Integrative Research Topics
GELIFES is renowned for its research on 'animal personalities', i.e., systematic individual differences in physiology or behaviour that are stable in time and consistent across contexts. The study of such individual differences is currently a hot topic in the animal and human behavioural sciences, in ecology and evolution, in the medical and pharmaceutical sciences, and also in fields like microbiology or robotics. Individual differences can be viewed from an evolutionary perspective (When and why does selection lead to the coexistence of different behavioural types? How are behavioural syndromes shaped by selection? What are the evolutionary implications of consistent individual variation within populations?) and from a mechanistic perspective (Which developmental and physiological processes give rise to consistent individual differences? How are behavioural syndromes shaped by these processes? What are the implications of these differences, e.g. for understanding individual vulnerability for disease and sensitivity for treatment?). In line with the general mission of the Adaptive Life initiative, all these questions will be approached from an integrative perspective that strives to synthesize evolutionary and mechanistic approaches in an overarching framework.
Keywords for this topic: animal personalities, behavioural syndromes, personalized medicine, diversifying selection, phenotypic plasticity, bet-hedging.
Adaptive diversity and eco-evolutionary dynamics
Organismal evolution is shaped by ecological processes, which in turn are influenced by evolutionary change. Therefore, understanding adaptation - or the lack thereof - requires the integration of evolutionary and ecological perspectives. The mechanisms underlying biological diversity at different levels of organisation are investigated: from the molecular mechanisms that generate phenotypic variation, to species interactions in ecological communities and the macro-evolutionary patterns of species diversity. Causes, consequences and maintenance of biodiversity are studied for a variety of organisms including bacteria, plants and (in)vertebrate animals, and using approaches ranging from theoretical modelling and comparative analysis to experimental evolution and field ecology.
Key patterns & processes: adaptive radiation, cognition, competition, cultural evolution, ecology of fear, facilitation, herbivory, host-parasite interactions, natural selection, niche construction, self-organisation, sexual selection, speciation.
Focal disciplines & approaches: behavioural ecology, biogeography, bioinformatics, community ecology, comparative genomics, conservation ecology, ecosystem dynamics, evolutionary systems biology, experimental ecology, experimental evolution, molecular evolution, phylogenetics, population genetics & genomics, sensory ecology, theoretical biology.
The microbiome in individual and community adaptation
Most eukaryotes live in close interaction with micro-organisms (the microbiome) and together they form a meta-organism in which natural selection occurs (hologenome theory of evolution). Given the high microbial diversity, as well as the high plasticity and rates of evolution at the population level, the host can adapt much faster to changes in environmental condition simply by altering its microbiome. Similar responses are observed in soils, where the interaction between soil microbes and plants might be modulated in response to stress conditions. For example, the bacteria that become endophytes in plants are recruited from the rhizosphere bacteria, which in turn are a subset of bulk soil. As these three environments impose very different demands on the bacteria involved, often requiring distinct metabolic adaptations, this theme could prove to be a model for fast genetic adaptation (or even speciation) and for the evolution of symbiotic interactions as termite-protist, ruminant-gut bacteria, etc. When in association with hosts, the microbiome is involved in the development and regulation of the immune response. It also plays a role in disease protection and in controlling host nutrition, which might lead to changes in host behaviour, warranting further investigation of its function and underlying mechanisms. When free-living, microbes regulate biogeochemical cycles, recycling the nutrients essential for life on earth. Soils harbour the greatest diversity of micro-organisms and the functioning of this microbiome, either as free-living microbial communities or in association with other soil organisms and plants, determines soil health.
Evolutionary medicine is a fast growing new research field within the life sciences that applies modern evolution theory to the study of health and disease. It aims at understanding not only how people become sick (based on molecular, physiological and neurobiological mechanisms), but especially why people become sick, based on our evolutionary history and general evolutionary principles. It uses key concepts in evolutionary research, such as trade-offs between different optimal solutions, different modes of Darwinian selection, our limits to adaptation, both in the past and in our currently rapidly changing world. It has yielded important progress in cancer research and immunology, but has also great potential for understanding other aspects of human biology including ageing, vulnerability to infections, cardio-metabolic diseases and psychological disorders.
Genetic architectures of adaptation
Organisms evolve in response to environmental variation through morphological, physiological and behavioural adaptations. Each phenotype has an underlying genetic network, which is defined as its genetic architecture. Intrinsic to genetic networks are epigenetic modifications that dynamically change gene expression. The outcome of genetic networks is influenced by internal and external factors, such that the same genotypes may produce different phenotypes in different environments (phenotypic and developmental plasticity). Genetic variation occurring within this architecture is subjected to selection, allowing for adaptation to a changing environment. New insights and developments in genomics enable us to investigate complex gene interaction networks underlying phenotypes, and characterize the extent of genetic variation in these networks. Combining these innovative tools with the functional genetics approaches allows us to unravel the genetic architecture of adaptations.
To understand the molecular mechanisms of the adaptive capacity of organisms in a fast changing world, it is imperative to tackle the complexity of the genetic architectures of traits and adaptations. We do this both through experimental approaches, and by studying the natural variation within and among populations. Also, understanding the significance of the many genetic differences among individuals can lead to new opportunities for disease detection, treatment or prevention. Thus, there is a strong need to study the genetic architecture of adaptive phenotypes, to uncover the mechanisms that allow this architecture to influence phenotypes and to understand the evolution and evolvability of the genetic architecture of different traits.
Lifespan and the rate of ageing are evolved traits, and an intricate part of species life histories. Variation in ageing and lifespan within populations is largely environmentally determined, and are hence susceptible to environmental change. Pathological ageing effects in e.g. the brain induce adaptive mitigating responses that combined with the pathological change, shape the ageing phenotype. In the context of healthy ageing, healthspan is of greater interest than lifespan, but the relation between healthspan on the one hand, and lifespan and the rate of ageing on the other hand is not well understood. Study of the process and evolution of ageing will provide the necessary knowledge to predict effects of environmental change on lifespan and ageing, and will guide the development of strategies to maximize human healthspan.
|Last modified:||22 November 2017 3.03 p.m.|