Program.

While much of the core machinery of sexual reproduction is ancient and broadly conserved across eukaryotes, many molecules that mediate mating and fertilization are among the fastest evolving in nearly every genome examined. Sex pheromones, seminal fluid proteins, and sperm-egg recognition proteins commonly bear signatures of positive selection, with sexual selection and sexual conflict driving coevolutionary "arms races" between interacting molecules that may contribute to reproductive isolation and speciation. The same rapid divergence has long made these systems difficult to study, since many reproductive proteins are lineage-specific, sparsely annotated, and unrecognizable as homologs beyond close relatives. Recent technical advances have begun to change this: densely sampled genomes allow the origins of reproductive gene families to be traced across clades, proteomic methods identify the molecules present in gametes and reproductive secretions directly, and structure prediction can recover distant homology and model interactions between male and female proteins. Together these approaches are yielding more thorough descriptions of reproductive systems’ evolution in model and non-model organisms alike, and are beginning to reveal general principles of how sexual selection shapes molecular evolution. This symposium will bring together researchers working across eukaryotes and prokaryotes on topics including the origins of reproductive genes through duplication, co-option, and de novo emergence; coevolution between interacting male and female molecules; the structural basis of species-specific gamete recognition; and the contribution of reproductive divergence to speciation. We particularly welcome work that pairs evolutionary inference with functional experiments in both model and non-model systems.

Admixture between diverged lineages is documented across nearly every branch of the tree of life, and a growing body of work shows this contact can be a direct source of adaptive alleles, accelerating local adaptation, evolutionary rescue, and trait innovation. From archaic-derived variation shaping immune and hypoxia-response traits in humans, to adaptively introgressed alleles in canids, cetaceans, fish, and plants, cross-lineage gene flow is increasingly recognized as a recurring route to rapid adaptation. Yet the methods for detecting it, and the theory explaining when and why it succeeds, remain fragmented across subfields.

Our symposium will bring together researchers using local ancestry inference, selection scans, ancestral recombination graphs, and other admixture-aware methods to detect and characterize adaptively introgressed variation across systems. We welcome contributions studying any organism, including non-model and understudied taxa, where adaptive admixture remains far less characterized. Topics will include: (i) methodological advances in local ancestry inference and selection scans, including in low-coverage, non-reference genomes, and pangenomes; (ii) case studies across wildlife, domesticates, humans, and non-model taxa; (iii) theory and simulation on when adaptive gene flow is favoured in populations departing from standard assumptions; and (iv) admixture's role in evolutionary adaptation under rapid environmental change. Our goal is to unite population genetics with evolutionary theory around one question: when and how does cross-lineage gene flow become adaptive, and does the answer differ across the tree of life?

Genomic data, ancient and modern, have transformed how we infer past demography, admixture and adaptation in human populations. Yet genetic signals alone rarely explain how and why populations moved, mixed or changed. It is becoming increasingly clear that evolutionary inferences benefit from integrating human genomes with pathogen and commensal genomes, as well as archaeological, morphological, isotopic, linguistic, paleoenvironmental and historical sources, and community-based knowledge. Bringing together diverse expertise and perspectives raises shared challenges: reconciling evidence across temporal and spatial scales, integrating heterogeneous and incomplete records, and building participatory frameworks.

This symposium will explore the reconstruction of population history in the Americas through complementary approaches, with particular interest in multidisciplinary or methodological study designs that move beyond overly genomics-centred depictions of human history and evolution. We welcome works on demographic inference and admixture from ancient and modern human genomes; pathogen and microbiome genomics informing reconstructions of human movement, contact and lifeways; adaptation, including immune and diet-related variation, and host-microbe coevolution; methods for combining sparse, heterogeneous and degraded records; and projects developed with descendant and local communities, with attention to how such collaborations shape research questions, interpretation, and knowledge production.

The Americas serve as a connecting case study, while contributions from other regions are encouraged where they offer comparative perspectives or new insights into population dynamics on the continent. Our aim is to compare approaches across disciplines, evidence types and regions to build a more integrated understanding of population history in the Americas, while identifying the methodological and ethical challenges involved.

Evolutionary innovations in complex traits such as morphological structures, reproductive modes, physiological adaptations, and developmental strategies, have shaped patterns of diversification, speciation, and extinction across the tree of life. Fundamental questions remain about how these innovations arise; to what extent they evolve through incremental changes, major evolutionary steps, or co-ordinated responses, and if there are shared principles to their molecular features of origin and maintenance. Only by exploration and comparison across a range of case studies can this be determined. Recent methodological advances in genetic, regulatory, and developmental processes underlying evolutionary innovations are transforming our understanding of the molecular mechanisms underlying major innovations in evolution, including on non-model species and wildlife. New tools are enabling research on a wider array of organisms and contexts than ever before. This symposium will showcase emerging research on the molecular evolution of novel trait innovations and their evolutionary impacts, across methodologies and study systems. We are particularly interested in studies that integrate molecular and evolutionary perspectives with ecological or life-history context, to understand how evolutionary potential and natural selection contribute to adaptation and biodiversity. By bringing together researchers working across diverse organisms, subdisciplines, and methodological approaches, this symposium aims to highlight new discoveries, foster interdisciplinary dialogue, and identify future directions in the study of evolutionary innovation.

Molecular and evolutionary biology has become a resource-intensive science: generating, storing, and analyzing data now demands infrastructure and funding concentrated overwhelmingly in the Global North. For researchers, communities, and institutions in the Global South, this asymmetry too often reproduces old patterns of dependency, turning them into data producers rather than agenda-setters, sites of extraction rather than partners in interpretation. This symposium is thought as a place to highlight how scientific practice in the Global South can be built on different terms: how to maintain scientific control, methodological integrity, and intellectual autonomy in molecular and evolutionary biology while still engaging in a deeply unequal global research system.

We invite researchers from all fields to present their scientific work with a special focus on the structural asymmetries in infrastructure, expertise, and agenda-setting that shape their research. We expect discussion on practical, economical, and ethical perspectives that would enable priority-setting, data governance, and interpretation to be genuinely shared rather than concentrated in institutions and funding agencies in the Global North.

Beyond diagnosing the problem, this symposium makes the case for scientific freedom, community-led research networks, and broader societal engagement, calling on scientists to embrace their role as active citizens working toward a more equitable and resilient science.

Relatedness is one of the oldest ideas in genetics, and it plays many roles: it can be a confounder in association studies that must be accounted for; it is a parameter guiding decisions in breeding and conservation studies; it is an object of study in population genomics, where it informs historical and evolutionary reconstructions. Relatedness can be measured and represented in many ways, including pedigrees, identity-by-descent (IBD) segments, genetic relatedness matrices, and ancestral recombination graphs (ARGs).

This symposium brings together researchers who infer relatedness and those who use it, across human and non-human populations. The timing is favorable: genealogy inference has become tractable at biobank scale, dense genomic data now make relatedness estimable in non-model systems and ancient DNA, and recent theory is beginning to connect different representations. A central question is how pedigrees, IBD segments, relatedness matrices, ARGs, and social relationships agree, differ, and complement one another. We welcome work on inference, from pedigree reconstruction and IBD detection to genealogy estimation, including machine learning and simulation-based methods, as well as applications where relatedness is the signal, across demography, selection, trait variation, and studies linking genetic and social relatedness. Because these quantities are often inferred rather than observed, the symposium will also consider when uncertainty affects downstream conclusions.

By treating relatedness as a shared problem across several traditions, the symposium connects communities that rarely share a room: quantitative geneticists, population geneticists, method developers, and empiricists working across the tree of life.

The accelerating loss of biodiversity, habitat fragmentation, climate change, emerging diseases, and anthropogenic pressures are increasingly challenging traditional approaches to biodiversity conservation. In this context, conservation genomics has emerged as a powerful interdisciplinary field that provides high-resolution information on genetic diversity, population structure, evolutionary history, demographic processes, adaptive potential, and the genetic consequences of environmental change. Thus, this proposal promotes discussion of methods and approaches for conserving non-model species worldwide, including endangered species, as well as species with wide distributions about which little is known regarding their conservation status and demographic histories. Thus, the symposium was expected to discuss studies about population genetics, phylogeographic histories, and consequences for wildlife conservation in non-model vertebrate and invertebrate organisms. Thus, we have the objective of discussing recent advances in population genomics; exploring genomic approaches for assessing genetic diversity and population structure; examining the role of genomics in identifying inbreeding, genetic erosion, and loss of adaptive potential; discussing genomic approaches for understanding local adaptation and evolutionary resilience; presenting applications of genomic monitoring in threatened and fragmented populations; exploring the use of environmental DNA and other molecular approaches for biodiversity monitoring; and discussing bioinformatic challenges associated with conservation genomic datasets. In particular, we seek to incentivize researchers in the Southern Hemisphere to contribute to this discussion, highlighting the limitations of genomic data used in low-resource settings and alternatives to overcome them.

Evolution affects not only all aspects of biology but also everyone’s daily lives. However, a large part of the general public remains unaware of the of evolution’s impact, even in critical areas such as public health and the environment. Moreover, students in the life sciences, even those studying biology, do not fully grasp the central role of evolution in their field or its applications to societal challenges. In a world increasingly disrupted by anthropogenic pressures and the emergence of new communicable diseases, it is crucial for all citizens to better understand the impact of evolution. Only such understanding can lead to supporting measures against epidemics, drug and pesticide resistance, climate change and habitat degradation (caused by pollution, urbanization, habitat fragmentation), as well as promote food security and biodiversity conservation (Brandt et al. 2022). It is equally crucial that life science students understand how the principles of evolution influence all the living world, from the molecular level to ecosystems, so they are prepared to apply these concepts in addressing societal problems, not only in the realm of life sciences, but also in policy and governance (Pessoa et al. 2024). This symposium will present diverse approaches – ranging from science outreach and citizen science, to teaching at different levels (from elementary school to university) –, to enhance evolution literacy.

Brandt et al (2022). Promoting scientific literacy in evolution through citizen science. https://doi.org/10.1098/rspb.2022.1077

Pessoa et al (2024). Evolutionary literacy as a catalyst for sustainable futures: connecting biological evolution education and education for sustainability. https://doi.org/10.1186/s12052-024-00213-0

Polyploidy is a ubiquitous and powerful form in life evolution. Initiated in meiotic and/or mitotic errors, polyploids face challenges ranging from the cellular to the population level. Redundant genomes pose prominent genomic stress and imbalance between different compartments. The often-faltered inter-ploidy hybridization constitutes reproductive obstacles for nascent polyploids. Overlapping ecological niche with the parental species confines the suitable space for descendant polyploids to grow and develop. Yet, accompanying the high evolutionary risk is the high gain once it is established. The additional genome copies increase the genomic complexity and expand the genetic repertoire with neofunctionalized and subfunctionalized paralogues. The rewiring of multiplicated gene regulatory networks can be adaptively tuned to meet different ecological needs. The rediploidization process guarantees the restoring of normal bivalent pairing and fractionates with chromosome rearrangements that generate structural variations. Nonetheless, the wax and wane of polyploids depend on the biotic and abiotic contexts. A particular polyploid lineage may thrive under one environmental condition but falter under another. To fully understand the underlying mechanism of polyploid biology and evolution, we need a combination of extensive empirical case studies and theoretic studies of polyploid formation, adaptation, and establishment. In this symposium, we aim to collate a diverse range of talks and posters that cover different aspects of polyploid biology and evolution focusing on different lineages. The insights garnered from this collection can advance our understanding of how life evolves to adapt a changing world and how the current changing world is reshaping the life evolution on Earth.

The 2027 SMBE IDEA Symposium celebrates the ongoing commitment of SMBE to fostering an inclusive, equitable, and diverse scientific community. This symposium underscores our mission to confront systemic inequities, including racism, ableism, sexism, colonialism, and other forms of exclusion, while empowering underrepresented and minoritized groups in the fields of molecular biology and evolution. The symposium will feature an update on the IDEA committee’s activities over the past year and an invited speaker with expertise in the field of DEI. We will also be hearing from previous IDEA grant awardees. We invite abstract submissions that highlight community-driven efforts to broaden participation, dismantle barriers, create a more welcoming environment for scientists of all backgrounds, career stages, and geographic locations, and/or advance inclusion, diversity, equity, and accessibility in molecular biology and evolution and related fields. Education-related works are also welcome, as they play an important role in shaping the future of our scientific community. The symposium will close with a discussion with speakers, symposium organizers, and attendants. Through these discussions, we aim to share innovative practices, celebrate achievements, listen to the needs of our membership, and inspire actionable change in our scientific community and beyond.

The recent boom in the field of artificial intelligence (AI), including deep learning, transformers, and neural networks, has created new opportunities in how we study evolution with microbial genomes. Bacterial and virus genomes encode deep information about historical evolutionary forces: in gene synteny and structure, in genomic signatures of selection, and in protein coevolutionary coupling. Hundreds of thousands of sequenced microbial genomes and metagenomes are the source of much of the information that underlies genome and protein language models. Further, microbial evolution often occurs on observable and measurable timescales, so model predictions of evolution can be directly tested in microbial systems. Therefore, the microbial world presents a unique opportunity for the application of genomic models to evolutionary biology.

This symposium aims to bring together researchers working on diverse applications of AI models in understanding and predicting both bacterial and viral evolution from genomic information. Speakers will address questions such as: How can models measure and learn from the impact of evolution on the genome? How can we use and test models to predict future evolution? How do we rigorously validate the performance of complex models over simpler models? Together, this symposium creates a forum for dialogue across evolutionary biologists and biological AI experts studying bacteria and viruses on how new modeling approaches can learn the rules of evolution from genomes.

Classical phylogenetics first used morphology, and then nucleotide or amino acid sequences to reconstruct evolutionary relationships. Protein structures also possess desirable phylogenetic properties, particularly in their high conservation and retention of deep evolutionary signal. Historical use of protein structural phylogenetics has been limited by a relative lack of data and methods, but this is starting to change. The advent of protein structure prediction methods like AlphaFold enables mass structure determination across culturable and unculturable taxa. The development of protein structural alphabets has provided significant momentum to structural phylogenetics, as these alphabets can facilitate usage of the robust probabilistic methods used in classical phylogenetics. Structural phylogenetics has shown promise in identifying homologies and gene families otherwise missed by classical phylogenetics, but further methodological and technical development is needed.

This symposium will provide a timely forum for researchers working across structural, evolutionary and computational biology to discuss this emerging third era of phylogenetics. We invite talks that demonstrate novel methodological advances and applications within protein structural phylogenetics. Specific topics can include, but are not limited to; 1) development of structural alphabets using AI-based approaches, 2) applications that identify deep homologies and evolutionary relationships missed by classical phylogenetics, 3) improvements for probabilistic structural phylogenetics of deep-time evolution. These talks will highlight both the state-of-the-art of the field, and future directions and priorities. As a whole this symposium will synthesize knowledge across distinct but interconnected disciplines, and help the developing field of protein structural phylogenetics to mature.

The Earth BioGenome Project (EBP) launched in 2018 as a global initiative to collaboratively sequence high-quality reference genomes for all named eukaryotic species on Earth. These chromosome-scale genomes are driving a sea change in our understanding of major evolutionary processes, including speciation and adaptation, as well as shedding light on species evolutionary relationships and the multi-dimensional landscape of genome evolution. The EBP promotes open access to genome data to make comparative genomics more accessible to researchers globally, and to create an enduring resource that will continue to generate new discoveries as the genomes are reused, reanalysed and integrated with future datasets.

With reference genomes sequenced for nearly 10,000 species, EBP is rapidly approaching the completion of Phase I. This symposium is an opportunity to reflect on how EBP resources are transforming our understanding of biodiversity and evolution, and enabling genomic patterns and evolutionary processes to be studied at previously infeasible scales. This symposium will bring together researchers working with EBP genomes across Earth’s biodiversity. We invite researchers from all scientific backgrounds to present their work, especially those studying biodiversity genomics at scale, uncovering novel or previously inaccessible aspects of genome or species evolution in understudied lineages, or involving the development of innovative approaches for analysing increasingly large and complex datasets. This symposium will also showcase research made possible by advances in both sequencing technologies and analytical methods. Our primary aim will be to share ideas, promote collaboration, and inspire new research using EBP resources.

Evolvability is a wide-ranging and contested concept within evolutionary theory. It is the capacity of a lineage to generate heritable variation which contributes to evolutionary change - typically considered in terms of adaptive variation. Classical population genetics treats the origin of variation as a black box, and whether this capacity could itself evolve has been disputed. This symposium addresses three related questions. The first is what evolvability is made of: the mutational processes, regulatory architectures, protein biophysics, developmental systems, and genotype–phenotype maps that determine what variation arises and whether and how it is expressed. As at least some of these foundations seem to differ across lineages, this raises our second question: how and in what contexts does evolvability change? The third question is whether some of the foundations of evolvability have been a target of selection. This becomes tractable once the molecular bases are known: one can ask whether there is more evolvability than null models grounded in the biological origins and constraints of those bases would predict. We welcome contributions on any of these fronts, using empirical or theoretical approaches, including conceptual analyses that engage with recent data . Our aim is to sharpen these questions by grounding evolvability in molecular mechanisms that can be measured and compared across taxa.

Sex is one of the most fundamental biological traits, yet the mechanisms that determine it are remarkably diverse across the Tree of Life. Recent advances in genomics, comparative biology, and evolutionary theory have revealed that sex-determining pathways are far more dynamic and evolutionarily labile than previously appreciated. This symposium will bring together researchers studying sex determination and sex chromosome evolution across a broad range of taxa, including animals, plants, and other eukaryotes. By integrating perspectives from molecular evolution, genomics, developmental biology, and evolutionary ecology, the symposium will highlight both shared principles and lineage-specific innovations underlying the origin, maintenance, and turnover of sex-determining systems.

Topics will include the emergence of novel sex chromosomes, the evolution of master sex-determining genes, transitions between genetic and environmental sex determination, dosage compensation mechanisms, chromosome degeneration and turnover, and the evolutionary consequences of diverse reproductive systems. Particular emphasis will be placed on how comparative and evolutionary approaches are reshaping our understanding of one of biology’s most complex and rapidly evolving traits. By showcasing discoveries from diverse organisms and methodological frameworks, this symposium will provide a unique opportunity to identify common evolutionary patterns, foster interdisciplinary collaborations, and stimulate new research directions in the study of sex determination and sex chromosome evolution across the Tree of Life.

Atypical chromosomes were first described 120 years ago in an insect and come in a myriad of names such as dispensable, outlier, accessory, supernumerary, mini or B chromosomes. Advances in sequencing technologies have now revealed their complete gene content and architecture across more than 2000 species, spanning mammals, insects, land plants, fungi, and understudied protistan lineages. Once dismissed as rare genetic oddities, these chromosomes are now recognized as widespread, dynamic genomic elements that can drive rapid evolutionary change through non-Mendelian inheritance. This symposium will explore the diversity, function, and evolutionary processes underlying the origin and maintenance of atypical chromosomes, historically identified by unusual karyotypes but now characterized at the molecular level based on conservation, gene/repeat contents and epigenetic markers. Understanding their evolution is crucial for deciphering the molecular mechanisms of meiotic drive, as well as for elucidating the roles of atypical chromosomes in adaptation and the emergence of novel genes and phenotypes. We welcome studies employing comparative and population genomics, epigenomics, experimental evolution, molecular biology and cytology approaches to shed light on the diversity, fitness effects, and evolutionary history of atypical chromosomes. We also encourage integrative studies investigating the molecular mechanisms driving the evolutionary dynamics of these chromosomes, which are often associated with meiotic drive, segregation distortion, and other forms of transmission bias.

Evolutionary change is often interpreted through an additive lens, in which the effects of genetic variants can be considered independently. Yet adaptation occurs in complex genetic and phenotypic backgrounds, where epistasis and pleiotropy can profoundly alter the effects of mutations, the accessibility of adaptive trajectories, and the predictability of evolution. These non-additive effects may generate constraints and trade-offs, but can also create opportunities for evolutionary innovation and facilitate adaptation.

This symposium will bring together theoretical, computational and experimental approaches to ask a central question: how do interactions among genetic effects shape the adaptive responses of evolving populations? We will examine how epistasis and pleiotropy influence the tempo and repeatability of adaptation, the emergence of evolutionary constraints, and the relationship between genotype, phenotype and fitness. Particular emphasis will be placed on connecting molecular mechanisms to population-level evolutionary dynamics.

The symposium will deliberately span sexual and asexual systems, including experimental evolution in microbes and multicellular organisms, as well as natural populations. Contributions may address questions ranging from mutation-by-mutation interactions and fitness landscapes to the genetic architecture and adaptation of quantitative traits, linkage and recombination, and pleiotropic trade-offs. By combining theory with experiments and diverse biological systems, the symposium will provide a forum for identifying general principles while highlighting where the consequences of non-additivity depend on population structure, reproductive mode, genetic architecture or environment.

Plant domestication is an evolutionary process whereby plants evolve under novel anthropogenic environments and human cultivation. Domesticated species supported the development of agriculture, ultimately reshaping not only human societies but also entire ecosystems. For more than a century, domestication has been a major topic of interest for evolutionary biologists, who aim to understand the nature of adaptation during domestication, the genetic basis of traits underlying crop phenotypes, patterns of local adaptation to novel climates and cultural contexts, and the demographic histories of domesticated species.

The consequences of agriculture on human populations has also long been of interest, with human evolutionary geneticists studying the effects of agriculture on human demographic trajectories and searching for signatures of selection associated with the origins and spread of agriculture. More recently, aDNA has permitted researchers to track the effects of the transition to agriculture over time.

Domestication is perhaps best understood as a coevolutionary process, where plant and people partners evolve in response to one another. We invite both researchers studying plant domestication as well as those studying human evolutionary responses to agriculture. By uniting these two fields, we aim to advance the understanding of the genetic nature of crop-human interactions and their consequences on the evolution of both plants and people.

Research on symbiotic relationships between multicellular organisms, ranging from pathogenic to mutualistic interactions, has made fundamental contributions to our understanding of biology and evolution. However, advances in microscopy, genome sequencing, and other molecular approaches are now enabling researchers to observe, characterise, and disentangle an expanding world of microbial eukaryotic symbioses.

Recent studies have begun to reveal a largely unexplored network of interactions among unicellular eukaryotes, challenging our understanding of how symbioses evolve and function at the microscopic scale. In this symposium, presentations will showcase how cutting-edge approaches are illuminating this hidden diversity of eukaryotic symbioses. We will explore examples of interactions occurring at the micron scale and consider their implications for broader questions in molecular biology and evolution.

The talks and posters will take the audience on a journey through the diversity of known microbial eukaryotic symbioses, the ecological and cellular contexts in which they occur, and the benefits, costs, and evolutionary consequences they confer on their partners and surrounding communities. Together, these contributions will highlight how studying eukaryotic symbionts can reveal new perspectives on the evolution of complex interactions and the molecular mechanisms that underpin them.

For two decades, reference assemblies have lacked the most repetitive and structurally complex parts of genomes. Centromeres, telomeres and subtelomeres, satellite arrays, acrocentric short arms carrying ribosomal DNA, multi-copy gene families, and sequences forming non-canonical (non-B) DNA structures were collapsed, misassembled, or left as gaps. Long-read sequencing and telomere-to-telomere (T2T) assemblies have now resolved these regions in humans, great apes, and a rapidly growing list of other species, from plants and insects to fish, birds, and mammals. For the first time, we can study how these regions evolve at base-pair resolution and across the tree of life.

This symposium will bring together researchers asking evolutionary questions about the newly accessible genome. How do centromeric and other satellite arrays expand, contract, and turn over between species and within populations? What mutational processes, such as unequal crossover, gene conversion, and replication errors at non-B DNA, shape these regions? How do multi-copy genes and segmental duplications arise and diversify, and what are their roles in adaptation and disease? How do these regions contribute to chromosome rearrangements, meiotic drive, hybrid incompatibility, and speciation? And which new methods are needed to align, genotype, and model sequences that defy standard tools?

We welcome studies from any taxon, using comparative genomics, population genetics, pangenomics, epigenomics, experimental evolution, and computational method development. By connecting researchers working on different organisms and regions, the symposium aims to define the evolutionary principles of the most dynamic parts of genomes.

Protein abundances span orders of magnitude within and across organisms, yet why each protein is expressed at its particular level remains a fundamental evolutionary question. Protein abundance is shaped by multiple, sometimes competing forces: the functional benefits of gene products, the energetic and physiological costs of their production, constraints on cellular resources and proteome allocation, gene dosage and regulatory architecture, and the deleterious consequences of inappropriate expression. Together, these forces determine how gene expression evolves.

This symposium will bring together diverse perspectives on the evolution of protein abundance, spanning molecular evolution, quantitative cell physiology, gene regulation, proteome allocation, development, and theoretical modeling. We will explore how changes in gene dosage and regulatory programs alter phenotypes, how cells allocate finite resources among proteins, how expression costs and toxicity constrain protein abundance, and how mutation and natural selection navigate these constraints. By connecting studies across organisms and biological scales, from bacteria and yeast to multicellular systems, the symposium aims to identify general principles that explain not simply how gene expression changes, but why proteins are expressed at the levels we observe.

Variation generated by mutations underpins evolution, yet mutations do not arise uniformly. Rates vary enormously between mutation types and loci, shaped by replication dynamics, DNA repair, sequence context, and the environment. These biases make evolution more repeatable than selection alone would predict, with certain adaptive solutions becoming more frequent and channeling independent populations down shared trajectories. Biases also leave signatures of past mutational processes on the genome: signature analysis is central to cancer genomics and is beginning to see use in pathogen surveillance. Recent gains in the resolution at which mutation spectra can be measured are defining the evolution, mechanisms and impacts of biases, with answers arising in parallel in fields that rarely share a room.

The field is moving quickly. Recent work in multiple systems shows that reversing an existing bias reshapes the distribution of fitness effects; that transient mutation biases can make trajectories more predictable; and contested reports that mutation is biased away from functionally constrained regions remain unresolved. How selection shapes biases, and how far they can forecast evolution, are live questions which are actively reshaping our views of evolution.

This symposium invites work spanning experimental evolution, comparative genomics, germline spectra, clinical genomics, and evolutionary theory, to answer: How do mutation biases evolve, what mechanisms produce biases, and how much evolutionary predictability can biases actually deliver? Our aim is to bring the microbial, eukaryotic, clinical and theoretical communities into a single session, so those measuring biases and those formalising their consequences confront the same problems together.

Microbes and their interactions decisively shape the biology of their hosts. The ability of microbes to colonize hosts and cause disease depends upon, and in turn affects, their genomic background and the composition and interaction dynamics of surrounding microbial populations. The evolutionary underpinnings of this complex feedback loop represent a highly active research field at the intersection of evolutionary biology, microbiology, ecology, genomics and clinical sciences. Understanding how microbes transition to pathogenicity, adapt to specific hosts, and integrate into host-associated microbial communities will ultimately shed further light on the contribution of microbes to host health and disease.

This symposium will cover a broad range of evolutionary questions focusing on the interplay between pathogenicity, commensalism, and microbial host adaptation. We anticipate presentations to cover topics such as gene transfer in host-associated microbiomes, molecular and ecological factors of successful colonization, adaptation facilitating host jumps and cross-species pathogen transmission, and evolution along the mutualist-commensal-pathogen axis.

We aim to gather a diverse and interdisciplinary community of researchers, with contributions ranging from theoretical insights to applied approaches. By welcoming submissions across topics from the level of the species, the microbiome or the host, this symposium aims to promote a holistic understanding of the evolutionary ties between microbe-host dynamics and disease and emphasize the important role that evolutionary biology plays in tackling global health issues.

DNA and protein evolution have long been central to molecular evolutionary biology, yet RNA molecules, which carry another layer of information through their ability to adopt dynamic structures that influence stability, processing, translation and molecular interactions, have been much less studied/more peripheral to EB. RNA structures can be conserved even when their underlying sequences diverge, altered by individual mutations, or reshaped by cellular and environmental conditions. How selection acts on RNA structure, and how variation in structure contributes to phenotypic evolution, remains much less explored at population and transcriptome scales.

This symposium will examine RNA structure from both evolutionary and functional perspectives, across diverse organisms and evolutionary scales. We will ask how sequence and structure co-evolve, how compensatory mutations and structural constraints shape molecular evolution, and how changes in RNA folding can generate new regulatory functions. We will also consider how natural genetic variation, environmental responses and lineage-specific changes in RNA structure may contribute to phenotypic diversity and adaptation. We particularly welcome work across model and non-model systems that connects RNA structural variation to evolutionary processes, environmental responses or adaptation.

Recent advances in comparative genomics, high-throughput structure probing, long-read and single-molecule approaches, and computational modelling now allow RNA structure to be studied across individuals, species and evolutionary timescales. By linking these approaches to questions of selection, constraint and adaptation, this symposium will explore what we may be missing when we consider RNA sequence without considering the structures it forms.

Gene expression shapes phenotypes and evolution. Variation in gene expression arises from mutations that alter gene regulatory networks. Yet the molecular routes by which regulatory systems evolve remain incompletely understood. What are the relative contributions of cis- and trans-regulatory changes? How do sequence–function relationships, epistatic interactions, and pleiotropic effects of regulatory elements influence evolutionary trajectories? How do regulatory networks evolve under selection and drift? Can comparative and phylogenomic analyses reveal the origins and constraints of regulatory innovation?

This symposium will bring together researchers working across prokaryotic and eukaryotic systems to dissect the molecular basis of regulatory evolution. Topics will include, but are not limited to, promoters, enhancers, transcription factors and their binding sites, regulatory RNAs, transcriptional and translational machinery, chromatin remodeling, and gene regulatory networks. Particular emphasis will be placed on studies that connect changes in regulatory mechanisms and genome features to quantitative effects on gene expression, phenotypes, and evolutionary outcomes.

The symposium will highlight emerging approaches—including high-throughput mutagenesis and sequence–function mapping, comparative genomics, synthetic and reconstructed regulatory systems, computational modeling, and experimental evolution—that increasingly allow researchers to move from describing regulatory divergence to identifying its molecular causes. By bridging molecular biology and evolution, this symposium aims to unravel general principles governing how regulatory mechanisms originate, adapt, and diversify across the tree of life.

Somatic evolution is increasingly being studied using the same concepts and approaches that underpin population genetics and molecular evolution. Cancer provides the best-characterised example, but somatic lineages evolve across a wide range of contexts, shaped by spatial structure, tissue environment, immune and treatment pressures, and changes over time. In rare cases, such as transmissible cancers, somatic lineages can even persist and evolve across multiple hosts.

This symposium brings together recent work examining how these different contexts shape somatic evolutionary dynamics. We are especially interested in studies of selection and adaptation within tumours, spatial and temporal heterogeneity, metastatic progression, responses to therapy and other environmental pressures, and the evolution of transmissible cancers. The symposium will include both human and non-human systems and welcomes comparative, genomic, phylogenetic, theoretical and experimental approaches.

By bringing these systems into a common evolutionary framework, we will ask: what aspects of somatic evolution are universal, and which depend on the ecological context in which a clone evolves? Comparing somatic lineages across tissues, environments and hosts provides a unique opportunity to understand how spatial structure, selection pressures and transmission shape their emergence, persistence and adaptation.

Transposable elements (TEs) are generally viewed from the perspective of their hosts: as genomic parasites, sources of mutation, or raw material for evolutionary innovation. Yet this host-centred view captures only part of their biology. TEs are also evolving genetic lineages whose persistence depends on their capacity to replicate, spread within and between species, diversify, and overcome or coexist with host control.

This symposium aims to examine the complete evolutionary trajectories of TE lineages, from their emergence and invasion to their persistence, extinction, or integration into host biology. Across species, comparative genomics can reveal TE origins, diversification, turnover, and horizontal transfer. Within species, long-read population genomics and pangenomes can resolve insertion polymorphisms, variation in abundance and activity, and the dynamics of ongoing invasions. Over longer timescales, molecular and functional studies reveal how antagonistic interactions can lead to coexistence, domestication, and even host dependence on TE-derived functions.

Recent advances in long-read sequencing, population-scale sampling, pangenome analysis, and experimental genomics now allow these processes to be connected across biological and evolutionary scales. By bringing together researchers working in molecular biology, population genetics, comparative genomics, and evolutionary theory across diverse organisms, the symposium will move beyond cataloguing TEs toward a unified framework linking the molecular mechanisms of transposition and host control with the population dynamics and macroevolutionary histories of mobile genetic lineages.