Projects available to prospective PhD candidates
Dear PhD candidate,
Thank you for showing your interest in becoming a member of GELIFES and your consideration to take up a PhD project with us. Currently, GELIFES is home to almost 170 registered PhD candidates. Recently, 25 PhD scholarship positions were filled within the Adaptive Life programme and we will be looking to fill additional scholarship positions (e.g. in collaboration with NIOZ (Texel), Macquarie University (Australia) or Chilean universities) soon. PhD positions through direct funding to GELIFES staff members are also regularly available and will be announced on the vacancies website.
However, GELIFES certainly welcomes incoming PhD (scholarship) students with their own funding from various sources, such as CSC, CAPES/CNPq, Conacyt, Conicet, Colciencias, PRONABEC, DIKTI etc. Together with prospective supervisors we invite PhD candidates to develop their own research project which may fit into one of the six integrative research themes of GELIFES. In addition, a number of clearly described PhD projects or research directions is available, that are open for candidates with their own scholarship or for which the potential supervisors possibly would have some funding as well. Please contact them for further information or contact the GELIFES PhD coordinator for more general questions.
Potential research projects (in random order)
Functional, evolutionary and physiological aspects of coping styles in rodents
The existence of persistent variation in coping style or personality between individuals within animal populations poses questions of how natural selection acts on these phenotypes, how and why these divergent coping styles can coexist and the underlying mechanisms. A number of studies indicate that individual differences in coping style are associated with fitness outcomes that vary according to shifting environmental conditions in time and space (i.e., predation, food availability, social conditions). Also, theoretical modelling suggested that consistent differences in a diversity of risk taking behaviours is linked to whether the animal has high (much to lose, therefore risk aversive) or low future expectations in terms of fitness. The aim of the current proposal is to test these hypotheses and analyze to what extent changes over generations or among individuals correspond with changes in the underlying physiology. In rodents, individual differences in trait-aggressiveness reflect the general style of coping that varies along a proactive-reactive axis. Proactive coping individuals are exploratory, risk takers, and aggressive relative to their reactive counterparts that are more risk sensitive and timid. Furthermore, it is hypothesized that proactive individuals are behaviourally rigid, act quickly in a routine-like manner and perform best under rather stable environmental conditions whereas reactive individuals are far more sensitive to environmental changes, behaviourally flexible and adapt better to novel and fluctuating environments than proactive individuals do. Following this reasoning, it has been suggested that variation along the proactive-reactive axis is maintained by fluctuating selection pressures. Moreover, the underlying physiology and neurobiology of coping styles in these rodents have been extensively studied.
To test the above mentioned hypotheses, we have excellent facilities for housing rodents in large semi-natural outdoor colonies where we can manipulate environmental conditions and monitor the animals by means of behavioural observation and RFID chip technology, as well as health monitoring via telemetry transmitters. We have ample experience with characterization of coping styles behaviourally, physiologically as well as neurobiologically.
Untangling the neurobiology of coping styles in rodents using ecologically relevant developmental approaches
In wildlife, human and laboratory animal populations a considerable variability exists among individuals in their trait-like patterns of behavioral and physiological responses to salient environmental challenges and opportunities. This individual variation in so-called stress coping styles (also termed behavioural syndromes, temperament or personalities) has an important functional role in terms of health and fitness of the individual, the maintenance of social stability of groups and population dynamics of the species. Hence, comprehensive understanding the neural and molecular determinants of coping style variation is fundamental for not only the field of biobehavioural neurosciences in probing individual disease susceptibility, but also for ecology and evolutionary biology. Emerging views suggest that the phenotypic variation in behaviour can not only be qualitatively classified in different coping styles but can also be disentangled into multiple quantitative behavioural control functions or domains, e.g., flexibility/impulse control, emotional reactivity and harm avoidance/reward processing, which each are encoded in specific neural (micro) circuitries in the brain. A key question is to what extent these different control functions are tightly linked to each other, potentially providing a constraint on developmental plasticity and evolution, or can be independently adjusted to relevant environmental cues. Earlier studies by others and us have demonstrated that early life experience and maternal effects can to some extent affect coping styles in a potentially adaptive way. Studying the neurobiology related to these behavioural changes may strongly enhance our understanding of the modular neurobiology and its plasticity of personality. Since the functioning of virtually all the relevant brain circuitries is heavily dependent on fine-tuned serotonin and dopamine signaling, it is not surprising that the control mechanisms of serotonergic and dopaminergic neuron (re)activity play an important orchestrating role in determining general coping style. Accordingly, identifying the precise neuromolecular mechanisms that give rise to individual differences in serotonin and dopamine signaling, its plasticity and relation with coping style, will provide answers to the important question of individual vulnerability and resilience for various stress-related diseases In addition, from an evolutionary and developmental point of view, determining the molecular mechanisms of coping styles are important as to provide the (epi)genetic selection units that link heritable variation in animal coping styles to environmental developmental plasticity.
We invite applications from highly motivated PhD candidates with a strong interest in both neurobiology of behaviour and neuromolecular imaging and manipulations techniques.
Cross-species social network analyses
Pervasive and mobile technologies widely available today supports human interaction, collaboration and socialisation. While doing so they also leave traces of those interactions, making the mining of social and collaborative models possible and scalable to a large population. Having these interactions precisely measured and studying them can provide important insights into human behaviour and can lead to tools that support even better people's activities (e.g., in case of social behavioral disorders). The research we propose here is an interdisciplinary one that plans to combine expertise in human and animal behaviour, social and organisational modelling, pervasive and mobile system information and communication technologies, in order to come to a deep understanding of social behaviour and the engineering of supporting tools.
We envision a cyclic research methodology that will be applied to human (Macquarie University) and rodent species (University of Groningen). This cyclic research methodology that starts from defining an ontology of social interactions and behaviours (for example a physical meeting or by group housing rodents), associate these with technological traces (e.g., the handshake of a near field communication protocol of the mobile phones of the people involved or rodent ID tracking data), create a model for representing all possible interactions (e.g., a complex network model), populating the model with experimental data, and analyse the data. This sequence of research phases can then start again with a richer definition of social interactions and later with better models.
Based on these findings, we hope to improve the quantification of social behavior and of social behavioral deficits, such as measures of social withdrawal obtained from smartphone data of schizophrenic and Alzheimer Disease patients, as well as in group housed animals in (semi-)natural environments (University of Groningen). Furthermore, we may be able to produce an ICT tool that can improve social interaction for human social disorder conditions (e.g., via an app with gamification elements; Macquarie University).
Sleep loss and brain vulnerability
While the exact functions of sleep are still unknown, it is generally thought that sleep is of crucial importance for neuronal recovery, maintenance and plasticity. Chronically restricted sleep is a widespread and serious problem in our society that may increase brain vulnerability and contribute to psychiatric diseases and aging-related disorders such as dementia and Alzheimer’s disease. The potential mechanisms underlying the relationship between insufficient sleep and brain disorders are largely unknown but may include neuroinflammatory processes and changes in cytokines regulating neuronal viability. We are developing a research line that uses rats and mice as model species to assess the consequences of restricted sleep for the sensitivity to neurodegenerative processes at various levels of organization, from specific signaling pathways to brain regions involved in cognition and emotional regulation. We invite applications from highly motivated PhD candidates with a strong interest in neurobiology and an affinity with molecular techniques.
Evolutionary mechanisms underlying sociality - Relevance to health and disease
The degree to which an individual tends to associate with others, known as sociality, is a major determinant of an individual’s health and reproductive fitness. Social isolation, for instance, is connected with increased aggressive behavior and stress in both vertebrates and invertebrates. These evolutionary conserved responses to social isolation strongly suggests positive selection on genetic variants and epigenetic regulation of genes that contribute to neurobiological mechanisms regulating association with others. Furthermore, social isolation is an early symptom in depression and schizophrenia in humans, suggesting the involvement of evolutionary conserved processes in the early stages of these neuropsychiatric diseases. By using an integrated behavioural genetics approach in human subjects, mice and insects, this project aims to identify ultimate and proximate conserved mechanisms that promote sociality. Using time-efficient and phenotype-driven genetic approaches in the fruit fly, new genetic loci for sociality will be identified using a paradigm consisting in chronic social isolation followed by acute social exposure. Association of these Drosophila candidate loci with human sociality will be tested in two human cohorts, namely an existing large human population-based cohort and a human cohort focusing on depressive patients in which social exploratory behaviour data (using smartphone technology) and epigenetic data for selected loci will be obtained (in collaboration with UMCG partners). Genome-wide genetic variation data has already been collected in these human subjects. Patients with depression have been selected for this study, as they show increased social isolation and reduced motivation to actively engage in social interactions. Finally, the newly identified Drosophila “social” loci and human candidate genes will be validated in mice using Crispr/Cas9 technology to selectively alter candidate gene expression. Social group behaviour in these genetically manipulated mice will be studied using a newly implemented and automated Visible Burrow System, a behavioural set-up to study semi-natural social group dynamics in rodent species. Together, these studies will reveal novel ultimate and proximate mechanisms underlying sociality that may increase our understanding of pathophysiological processes underlying social withdrawal observed in a wide variety of brain disorders, such as Major Depression, Alzheimer’s Disease and Schizophrenia.
Individual differences in adaptation to climate extremes
The extent to which individual and species can adapt to climate change is currently an important topic for society and science alike. We have, in collaboration with the university of Chile, access to a non-migratory bird species, the thorn-tailed rayadito (Aphrastura spinicauda), that breeds over an enormously wide climatic gradient, from cold Patagonia to the desert in the north of Chile. This offers a unique system in which to ask how one species can adapt to such diverse climates, both from a mechanistic (proximate) and functional (ultimate) perspective. Proximate mechanisms include the possibility of phenotypic plasticity, induced by the ecological conditions experienced in early-life and adulthood. Another intriguing possibility is that of parental effects, where either prenatally (hormonal deposition in eggs) or postnatally (parental provisioning), parents programme their offspring to cope best with the prevailing ecological conditions. In both cases, phenotypic differences in breeding and survival strategy within and across populations offer an ideal opportunity to experimentally investigate the pre- and post-natal mechanisms underlying such differences. Ultimate aspects include investigating how differences in these strategies are optimized under different climatic conditions in order to maximise fitness. The project will include fieldwork in different climatic zones across Chile, under guidance from the supervisory team including Prof. Rodrigo Vásquez (University of Chile), being the leading expert of this specific study system and one of the best known behavioural ecologists in South America, Prof. Ton Groothuis (GELIFES), having expertise in bird behavioural endocrinology and maternal effects, and Prof. Jan Komdeur (GELIFES), having expertise in avian evolutionary ecology and experimental field studies. We are seeking a PhD candidate who is interested in the topics outlined above. The successful candidate will design her/his own PhD project in close collaboration with the PIs.
Evolutionary ecology of fruitfly mating dynamics - Comparing apples and pears
What constitutes nutritious food is highly species-specific, and so is what constitutes and appropriate mate. Interestingly, the availability of food can be a strong determinant of an individual’s readiness to mate, probably due to the high energetic cost of reproduction. Because food resources are often spatially structured, the coupling of mating with the availability of food can facilitate the evolution of assortative mating by bringing individuals with the same dietary preferences together. Sensory perception is critical for finding food as well as potential mates and the co-evolution of these two recognition systems is the basis of the sensory drive theory. We aim to give an experimental validation of this theory using Drosophila fruitflies, a model species for both behavioural genetics and ecological speciation. This will be achieved by addressing the following questions: 1) How do Drosophila (re-)mating dynamics affect the opportunity for assortative mating? 2) How does the developmental architecture of olfactory perception influence the evolution of food and mate preferences?
This project will integrate behavioural neurogenetics (identifying the molecular and neuronal basis of perceptual variation) with evolutionary ecology (experimental evolution of foraging and mating behaviour). We take advantage of genetically characterised Drosophila inbred lines, but also use outbred field populations caught on different ecologically relevant habitats, including apples and pears. Fieldwork will take you to a range of popular Drosophila hangouts, including fruit orchards and possibly even your own kitchen.
Learning about sleep from studies in fish
It is generally assumed that all animals spend a substantial part of their lives asleep; yet, the functions of this enigmatic behavioural and physiological state are still unknown, which makes it one of the biggest mysteries in life sciences. While much can be learned about sleep from comparative studies, only a few species have been examined in much detail and most of them are mammals. We plan to study sleep in fish, as they are an evolutionary old and diverse group that has adapted to a wide range of environmental conditions - but very little is known about their sleep. We aim to set up a new research line to document sleep-like states in various species of cichlids, testing traditional and novel sleep criteria at the behavioural and physiological level (e.g., colour change, behavioural reactivity, brain activity). We will further assess the role of light stimuli and different wavelengths of light in regulating the circadian sleep-wake rhythm in species that naturally live in different visual conditions. We invite applications from highly motivated PhD candidates interested in a research project that bridges the fields of neurobiology and behavioural ecology.
How does developmental and phenotypic plasticity affect the adaptive potential of populations in a time of global environmental change?
In an era of rapid environmental change, it is of great importance to understand when, whether, and to what extent organisms are able to adapt to changing conditions. Understanding the adaptive potential of a population or species requires a sound understanding of how individuals respond to their local environment. Individual responses can be largely deterministic (phenotypic plasticity) or stochastic (bet hedging), they can be reversible (phenotypic flexibility) or largely irreversible (developmental plasticity), and they can be induced genetically or epigenetically. Which type of individual response has evolved in a species will depend on the environments the species encountered in evolutionary history. It is intuitively plausible that the different types of response are affected in quite different ways by a change in the environment (such as climate change). It is also plausible that they have quite different effects on the evolvability of a species, that is, the ability of a species to evolve adequate individual responses to novel conditions. However, the mechanisms underlying individual response strategies, the functioning of these mechanisms under changing or novel conditions, and the implications of these mechanisms for the evolvability of a population are currently not well-understood.
We are seeking a PhD candidate who is interested in questions like those sketched above. The successful candidate will design her/his own PhD project in close collaboration with the PIs. Empirical work should either be focused on Seychelles warblers or cichlids, since detailed, long-term data (within and across generations) are available in these systems. It is also possible to add a theoretical component to this project. It will largely depend on the interests of the PhD candidate whether the emphasis of the project will be on the analysis of existing data, on own experiments in the field or in the lab, or on the analysis of evolutionary models.
Body-associated micro-organisms are drivers of avian ecology
Most commensal intestinal microbes exert profound and beneficial effects on their hosts. They interact in many ways with their host, and are important for many physiological (e.g., organ development, immune function) and behavioural functions of their host. On its turn, the host impacts its gut microbiota composition via diet, genotype, phenotype, immune function and behaviour. The close and complex interactions between host and microbiota have led to introduction of the ‘holobiont’ (host plus all associated microbiota) and ‘hologenome’ (host plus microbial genome) concepts, including the intriguing hypothesis that natural selection works upon the holobiont instead of only on the host. Yet, few studies have investigated the relationships between gut microbiota and the ecology and physiology of free-living vertebrate hosts. Moreover, none have investigated the causality of these relationships in free-living hosts, an essential step to demonstrate the implications of the holobiont concept on evolutionary adaptations. We want to take that essential step in an innovative and cutting-edge project on skylarks Alauda arvensis at the Aekingerzand. The PhD-student can make a head-start by using an unique collection of 400 cloacal swabs repeatedly taken from individual skylarks over multiple seasons and years. In addition we have life history data and immune function data of these skylarks, enabling to analyse the long-term relationships between the gut microbiota and the population dynamics, ecology and physiology of skylarks. Next we aim to manipulate the gut microbiota in wild skylarks to show and to understand the causal relationships between gut microbiota and host ecology and physiology. A field-friendly method to long-term alter avian gut microbiota has to be developed, using captive zebra finches Taeniopygia guttata. With this exciting gut microbiome manipulation experiment, we will greatly contribute to the understanding of the role of the interactions between gut microbiota and host in avian ecology and physiology.
Facilitation as driver of evolutionary adaptation?
In the light of ongoing global environmental change and associated loss of species diversity, it is of crucial importance to understand which mechanisms allow species to timely adapt. To address this question, several studies have focused on the adaptive capacity of species under different scenarios of increasing environmental stress. However, surprisingly few studies have incorporated species interactions under these scenarios, while it is known that species interactions importantly affect evolutionary adaptations. In particular, facilitation - positive interactions between species - plays a pivotal role in upholding taxonomic, genetic and functional plant diversity under stressful environmental conditions, and thus could promote the evolution of adaptive traits, eventually allowing species to cope with stressful environmental conditions. In this project, we would like to test this novel hypothesis by using a combination of descriptive, experimental and modelling studies in the lab and in the field. A potential model species for this study is Brachypodium distachyon, a temperate annual grass from drylands in the Mediterranean and Middle to Near East with a rapid life cycle. We are looking for a PhD candidate who is genuinely interested in ecology, evolution and physiology and is willing to help us further develop these ideas.
The eco-evo-devo of ‘animal personalities’
In virtually all animal species, ranging from spiders to birds and from squids to chimpanzees, individual differ systematically in aggressiveness, boldness, cooperativeness, activity level, and other behavioural tendencies. These differences are relatively stable in time, and variation in one kind of behaviour (e.g. nest building) is often correlated with variation in a very different kind of behaviour (e.g. exploration). Such systematic differences are referred to as ‘behavioural syndromes’ or ‘animal personalities’. Although they seem to reflect a fundamental aspect of the organization of brain and behaviour, their function, evolution, physiology and developmental plasticity are heavily debated. We are convinced that a sound understanding of the existence and structure of animal personalities requires a pluralistic approach that integrates an ecological (how do personalities reflect the environmental conditions of an organism?), an evolutionary (when do natural and sexual selection induce the emergence of personalities?), a mechanistic (what are the underlying neural and physiological mechanisms?) and a developmental (how do genes and environment interact shaping developmental plasticity?) perspective.
For this project, we are looking for an enthusiastic PhD student who is willing to join the team and develop research ideas on the emergence of animal personalities from such an integrative perspective. The ideal candidate combines an empirical and a theoretical approach, but a purely experimental or a purely theoretical project is also an option. Experiments should preferentially be based on a species that is well-characterized for its personality and can be investigated under natural, semi-natural and lab conditions, such as the three-spine stickleback for which we have excellent facilities.
|Last modified:||26 July 2017 3.05 p.m.|