecotypes of Littorina fabalis maintain their genetic and phenotypic integrity following contact. The bimodality reflects the strong coupling between inversion clines and the extension of the barrier effect across the whole genome. Demographic inference suggests that coupling arose during a period of allopatry and has been maintained for &amp;gt; 1,000 generations after secondary contact. Overall, this study shows that the coupling of multiple chromosomal inversions contributes to strong reproductive isolation. Notably, 2 of the putative inversions overlap with inverted genomic regions associated with ecotype differences in a closely related species (Littorina saxatilis), suggesting the same regions, with similar structural variants, repeatedly contribute to ecotype evolution in distinct species.},
  author       = {Le Moan, Alan and Stankowski, Sean and Rafajlović, Marina and Ortega-Martinez, Olga and Faria, Rui and Butlin, Roger K and Johannesson, Kerstin},
  issn         = {2056-3744},
  journal      = {Evolution Letters},
  number       = {4},
  pages        = {575--586},
  publisher    = {Oxford University Press},
  title        = {{Coupling of twelve putative chromosomal inversions maintains a strong barrier to gene flow between snail ecotypes}},
  doi          = {10.1093/evlett/qrae014},
  volume       = {8},
  year         = {2024},
}

@article{18491,
  abstract     = {Predicting the outcomes of adaptation is a major goal of evolutionary biology. When temporal changes in the environment mirror spatial gradients, it opens up the potential for predicting the course of adaptive evolution over time based on patterns of spatial genetic and phenotypic variation. We assessed this approach in a 30-year transplant experiment in the intertidal snail Littorina saxatilis. In 1992, snails were transplanted from a predation-dominated environment to one dominated by wave action. On the basis of spatial patterns, we predicted transitions in shell size and morphology, allele frequencies at positions throughout the genome, and chromosomal rearrangement frequencies. Observed changes closely agreed with predictions and transformation was both dramatic and rapid. Hence, adaptation can be predicted from knowledge of the phenotypic and genetic variation among populations.},
  author       = {Garcia Castillo, Diego Fernando and Barton, Nicholas H and Faria, Rui and Larsson, Jenny and Stankowski, Sean and Butlin, Roger and Johannesson, Kerstin and Westram, Anja M},
  issn         = {2375-2548},
  journal      = {Science Advances},
  number       = {41},
  publisher    = {AAAS},
  title        = {{Predicting rapid adaptation in time from adaptation in space: A 30-year field experiment in marine snails}},
  doi          = {10.1126/sciadv.adp2102},
  volume       = {10},
  year         = {2024},
}

@article{14463,
  abstract     = {Inversions are thought to play a key role in adaptation and speciation, suppressing recombination between diverging populations. Genes influencing adaptive traits cluster in inversions, and changes in inversion frequencies are associated with environmental differences. However, in many organisms, it is unclear if inversions are geographically and taxonomically widespread. The intertidal snail, Littorina saxatilis, is one such example. Strong associations between putative polymorphic inversions and phenotypic differences have been demonstrated between two ecotypes of L. saxatilis in Sweden and inferred elsewhere, but no direct evidence for inversion polymorphism currently exists across the species range. Using whole genome data from 107 snails, most inversion polymorphisms were found to be widespread across the species range. The frequencies of some inversion arrangements were significantly different among ecotypes, suggesting a parallel adaptive role. Many inversions were also polymorphic in the sister species, L. arcana, hinting at an ancient origin.},
  author       = {Reeve, James and Butlin, Roger K. and Koch, Eva L. and Stankowski, Sean and Faria, Rui},
  issn         = {1365-294X},
  journal      = {Molecular Ecology},
  number       = {24},
  publisher    = {Wiley},
  title        = {{Chromosomal inversion polymorphisms are widespread across the species ranges of rough periwinkles (Littorina saxatilis and L. arcana)}},
  doi          = {10.1111/mec.17160},
  volume       = {33},
  year         = {2024},
}

@article{18944,
  abstract     = {Understanding connectivity patterns exhibited by endangered species living in fragmented habitats is fundamental to improving management and conservation actions. Such improvements can be particularly pressing at the trailing edges of these habitats, where populations are facing the greatest challenges from climate change, and appear even more crucial if the species is commercially harvested. Seascape genetics have been increasingly used to meet these needs. In this study, we examined connectivity patterns among 32 populations of the oarweed kelp <jats:italic>Lam</jats:italic><jats:italic>inaria digitata</jats:italic> located at the species’ southern range limit. The distance (or sampling gap) between neighboring populations ranged from a few km to a few 100s of km. By genotyping 11 microsatellite markers, we aimed to (1) refine analyses of population structure; (2) test whether on-shelf islands are genetically more differentiated than mainland populations; (3) evaluate the relative importance of various abiotic conditions in shaping the genetic structure; and (4) evaluate if the relative importance of each environmental factor varied according to sampling schemes. Our analyses revealed a positive relationship between connectivity links and genetic diversity: populations with high levels of connectivity were genetically enriched while isolated populations showed signs of genetic erosion. The genetically impoverished populations corresponded to the southernmost populations as well as populations along the northern coast of Brittany (Locquirec, Saint-Malo Bay) and the northernmost population in Pas-de-Calais. By performing distance-based redundancy analysis on various sampling schemes, geographic distance appeared as the dominant factor influencing connectivity between populations separated by great distances, while hydrodynamic processes were the main factor when analyzing at a final spatial resolution.},
  author       = {Fouqueau, Louise and Reynes, L and Tempera, F and Bajjouk, T and Blanfuné, A and Chevalier, C and Laurans, M and Mauger, S and Sourisseau, M and Assis, J and Lévêque, L and Valero, M},
  issn         = {1616-1599},
  journal      = {Marine Ecology Progress Series},
  pages        = {23--42},
  publisher    = {Inter-Research Science Center},
  title        = {{Seascape genetic study on Laminaria digitata underscores the critical role of sampling schemes}},
  doi          = {10.3354/meps14640},
  volume       = {740},
  year         = {2024},
}

@misc{22870,
  abstract     = {Abstract: Chromosomal rearrangements can lead to the coupling of reproductive barriers, but whether and how they contribute to completion of speciation remains unclear. Marine snails of the genus Littorina repeatedly form hybrid zones between populations segregating for multiple inversion arrangements, providing opportunities to study their barrier effects. Here, we analysed two adjacent transects across hybrid zones between two ecotypes of Littorina fabalis (‘large’ and ‘dwarf’) adapted to different wave exposure conditions on a Swedish island. Applying whole-genome sequencing, we found 12 putative inversions on nine of 17 chromosomes. Nine of the putative inversions reached near differential fixation between the two ecotypes, and all were in strong linkage disequilibrium. These inversions cover 20% of the genome and carry 93% of divergent single nucleotide polymorphisms (SNPs). Bimodal hybrid zones in both transects indicated that the two ecotypes of Littorina fabalis maintain their genetic and phenotypic integrity following contact. The bimodality reflects the strong coupling between inversion clines and the extension of the barrier effect across the whole genome. Demographic inference suggests that coupling arose during a period of allopatry and has been maintained for >1000 generations after secondary contact. Overall, this study shows that the coupling of multiple chromosomal inversions contributes to strong reproductive isolation. Notably, two of the putative inversions overlap with inverted genomic regions associated with ecotype differences in a closely-related species (Littorina saxatilis), suggesting the same regions, with similar structural variants, repeatedly contribute to ecotype evolution in distinct species.},
  author       = {Le Moan, Alan},
  publisher    = {Repository},
  title        = {{Coupling of twelve putative chromosomal inversions maintains a strong barrier to gene flow between snail ecotypes}},
  doi          = {10.5281/zenodo.10790257},
  year         = {2024},
}

@misc{18498,
  abstract     = {Scripts and data used in the research study Predicting rapid adaptation in time from adaptation in space: a 30-year field experiment in marine snails. https://doi.org/10.1101/2023.09.27.559715},
  author       = {Garcia Castillo, Diego Fernando and Barton, Nicholas H and Faria, Rui and Larsson, Jenny and Stankowski, Sean and Butlin, Roger and Johannesson, Kerstin and Westram, Anja M},
  publisher    = {Zenodo},
  title        = {{Data and code for: Predicting rapid adaptation in time from adaptation in space: a 30-year field experiment in marine snails}},
  doi          = {10.5281/ZENODO.12159343},
  year         = {2024},
}

@phdthesis{14711,
  abstract     = {In nature, different species find their niche in a range of environments, each with its unique characteristics. While some thrive in uniform (homogeneous) landscapes where environmental conditions stay relatively consistent across space, others traverse the complexities of spatially heterogeneous terrains. Comprehending how species are distributed and how they interact within these landscapes holds the key to gaining insights into their evolutionary dynamics while also informing conservation and management strategies.

For species inhabiting heterogeneous landscapes, when the rate of dispersal is low compared to spatial fluctuations in selection pressure, localized adaptations may emerge. Such adaptation in response to varying selection strengths plays an important role in the persistence of populations in our rapidly changing world. Hence, species in nature are continuously in a struggle to adapt to local environmental conditions, to ensure their continued survival. Natural populations can often adapt in time scales short enough for evolutionary changes to influence ecological dynamics and vice versa, thereby creating a feedback between evolution and demography. The analysis of this feedback and the relative contributions of gene flow, demography, drift, and natural selection to genetic variation and differentiation has remained a recurring theme in evolutionary biology. Nevertheless, the effective role of these forces in maintaining variation and shaping patterns of diversity is not fully understood. Even in homogeneous environments devoid of local adaptations, such understanding remains elusive. Understanding this feedback is crucial, for example in determining the conditions under which extinction risk can be mitigated in peripheral populations subject to deleterious mutation accumulation at the edges of species’ ranges
as well as in highly fragmented populations.

In this thesis we explore both uniform and spatially heterogeneous metapopulations, investigating and providing theoretical insights into the dynamics of local adaptation in the latter and examining the dynamics of load and extinction as well as the impact of joint ecological and evolutionary (eco-evolutionary) dynamics in the former. The thesis is divided into 5 chapters.

Chapter 1 provides a general introduction into the subject matter, clarifying concepts and ideas used throughout the thesis. In chapter 2, we explore how fast a species distributed across a heterogeneous landscape adapts to changing conditions marked by alterations in carrying capacity, selection pressure, and migration rate.

In chapter 3, we investigate how migration selection and drift influences adaptation and the maintenance of variation in a metapopulation with three habitats, an extension of previous models of adaptation in two habitats. We further develop analytical approximations for the critical threshold required for polymorphism to persist.

The focus of chapter 4 of the thesis is on understanding the interplay between ecology and evolution as coupled processes. We investigate how eco-evolutionary feedback between migration, selection, drift, and demography influences eco-evolutionary outcomes in marginal populations subject to deleterious mutation accumulation. Using simulations as well as theoretical approximations of the coupled dynamics of population size and allele frequency, we analyze how gene flow from a large mainland source influences genetic load and population size on an island (i.e., in a marginal population) under genetically realistic assumptions. Analyses of this sort are important because small isolated populations, are repeatedly affected by complex interactions between ecological and evolutionary processes, which can lead to their death. Understanding these interactions can therefore provide an insight into the conditions under which extinction risk can be mitigated in peripheral populations thus, contributing to conservation and restoration efforts.

Chapter 5 extends the analysis in chapter 4 to consider the dynamics of load (due to deleterious mutation accumulation) and extinction risk in a metapopulation. We explore the role of gene flow, selection, and dominance on load and extinction risk and further pinpoint critical thresholds required for metapopulation persistence.

Overall this research contributes to our understanding of ecological and evolutionary mechanisms that shape species’ persistence in fragmented landscapes, a crucial foundation for successful conservation efforts and biodiversity management.},
  author       = {Olusanya, Oluwafunmilola O},
  issn         = {2663-337X},
  pages        = {183},
  publisher    = {Institute of Science and Technology Austria},
  title        = {{Local adaptation, genetic load and extinction in metapopulations}},
  doi          = {10.15479/at:ista:14711},
  year         = {2024},
}

@article{17142,
  abstract     = {Despite the diverse genetic origins of autism spectrum disorders (ASDs), affected individuals share strikingly similar and correlated behavioural traits that include perceptual and sensory processing challenges. Notably, the severity of these sensory symptoms is often predictive of the expression of other autistic traits. However, the origin of these perceptual deficits remains largely elusive. Here, we show a recurrent impairment in visual threat perception that is similarly impaired in 3 independent mouse models of ASD with different molecular aetiologies. Interestingly, this deficit is associated with reduced avoidance of threatening environments—a nonperceptual trait. Focusing on a common cause of ASDs, the Setd5 gene mutation, we define the molecular mechanism. We show that the perceptual impairment is caused by a potassium channel (Kv1)-mediated hypoexcitability in a subcortical node essential for the initiation of escape responses, the dorsal periaqueductal grey (dPAG). Targeted pharmacological Kv1 blockade rescued both perceptual and place avoidance deficits, causally linking seemingly unrelated trait deficits to the dPAG. Furthermore, we show that different molecular mechanisms converge on similar behavioural phenotypes by demonstrating that the autism models Cul3 and Ptchd1, despite having similar behavioural phenotypes, differ in their functional and molecular alteration. Our findings reveal a link between rapid perception controlled by subcortical pathways and appropriate learned interactions with the environment and define a nondevelopmental source of such deficits in ASD.},
  author       = {Burnett, Laura and Koppensteiner, Peter and Symonova, Olga and Masson, Tomas and Vega Zuniga, Tomas A and Contreras, Ximena and Rülicke, Thomas and Shigemoto, Ryuichi and Novarino, Gaia and Jösch, Maximilian A},
  issn         = {1545-7885},
  journal      = {PLoS Biology},
  publisher    = {Public Library of Science},
  title        = {{Shared behavioural impairments in visual perception and place avoidance across different autism models are driven by periaqueductal grey hypoexcitability in Setd5 haploinsufficient mice}},
  doi          = {10.1371/journal.pbio.3002668},
  volume       = {22},
  year         = {2024},
}

@article{18168,
  abstract     = {Despite the considerable interest in the recombinant production of synthetic spider silk fibers that possess mechanical properties similar to those of native spider silks, such as the cost-effectiveness, tunability, and scalability realization, is still lacking. To address this long-standing challenge, we have constructed an artificial spider silk gene using Golden Gate assembly for the recombinant bacterial production of dragline-mimicking silk, incorporating all the essential components: the N-terminal domain, a 33-residue-long major-ampullate-spidroin-inspired segment repeated 16 times, and the C-terminal domain (N16C). This designed silk-like protein was successfully expressed in Escherichia coli, purified, and cast into films from formic acid. We produced uniformly 13C–15N-labeled N16C films and employed solid-state magic-angle spinning nuclear magnetic resonance (NMR) for characterization. Thus, we could demonstrate that our bioengineered silk-like protein self-assembles into a film where, when hydrated, the solvent-exposed layer of the rigid, β-nanocrystalline polyalanine core undergoes a transition to an α-helical structure, gaining mobility to the extent that it fully dissolves in water and transforms into a highly dynamic random coil. This hydration-induced behavior induces chain dynamics in the glycine-rich amorphous soft segments on the microsecond time scale, contributing to the elasticity of the solid material. Our findings not only reveal the presence of structurally and dynamically distinct segments within the film’s superstructure but also highlight the complexity of the self-organization responsible for the exceptional mechanical properties observed in proteins that mimic dragline silk.},
  author       = {Wu, Dongqing and Koscic, Anamaria and Schneider, Sonja and Dubini, Romeo C. A. and Rodriguez Camargo, Diana C. and Schneider, Sabine and Rovo, Petra},
  issn         = {1526-4602},
  journal      = {Biomacromolecules},
  number       = {3},
  pages        = {1759--1774},
  publisher    = {American Chemical Society},
  title        = {{Unveiling the dynamic self-assembly of a recombinant dragline-silk-mimicking protein}},
  doi          = {10.1021/acs.biomac.3c01239},
  volume       = {25},
  year         = {2024},
}

@phdthesis{18135,
  abstract     = {This thesis consists of two separate parts. In the first part we consider a dilute Fermi gas interacting through a repulsive interaction in dimensions $d=1,2,3$. Our focus is mostly on the physically most relevant dimension $d=3$ 
and the setting of a spin-polarized (equivalently spinless) gas, where the Pauli exclusion principle plays a key role. We show that, at zero temperature, the ground state energy density of the interacting spin-polarized gas differs (to leading order) from that of the free (i.e. non-interacting) gas by a term of order $a_p^d\rho^{2+2/d}$  with $a_p$ the $p$-wave scattering length of the repulsive interaction and $\rho$ the density. Further, we extend this to positive temperature and show that the pressure of an interacting spin-polarized gas differs from that of the free gas by a now temperature dependent term, again of order $a_p^d\rho^{2+2/d}$. Lastly, we consider the setting of a spin-$\frac{1}{2}$ Fermi gas in $d=3$ dimensions and show that here, as an upper bound, the ground state energy density differs from that of the free system by a term of order $a_s \rho^2$ with an error smaller than $a_s \rho^2 (a_s\rho^{1/3})^{1-\eps}$ for any $\eps > 0$, where $a_s$ is the $s$-wave scattering length of the repulsive interaction. 

These asymptotic formulas complement the similar formulas in the literature for the dilute Bose and spin-$\frac{1}{2}$ Fermi gas, where the ground state energies or pressures differ from that of the corresponding free systems by a term of order $a_s \rho^2$ in dimension $d=3$. In the spin-polarized setting, the corrections, of order $a_p^3\rho^{8/3}$ in dimension $d=3$, are thus much smaller and requires a more delicate analysis.

In the second part of the thesis we consider the Bardeen--Cooper--Schrieffer (BCS) theory of superconductivity and in particular its associated critical temperature and energy gap. We prove that the ratio of the zero-temperature energy gap and critical temperature $\Xi(T=0)/T_c$ approaches a universal constant $\pi e^{-\gamma}\approx 1.76$ in both the limit of high density in dimension $d=3$ and in the limit of weak coupling in dimensions $d=1,2$. This complements the proofs in the literature of this universal behaviour in the limit of weak coupling or low density in dimension $d=3$. Secondly, we prove that the ratio of the energy gap at positive temperature and critical temperature $\Xi(T)/T_c$ approaches a universal function of the relative temperature $T/T_c$ in the limit of weak coupling in dimensions $d=1,2,3$.},
  author       = {Lauritsen, Asbjørn Bækgaard},
  isbn         = {978-3-99078-042-8},
  issn         = {2663-337X},
  pages        = {353},
  publisher    = {Institute of Science and Technology Austria},
  title        = {{Energies of dilute Fermi gases and universalities in BCS theory}},
  doi          = {10.15479/at:ista:18135},
  year         = {2024},
}

@article{15164,
  abstract     = {Primary implant stability, which refers to the stability of the implant during the initial healing period is a crucial factor in determining the long-term success of the implant and lays the foundation for secondary implant stability achieved through osseointegration. Factors affecting primary stability include implant design, surgical technique, and patient-specific factors like bone quality and morphology. In vivo, the cyclic nature of anatomical loading puts osteosynthesis locking screws under dynamic loads, which can lead to the formation of micro cracks and defects that slowly degrade the mechanical connection between the bone and screw, thus compromising the initial stability and secondary stability of the implant. Monotonic quasi-static loading used for testing the holding capacity of implanted screws is not well suited to capture this behavior since it cannot capture the progressive deterioration of peri‑implant bone at small displacements. In order to address this issue, this study aims to determine a critical point of loss of primary implant stability in osteosynthesis locking screws under cyclic overloading by investigating the evolution of damage, dissipated energy, and permanent deformation. A custom-made test setup was used to test implanted 2.5 mm locking screws under cyclic overloading test. For each loading cycle, maximum forces and displacement were recorded as well as initial and final cycle displacements and used to calculate damage and energy dissipation evolution. The results of this study demonstrate that for axial, shear, and mixed loading significant damage and energy dissipation can be observed at approximately 20 % of the failure force. Additionally, at this load level, permanent deformations on the screw-bone interface were found to be in the range of 50 to 150 mm which promotes osseointegration and secondary implant stability. This research can assist surgeons in making informed preoperative decisions by providing a better understanding of the critical point of loss of primary implant stability, thus improving the long-term success of the implant and overall patient satisfaction.},
  author       = {Silva-Henao, Juan D. and Schober, Sophie and Pahr, Dieter H. and Reisinger, Andreas G.},
  issn         = {1873-4030},
  journal      = {Medical Engineering and Physics},
  publisher    = {Elsevier},
  title        = {{Critical loss of primary implant stability in osteosynthesis locking screws under cyclic overloading}},
  doi          = {10.1016/j.medengphy.2024.104143},
  volume       = {126},
  year         = {2024},
}