Research Raoul Van Damme

Abstract

Throughout the long evolutionary history of tetrapods, multiple taxa returned to life in water from a terrestrial (or aerial) environment. Notable groups are Mesozoic marine reptiles, sirenians, and whales. Among mammals, aquatic taxa within the order Carnivora, or "meat-eaters", show an 'incomplete' transition to life in the aquatic environment: pinnipeds (true seals, sea lions, fur seals and walruses), otters, polar bears, and even the fishing cat rely heavily on water for feeding, but none are exclusively aquatic and they all still return to land to rest, give birth, etc. The transition from a terrestrial to a (semi-)aquatic lifestyle is an impactful biological shift, with multiple potential drivers and requires various physiological and anatomical adaptations. As this transition occurred independently in several carnivoran groups (Pinnipedia, Mustelidae, Ursidae, Felidae), as well as in different environments (riverine, lacustrine, and marine), it asks the following questions: Which environmental and ecological changes triggered this transition for each group? How did these carnivorans functionally adapt to life in water? What are the similarities and differences between these groups, and between aquatic carnivorans and other aquatic mammals? And, more specifically, what is the extent of morphological and functional convergence between these lineages? The MEATLOAF project aims to investigate the different evolutionary aspects of this transition in carnivorans from land to water, specifically targeting adaptations for locomotion (on land and in the water) and feeding (prey sensing, prey capture, and food processing, both above and below the water surface), using a variety of well-supported proxies. Proxies will be organized along two main approaches, which will link to one another in a two-way process: (1) a comparative approach, documenting the morphological diversity and shifts in morphology, and (2) a modelling approach, focusing on performance and loading of the recorded morphologies. Comparative aspects will include anatomical, systematic and phylogenetic analyses, all gathered in a 'classical paleontology' work package, as well as geometric morphometric and microanatomical-osteohistological packages to quantify internal and external morphology. The modelling approach will encompass functional analyses, finite element analyses, computational fluid dynamics, and musculo-skeletal modelling, each within its own work package. A synthesis of the results of these different packages will ultimately result in a time-calibrated assessment of the paleoecological and paleoenvironmental frameworks in which these groups evolved to life in water, in order to better understand the biotic and abiotic drivers of such a major, iterative transition.

Researcher(s)

• Promoter: Van Wassenbergh Sam
• Co-promoter: Aerts Peter
• Co-promoter: Van Damme Raoul
• Fellow: Dewaele Leonard

Research team(s)

• Functional Morphology

Project type(s)

• Research Project

Abstract

Nature provides an almost inexhaustible source of inspiration for innovative designs that may help to tackle many of the world's current social, economic and environmental challenges. In accordance, the potential of bioinspiration (including biomimetics and biomimicry) has become widely recognized in academia and industry. The main hurdle preventing the field of bioinspiration from delivering its promises, however, stems from differences in tools, practices and viewpoints of its practitioners, often obstructing further development towards successful products. Nature4Nature, a unique joint effort of biologists, engineers, designers and manufacturers, will immerse young doctoral researchers (DCs) in a learning environment that fully spans the inspiration, integration and implementation aspects of bioinspired design to tackle the conceptual, methodological and practical challenges. It will provide DCs (a) with a mindset and know-how to harness biodiversity into design; (b) with the theoretical background and practical skills for transferring biological model systems into engineering designs and applications; and (c) with an attitude and competence to implement bioinspired ideas in an explicit sustainable way. Nature4Nature will focus its research activities onto one model system: how to efficiently separate solid particles from liquids. Biological filtration systems have evolved repeatedly over the earth's living history. Nature4Nature will teach DCs to make the most of this rich heritage, using it as an inspiratory source for designing and manufacturing high-throughput, clog-resisting filtering systems that can help conserving and restoring the world's aquatic habitats. By fostering a new generation of researchers operating at the interface between scientific disciplines, sectors and societal actors, Nature4Nature sets out to spur innovative practices and will aid in overcoming the barriers to implementation of bioinspiration in the design process.

Researcher(s)

• Promoter: Du Bois Els
• Co-promoter: Aerts Peter
• Co-promoter: Broeckhoven Chris
• Co-promoter: Van Damme Raoul
• Co-promoter: Van Wassenbergh Sam
• Co-promoter: Watts Regan
• Fellow: Hageneder Lukas
• Fellow: Krsteska Katerina

Research team(s)

• Product development

Project website

Project type(s)

• Research Project

Abstract

Although often genetically impoverished due to founder effects, inbreeding, genetic drift, and sequential bottlenecks, island populations tend to reach high densities and manage to adapt to the local environment. This is paradoxical because low allelic diversity can lead to inbreeding depression (reduction in fitness due to deleterious recessive alleles), and, on a longer timescale, to reduced genetic adaptability of populations. How and why do island populations, despite low genetic diversity, survive, adapt, and thrive? A first possibility might be that low heterozygosity does not translate into inbreeding depression through the purging of deleterious variants. Alternatively, the fitness consequences of inbreeding may be bearable under the mild selection regimes typical for islands. However, evidence that either of these mechanisms is at work in wild populations remains scarce. In this project, I will study the "island paradox" in insular and mainland populations of the Italian wall lizard, Podarcis siculus. For the first time, the relationships between population structure, genetic diversity, whole-animal performance, and selection gradients are integratively used to unravel how insular populations overcome genetic impoverishment.

Researcher(s)

• Promoter: Van Damme Raoul
• Co-promoter: Svardal Hannes
• Fellow: Van Linden Lisa

Research team(s)

• Functional Morphology

Project type(s)

• Research Project

Abstract

The expression of osteoderms (bony deposits embedded in the dermal layer of skin in vertebrates) is thought to provide many adaptive functions, including protection against predators or sexual rivals, and aiding in thermo- and hydro-regulation. Cordyline lizards are a subfamily of Southern African lizards that exhibit substantial variation in this adaptive trait. Within this group, the Cape cliff lizard (Hemicordylus capensis) shows extensive intrecific variation. However, little is known about the evolutionary basis for this variation. This project aims to unravel the genomic basis of variation in osteoderm expression in this species, using an integrative approach that combines genomic and transcriptomic methods with phenotypic data. To this end, genetic material will be collected in the field, allowing me to assemble a reference genome for this species and produce genomic data from populations that differ in their environments. I will combine these data with phenotypic data to test for associations between genomic differentiation and phenotypic variation. Furthermore, I will collect and analyse transcriptomic data to test for differential gene expression associated with osteoderm expression variation. Overall, this project will shed light on the evolutionary basis of an ecologically important functional trait. The high-quality genomic resources to be produced will provide useful tools for the research community.

Researcher(s)

• Promoter: Svardal Hannes
• Co-promoter: Laukens Kris
• Co-promoter: Van Damme Raoul
• Fellow: Leitão Henrique

Research team(s)

• Evolutionary ecology group (EVECO)

Project type(s)

• Research Project

Abstract

In this project, I will compare ects of cognition and personality and their evolutionary trajectories in mainland and island lizards (Podarcis erhardii). Islands differ considerably from mainland habitats in a series of biotic and abiotic factors, and organisms often respond to this variation with striking phenotypic change. Because populations on different islands evolve independently, archipelagos offer unique opportunities for testing ideas concerning phenotypic plasticity and genetic evolution. The effects of insularity on the morphology, physiology, and life history of organisms have been studied extensively in many species. Changes in cognition and personality have received far less attention. Yet, such changes seem highly probable; as islands typically harbour less predators, competitors, and prey, I expect adjustments of cognitive capacity (high vs. low intelligence), cognitive style (speed vs. accuracy) and personality (fast vs. slow). By measuring these variables in individuals of several mainland and island populations, and by raising individuals with varied provenance in common garden set-ups, I hope to acquire insight into the plasticity and evolutionary flexibility of cognition and personality. To test the generality of these findings, I will extend the island-mainland comparison to other Podarcis species inhabiting isolated archipelagos.

Researcher(s)

• Promoter: Van Damme Raoul
• Co-promoter: Baeckens Simon
• Fellow: Gavriilidi Ioanna

Research team(s)

• Functional Morphology

Project type(s)

• Research Project

Abstract

Because they constitute the interface between the organism and its environment, biological surfaces play a vital role in many processes. Recently, new imaging techniques have uncovered that bio-surfaces sport a vast variety of microscale and nanoscale structures that are thought to tailor their interfacing functions. However, exactly how they do that, and why surface ornamentation can differ so dramatically among species, remains heavily unexplored. Using lizard skin as a study model, this project will investigate the functional significance and evolutionary trajectory of fine surface structures using the following integrative approach: (1) Quantifying the structural characteristics of a large number of species facing disparate environmental challenges. (2) Conducting in vivo performance measurements and behavioural observations combined with ex vivo mechanical and optics test to retrieve information on the physical properties and functionality of distinct structural arrangements. (3) Reconstructing the evolutionary history of fine surface structures of lizard skin and assessing the relative importance of convergent versus idiosyncratic evolutionary solutions. The project will combine cutting-edge bio-imaging and functional morphological technology with recent computational and phylogenetic tools. This will be achieved through multilateral interinstitutional collaboration.

Researcher(s)

• Promoter: Van Damme Raoul
• Fellow: Baeckens Simon

Research team(s)

• Functional Morphology

Project type(s)

• Research Project

Abstract

Osteoderms are bony elements that are expressed in the skin of a few disparate groups of tetrapods (i.e. in crocodiles, turtles, armadillos, and some lizard and frog species) – but not in other taxa. In humans, osteoderms are frequent complications of injury and in a few rare inherited disorders. Osteoderms spark interest because they are ecologically relevant (they are likely to function in body protection, thermoregulation and water budget maintenance, in mineral storage) but at the same time exhibit an unusually binary distribution (i.e., they are expressed completely, or not at all). The latter element facilitates research into the genomic substrate of the trait. One species of cordylid lizard, Hemicordylus capensis, uniquely displays intraspecific variation in osteoderms: the trait has evolved repeatedly and therefore is present in some populations, but not in others. The species thus offers exceptional opportunities for learning how, why and when this remarkable trait evolves. With this project, we aim to resolve those issues through a thoroughly integrated approach combining state-of-the-art genomic, functional morphological and ecological techniques. We will also explore if we can extrapolate the findings on this study system to other taxa that (occasionally) express osteoderms, including humans. The project will allow a rare complete view of the evolution of an ecologically relevant phenotypic characteristic with a remarkably discontinuous variation and an unusually disparate taxonomic distribution.

Researcher(s)

• Promoter: Van Damme Raoul
• Co-promoter: Laukens Kris
• Co-promoter: Matthysen Erik
• Co-promoter: Svardal Hannes

Research team(s)

• Functional Morphology

Project type(s)

• Research Project

Abstract

Although often genetically impoverished due to founder effects, inbreeding, genetic drift and sequential bottlenecks, island populations tend to reach high densities and manage to adapt to the local environment. This is paradoxical because low allelic diversity can lead to inbreeding depression (reduction in fitness due to deleterious recessive alleles), and, on a longer timescale, to reduced genetic adaptability of populations. How and why do island populations, despite low genetic diversity, survive, adapt, and thrive? A first possibility might be that low heterozygosity does not translate into inbreeding depression, thanks to the mitigating effects of behavioural adaptations related to mate choice; or through the purging of deleterious variants. Alternatively, the fitness consequences of inbreeding may be bearable under the mild selection regimes typical for islands. However, evidence that either of these mechanisms is at work in wild populations remains scarce. In this project, I will study the "island paradox" in insular and mainland populations of the Italian wall lizard, Podarcis siculus. For the first time, the relationships between heterozygosity, physiological performance, behaviour, selection gradients and genomic structure are integratively used to unravel how insular populations overcome genetic impoverishment.

Researcher(s)

• Promoter: Van Damme Raoul
• Co-promoter: Svardal Hannes
• Fellow: Van Linden Lisa

Research team(s)

• Functional Morphology

Project type(s)

• Research Project

Abstract

Prof. dr. Richard Shine is an evolutionary biologist at The University of Sydney and Macqaurie University in Australia, with an impressive scientific legacy. He has left his mark on evolutionary biology with fresh ideas and studies on e.g. life history evolution, phenotypic and developmental plasticity, sexual dimorphism and spatial sorting. In addition, he has convincingly demonstrated how theoretical insights in these matters can be implemented in more practical projects on, e.g., invasive species, climate change, and sustainable harvesting. As the world's most productive herpetologist, Prof. Shine has convincingly demonstrated that the study of traditional model species in ecology and evolutionary biology (mostly birds and mammals) can provide a very myopic view of biology, at the best. During his stay in Belgium, Prof. Shine will actively participate in data acquisition and analysis. and in writing papers. He will be available for consultation and for career coaching and will shine his light on science communication and new scientific strategies.

Researcher(s)

• Promoter: Van Damme Raoul

Research team(s)

• Functional Morphology

Project type(s)

• Research Project

Abstract

Some species of snakes carry horn-like appendages either on the snout or above the eyes. Interestingly, these structures have evolved independently in multiple clades of vipers (Viperidae). Pioneer herpetologists have speculated wildly on the function of these enigmatic appendages, but nobody has studied them in detail. In this project, I will test the putative role of rostral and supra-ocular horns in concealment, water uptake, mechanosensation and thermoregulation. To that end, I will carry out a combination of behavioural observations, visual modelling, vibrometry, thermography, (electron) microscopy, histology, µ-CT scanning and 3D image reconstructions, on a selection of specimens of different species. In a final step of the project, I will combine information obtained from the functional analyses with data on the distribution, ecology and natural history of viperid species (as available in the literature and online databases) to test ideas on the ecological drivers of horn evolution.

Researcher(s)

• Promoter: Van Damme Raoul
• Co-promoter: Broeckhoven Chris
• Co-promoter: Vanlanduit Steve
• Fellow: Banfi Federico

Research team(s)

• Functional Morphology

Project website

Project type(s)

• Research Project

Abstract

In this project we will compare aspects of cognition and personality of mainland and island lizards, Podarcis siculus. Islands differ considerably from mainland habitats in a series of biotic and abiotic factors, and organisms often respond to this variation with striking phenotypic change. Because populations on different islands evolve independently, archipelagos offer unique opportunities for testing ideas concerning phenotypic plasticity and genetic evolution. The effects of insularisation on the morphology and life history of organisms have been studied extensively in many species. Changes in cognition and behavioural syndromes have received far less attention. Yet, such changes seem plausible; as islands typically harbour less predators, competitors and prey, we expect adjustments of cognitive capacity (high-low intelligence), cognitive style (speed-accuracy) and personality (fast-slow), e.g. By measuring these variables in individuals of several mainland and island populations, and by raising individuals with varied provenance in common garden set-ups, we hope to acquire insight into the plasticity and evolutionary flexibility of cognition and personality.

Researcher(s)

• Promoter: Van Damme Raoul
• Co-promoter: Baeckens Simon
• Fellow: Gavriilidi Ioanna

Research team(s)

• Functional Morphology

Project type(s)

• Research Project

Abstract

Cognition is often described as the ability of an animal to acquire, process and retain information, which will influence its decision-making. One important aspect of cognition is behavioural flexibility, the capacity of an individual to change its behaviour in response to novel problems or situations. Problem-solving and learning are key factors in behavioural flexibility. Complex environments are thought to select for behavioural flexibility, because they more frequently present animals with novel situations. In this project, my main research question is how behavioural flexibility influences survival and reproductive success in both simple and complex environments. The study will mainly take place on the island Naxos on the Aegean wall lizard (Podarcis erhardii). In the first part of the study, I will look at individual variation in behavioural flexibility in a large number of lizards, and how this relates to social behaviour (dominance) and exploratory behaviour. Behavioural flexibility will be tested using a neophobia/neophilia test, a problemsolving task and a reversal learning task. These lizards will then be released into enclosures built around either simple or complex habitats to follow their survival and reproductive success for two consecutive years. I will also test whether populations of Aegean wall lizards from different habitats, including urban environments, differ in behavioural flexibility.

Researcher(s)

• Promoter: Van Damme Raoul
• Fellow: De Meester Gilles

Research team(s)

• Functional Morphology

Project type(s)

• Research Project

Abstract

The skin surface of lizards carries spectacular ornamentations, which vary in multiple aspects even among closely related species. In recent years, new imaging techniques have revealed that the variability of skin surface structures at the macroscopic level is dwarfed by the structural variation at the micro- and nanoscopic level. Some of these fine structures have received ample attention, such as the nanostructures on the feet of geckos responsible for the animals' remarkable adhering capacities, which have inspired the super-adhesive biomaterial Geckskin™. However, in most cases, the exact functions of fine surface structures and the evolutionary and ecological reasons why they vary so dramatically among species remain unexplored. To fill in this hiatus, this project will visualize and compare the fine surface structures of the skin of a large number of lizard species facing a range of different environmental challenges. Biomechanical and optical experiments will be conducted to assess the physical properties of skin with different fine structures, which will enable us to link structure with function. This will further allow us to reconstruct the evolutionary history of fine surface structures, and ultimately, unravel whether species evolved similar skin features to adapt to similar environments. The integrative approach of this project will be achieved by several interinstitutional and transdisciplinary collaborations and with the use of cutting-edge tools in bio-imaging.

Researcher(s)

• Promoter: Van Damme Raoul
• Fellow: Baeckens Simon

Research team(s)

• Functional Morphology

Project type(s)

• Research Project

Abstract

Through millions of years of evolution, nature has unfolded an array of armour types in the animal kingdom. The underlying mechanisms of natural body armour have received considerable attention in the field of biomimetics because of their potential role in serving as inspiration for artificial protective materials. Unfortunately, the majority of biomimetic studies often unambiguously assume that nature has selected the most optimal designs. Instead, the response of traits to natural selection is subject to various constrains including functional trade-offs. Hence, the current biomimetics approach might fail to fulfill the requisites of a well-designed biomimetics study and indirectly constrain the development of artificial body armour. The proposed project employs a strong ecological and evolutionary framework to investigate the effect of functional trade-offs on the evolution of body armour. Cordyline lizards are the ideal study system for a comparative and experimental analysis of body armour, because unlike other vertebrates, they display a vast amount of variation in the expression and morphology of osteoderms (i.e. body plates embedded in the skin). The study integrates evolutionary biology and functional morphology with the field of biomechanics while benefiting from state-of-the-art technology such as high-resolution micro-computed tomography scanning, 3D bioprinting and novel simulation software to ultimate put the current approach of biomimetic studies to the test.

Researcher(s)

• Promoter: Van Damme Raoul
• Co-promoter: Aerts Peter
• Co-promoter: Dirckx Joris
• Fellow: Broeckhoven Chris

Research team(s)

• Functional Morphology

Project website

Project type(s)

• Research Project

Abstract

Cognition is often described as the ability of an animal to acquire, process and retain information, which will influence its decision-making. One important aspect of cognition is behavioural flexibility, the capacity of an individual to change its behaviour in response to novel problems or situations. Problem-solving and learning are key factors in behavioural flexibility. Complex environments are thought to select for behavioural flexibility, because they more frequently present animals with novel situations. In this project, my main research question is how behavioural flexibility influences survival and reproductive success in both simple and complex environments. The study will mainly take place on the island Naxos on the Aegean wall lizard (Podarcis erhardii). In the first part of the study, I will look at individual variation in behavioural flexibility in a large number of lizards, and how this relates to social behaviour (dominance) and exploratory behaviour. Behavioural flexibility will be tested using a neophobia/neophilia test, a problemsolving task and a reversal learning task. These lizards will then be released into enclosures built around either simple or complex habitats to follow their survival and reproductive success for two consecutive years. I will also test whether populations of Aegean wall lizards from different habitats, including urban environments, differ in behavioural flexibility.

Researcher(s)

• Promoter: Van Damme Raoul
• Fellow: De Meester Gilles

Research team(s)

• Functional Morphology

Project website

Project type(s)

• Research Project

Abstract

The project aims to find objective indicators of welbeing in captive amphibians and reptiles. To that end, behavioural, physiological and morphological characteristics of model species living in optimal and suboptimal conditions are being monitored.

Researcher(s)

• Promoter: Van Damme Raoul
• Fellow: Borgmans Glenn

Research team(s)

• Functional Morphology

Project website

Project type(s)

• Research Project

Abstract

Animals communicate with members of their own and other species through an astonishing array of signals and displays. Just like any other biological characteristic, the organs and structures that send out and pick up signals and the signals themselves are believed to evolve. Natural selection is thought to tune communication channels according to the physical and biotic particularities of the local environment. In this project, we aim to investigate the role of the physical environment in the evolution of a chemical communication system. Lizards of the family Lacertidae deposit pheromones that contain information on the sender's species identity, its sex and its quality as a rival or sexual partner. These chemical cues are packed in a waxy substance produced by special glands on the inner thighs of the animals (the femoral glands). The lizards actively or passively deposit the femoral secretion on objects in their home range. Conspecifics pick up the cues by means of their forked tongue, which delivers the chemical particles to a specialised chemosensory organ (Jacobson's organ) in the roof of the mouth. Lacertid lizards inhabit a wide variety of habitats, from tundra over rain forests to sandy deserts. We will investigate whether and how this range of physical conditions has affected the organs producing the signals (femoral glands), the receptive system (tongue, Jacobson's organ, brain) and the chemical signal itself (physical characteristics, chemical composition).

Researcher(s)

• Promoter: Van Damme Raoul
• Co-promoter: Huyghe Katleen
• Fellow: Van Moorleghem Charlotte

Research team(s)

• Functional Morphology

Project type(s)

• Research Project

Abstract

I want to continue the artificial selection experiment that constituted the core of my first FWO-post doc mandate. In short, the experiment involves selecting male guppies (Poecilia reticulata) for dominance and for sexual attractiveness, respectively. The project is original in that it contrasts effects of intra- and intersexual selection on male phenotypes and because of its unconventional methodology (artificial selection). The experiment is currently running at full speed and the results are highly promising. After only three generations, males from the experimental lines already differ from one another and from control lines in their colouration, morphology and behaviour. It is my intention to follow up the system for at least another three generations, to see whether the evolutionary trajectories taken continue to diverge. I also want to explore whether divergent artificial selection on male phenotypes ('dominant' versus 'attractive') induces concomitant changes in female mate choice and the mate choice mind.

Researcher(s)

• Promoter: Van Damme Raoul
• Fellow: Huyghe Katleen

Research team(s)

• Functional Morphology

Project type(s)

• Research Project

Abstract

In this study, we want to get insight in the importance, challenges and ways of balance control during voluntary dynamic locomotion in quadrupedal vertebrates. Our general hypothesis is that balance is truly a major issue for the neuro-motoric system during locomotion, achieved through control of the angular momentum. Therefore, difference in locomotor behaviour and ecology must be reflected in the functional morphology and morphometrics of the sensor involved: the vestibular system.

Researcher(s)

• Promoter: Aerts Peter
• Co-promoter: Van Damme Raoul

Research team(s)

• Functional Morphology

Project type(s)

• Research Project

Abstract

This project represents a formal research agreement between UA and on the other hand the Federal Public Service. UA provides the Federal Public Service research results mentioned in the title of the project under the conditions as stipulated in this contract.

Researcher(s)

• Promoter: Van Damme Raoul

Research team(s)

• Functional Morphology

Project type(s)

• Research Project

Abstract

This project aims to identify the causes of intraspecific variation in a complex signaling system, the anoline dewlap, thereby using Anolis sagrei as model species. Specifically, I will investigate how different selective forces (predation risk, sensory drive, sexual selection and species recognition) contribute to the variation in dewlap design among A. sagrei populations on different islands in the Caribbean and within one island, Cuba.

Researcher(s)

• Promoter: Van Damme Raoul
• Fellow: Driessens Tess

Research team(s)

• Functional Morphology

Project type(s)

• Research Project

Abstract

This project investigates the ability of sperm function to respond to changes in the thermal environment. Changing temperatures affect organisms during all life stages, yet reproductive phases are considered particularly sensitive 1,2. Narrow temperature windows for reproduction have profound impacts on fitness when climates change 1,3,4. Evolutionary adaptation and adaptive plasticity (e.g. thermal acclimation) can however help species cope with temperature changes 5-7. Yet, for reproduction, and gamete function in particular, these processes remain poorly understood. This is unfortunate, since studies of weak links in the chain of biological processes are crucial to estimate the ecological risks of climate change

Researcher(s)

• Promoter: Van Damme Raoul
• Co-promoter: Aerts Peter
• Fellow: Adriaenssens Bart

Research team(s)

• Functional Morphology

Project type(s)

• Research Project

Abstract

This project represents a formal research agreement between UA and on the other hand Erasmus Mundus. UA provides Erasmus Mundus research results mentioned in the title of the project under the conditions as stipulated in this contract.

Researcher(s)

• Promoter: Van Damme Raoul

Research team(s)

• Functional Morphology

Project type(s)

• Research Project

Abstract

This project aims to identify the causes of intraspecific variation in a complex signaling system, the anoline dewlap, thereby using Anolis sagrei as model species. Specifically, I will investigate how different selective forces (predation risk, sensory drive, sexual selection and species recognition) contribute to the variation in dewlap design among A. sagrei populations on different islands in the Caribbean and within one island, Cuba.

Researcher(s)

• Promoter: Van Damme Raoul
• Co-promoter: Vanhooydonck Bieke
• Fellow: Driessens Tess

Research team(s)

• Functional Morphology

Project type(s)

• Research Project

Abstract

This project represents a formal research agreement between UA and on the other hand Erasmus Mundus. UA provides Erasmus Mundus research results mentioned in the title of the project under the conditions as stipulated in this contract.

Researcher(s)

• Promoter: Van Damme Raoul

Research team(s)

• Functional Morphology

Project type(s)

• Research Project

Abstract

This project aims to investigate the molecular origins of this recurrent melanism and tests a number of hypotheses on how it may have evolved. Many (but not all) cases of melanism in mammals and birds have been traced back to mutations in the MC1R gene, a gene that codes for a key component of the melanocortin system, which regulates the synthesis of the pigment melanin. We aim to isolate and sequence this gene in our study populations, to see whether a similar story can be told for lacertid lizards.

Researcher(s)

• Promoter: Van Damme Raoul

Research team(s)

• Functional Morphology

Project type(s)

• Research Project

Abstract

Sexual selection favors the evolution of traits that affect the reproductive success of individuals, traits that are important in male combat and male signals used by females during mate choice. As even small differences in these traits can result in a large variance in reproductive success, their evolution can be rapid and apparently unlimited. Differentiation of these traits may occur in populations with varying social conditions (e.g. density, sex-ratio) and the hypothesis of speciation by sexual selection states that when a parallel change in female mate preference and male sexual traits occurs within a population, this population might become reproductively isolated from others. With this project I will test this hypothesis, and investigate the role of sexual selection mechanisms in population divergence, and ultimately speciation. Therefore, I will use a dual approach. First, I will conduct a comparative study of natural populations of the Dalmatian wall lizard Podarcis melisellensis to describe the variation in sexual traits among populations of varying density and compare it with neutral variation and variation in naturally selected traits. Second, I will test to what extent sexual traits diverge when the social environment of a population is manipulated. This will be done by experimentally manipulating the density and sex-ratio of killifish populations (Austrolebias sp.) under laboratory conditions.

Researcher(s)

• Promoter: Van Damme Raoul
• Co-promoter: Aerts Peter
• Fellow: Huyghe Katleen

Research team(s)

• Functional Morphology

Project type(s)

• Research Project

Abstract

This project tests the hypothesis that dispersal-related traits are subjected to different selective pressures depending on the isolation and lifespan of populations. Natterjack toads are used as a model species. Toads are collected in small isolated populations as well as larger network populations, and raised in a common environment. We measure traits that are potentially related to dispersal including development, morphology, locomotion, exploratory behaviour and habitat use. Using these data we study differentiation among populations as well as associations among traits. We also determine the extent of neutral (molecular) variation among populations.

Researcher(s)

• Promoter: Matthysen Erik
• Co-promoter: Van Damme Raoul
• Fellow: Maes Joke

Research team(s)

• Evolutionary ecology group (EVECO)

Project type(s)

• Research Project

Abstract

With this project we aim at disentangling the role of (recent) selection pressures and evolutionary response on the levels of DI and its sensitivity as a measure of stress and fitness. We will compare patterns between traits that are under stabilizing selection and under recent or more ancient directional selection.

Researcher(s)

• Promoter: Van Dongen Stefan
• Co-promoter: Van Damme Raoul

Research team(s)

• Evolutionary ecology group (EVECO)

Project type(s)

• Research Project

Abstract

A trade-off exists in semi-aquatic snakes, between catching and transporting a large prey item swift and easily and catching an elusive prey underwater. The first demands a large, wide and mobile head, while the second requires a head shape that reduces the drag and should be being narrow and streamlined. In the European Dice snake, Natrix tessellata, there exists a large intra-specific variation in the diet, which can be broken up in frog versus fish eating populations. This system gives us a unique opportunity to measure the role of phenotypic plasticity in the development of local adaptations in morphology, performance and behavior in relation to differences in resource availability.

Researcher(s)

• Promoter: Van Damme Raoul
• Fellow: Brecko Jonathan

Research team(s)

• Functional Morphology

Project type(s)

• Research Project

Abstract

In the current project, I aim at elucidating the role of phenotypic plasticity in the evolution of cannibalism in annual killifish (Rivulidae, Cypridontiformes). The rivulids include all American killifish and comprise more than 300 species10. One of the most diversified genera within this family, Austrolebias, is of special interest here because all species are annual and inhabit seasonal pools formed during the rainy season.

Researcher(s)

• Promoter: Van Damme Raoul
• Fellow: Vanhooydonck Bieke

Research team(s)

• Functional Morphology

Project type(s)

• Research Project

Abstract

This project tests the hypothesis that dispersal-related traits are subjected to different selective pressures depending on the isolation and lifespan of populations. Natterjack toads are used as a model species. Toads are collected in small isolated populations as well as larger network populations, and raised in a common environment. We measure traits that are potentially related to dispersal including development, morphology, locomotion, exploratory behaviour and habitat use. Using these data we study differentiation among populations as well as associations among traits. We also determine the extent of neutral (molecular) variation among populations.

Researcher(s)

• Promoter: Matthysen Erik
• Co-promoter: Van Damme Raoul
• Fellow: Maes Joke

Research team(s)

• Evolutionary ecology group (EVECO)

Project type(s)

• Research Project

Abstract

Researcher(s)

• Promoter: Van Damme Raoul
• Co-promoter: Herrel Anthony
• Fellow: Cools Annemie

Research team(s)

• Functional Morphology

Project type(s)

• Research Project

Abstract

A trade-off exists in semi-aquatic snakes, between catching and transporting a large prey item swift and easily and catching an elusive prey underwater. The first demands a large, wide and mobile head, while the second requires a head shape that reduces the drag and should be being narrow and streamlined. In the European Dice snake, Natrix tessellata, there exists a large intra-specific variation in the diet, which can be broken up in frog versus fish eating populations. This system gives us a unique opportunity to measure the role of phenotypic plasticity in the development of local adaptations in morphology, performance and behavior in relation to differences in resource availability.

Researcher(s)

• Promoter: Van Damme Raoul
• Fellow: Brecko Jonathan

Research team(s)

• Functional Morphology

Project type(s)

• Research Project

Abstract

Researcher(s)

• Promoter: Van Damme Raoul
• Co-promoter: Backeljau Thierry
• Fellow: Hellemans Katelijne

Research team(s)

• Functional Morphology

Project type(s)

• Research Project

Abstract

In recent models of speciation, the potential role of sexual selection has been emphasized repeatedly. Still, very few studies have examined the local conditions leading to divergence in female mating preferences and male combat strategies. This project aims to compare the intensity and the targets of sexual selection in two island populations of the lizard Podarcis sicula.

Researcher(s)

• Promoter: Van Damme Raoul

Research team(s)

• Functional Morphology

Project type(s)

• Research Project

Abstract

From the very start (e.g. Darwin 1845, Wallace 1859), the faunas of island groups have played a special role in the growth of our understanding of evolutionary changes and speciation - and they continue to do so (e.g. Losos et al. 1997, 2004). Islands in archipelagos constitute repeated, discrete and relatively simple entities and therefore function as 'natura/laboratories' that can be used to test general theories (Whittaker 1998). The (often prominent) differences in phenotype (morphology, behaviour, ecology, life history) among island populations or between island and mainland populations are almost invariably attributed to genetic divergence, but it is often unclear which evolutionary processes (founder effect, genetic drift, natural selection, introgression, ...) induce these differences (Barton 1989, Clarke & Grant 1996). The alternative explanation, that the differences arise from phenotypic plasticity, is often not considered (Losos et al. 2000). In this project, we intend to take advantage of an exceptional opportunity to unravel the causes of fenotypic divergence among (island) populations.

Researcher(s)

• Promoter: Van Damme Raoul
• Co-promoter: Backeljau Thierry
• Co-promoter: Herrel Anthony
• Co-promoter: Vanhooydonck Bieke

Research team(s)

• Functional Morphology

Project type(s)

• Research Project

Abstract

Jumping in frogs is a peculiar mode of locomotion, which together with the derived anatomy of the pelvic girdle, makes it unique among vertebrates. Frog hindlimbs are much more developed than the anterior ones, the tail is vestigial and the ilia are elongated posteriorly so that the pelvic joint is located behind the sacrum. There are two major hypotheses attempting to explain origin of the saltatory locomotion in frogs and the unique derived anatomy of the locomotor apparatus. The first is largely based on the fossil record, and argues that frogs evolved from larval (i.e., water dwelling) temnospondyl amphibians (i.e. that frogs are derived from aquatic ancestors). The second hypothesis emphasizes a strictly terrestrial origin of frogs, and uses as the predominant argument against the first hypothesis that there would be no reason to modify undulatory swimming movements and to reduce the tail of the ancestral temnospondyl larvae if the transition from the pre-anuran to anuran stages would occur exclusively in water. We are convinced that this controversy cannot be solved unless we understand the functioning of the anuran pelvic girdle and its musculature during locomotion. We therefore propose to investigate terrestrial and aquatic locomotion and the anatomy of the pelvic girdle in frogs that have specialized into different locomotor modes (i.e. swimmers, jumpers, diggers and crawlers). Additionally we want to study the functioning of the locomotor system during the ontogenetic transition from water to land. This kind of data should allow for a better interpretation of the fossil evidence and allow us to determine the evolutionary origin of this unique locomotor mode.

Researcher(s)

• Promoter: Aerts Peter
• Co-promoter: Herrel Anthony
• Co-promoter: Van Damme Raoul

Research team(s)

• Functional Morphology

Project type(s)

• Research Project

Abstract

Researcher(s)

• Promoter: Van Damme Raoul
• Fellow: Brecko Jonathan

Research team(s)

• Functional Morphology

Project type(s)

• Research Project

Abstract

Researcher(s)

• Promoter: Van Damme Raoul
• Fellow: Vanhooydonck Bieke

Research team(s)

• Functional Morphology

Project type(s)

• Research Project

Abstract

Many authors (beginning with Pianka 1966) suggest that an animal has to choose between two highly different foraging strategies: sit and wait foraging (SW), where the animal stands still and waits for a suitable prey to pass by, and active foraging (AF), where the predator actively looks for the suited food. It is often supposed (among others by McLaughlin 1989) that each foraging strategy goes with a series of morphological, behavioural and ecological characteristics (like acceleration capacity, stamina, muscle composition, daily energy demands, diet, prey detection, anti-predator behaviour, habitat choice and thermoregulation). This is called the 'syndrome hypothesis'. Such dichotomy in foraging strategy and the correlated characteristics has been very popular in herpetology for a long while, although there is only little empirical evidence. Even a consensus about the quantitative characterization of an animal as SW or AF doesn't exist. It is suggested recently (see for example Perry 1999) that the dichotomy is false and that there is in fact a continuity in foraging strategies. Further were the fylogenetic relations often not taken in account in the many studies that confirmate the syndrome hypothesis. Therefore, the value of the eventually found differences can not properly determined. This study will evaluate how, within the family Lacertidae, the foraging mode is correlated with characteristics on different levels (stamina, acceleration capacity, ratio red muscle fibers/white muscle fibers in the locomotion apparatus, diet, habitat choice, chemoreceptory capacity), among others with the intention of evaluating the syndrome hypothesis. The phylogeny of the family is relatively well established, so that the interspecific comparisons can take place in an explicitely phylogenetic context. Finally, the found results could give insight in the oevolution of the studied characteristics.

Researcher(s)

• Promoter: Van Damme Raoul
• Fellow: Verwaijen Dave

Research team(s)

• Functional Morphology

Project type(s)

• Research Project

Abstract

The major aim of this project is to investigate which morphological, physiological and behavioural characteristics determine survival and reproductive success in a lacertid lizard. I will follow the research scheme proposed by Arnold (1983), which means that I will examine the relationship between design and performance (the performance gradient) and between performance and fitness (the fitness gradient). Because of the complexity of this task, I will restrict myself to one species of the Lacertidae: the Canary Island lizard Gallotia galloti. At the design level of the males of this species, I will measure some morphological (morphometry, coloration, femoral pores,...) and physiological (immune system, hormones) characteristics. Also many kinds of performance will be measured: locomotion, bite force, fighting ability and parasite load on a primary level and territorial quality, foraging success and mating success on a secondary level. Because Gallotia galloti is an ectotherm organism, body temperature is a key factor in this scheme and will have an important influence on all kinds of performance. All these design and performance parameters will be linked with each other and with survival and reproductive success, on the basis of theories and hypotheses concerning natural selection s.s., intrasexual selection (competition between males) and intersexual selection (female mate choice). These hypotheses and supposed links will be tested by correlative analyses based on field data, supplemented with laboratory experiments. During the field study (taking up several months a year on Tenerife), males will be marked to allow permanent identification and the following data will be collected: morphometry (snout vent length, body mass, head size, limb length); area of the blue chin spot; blood samples (in order to determine testosterone levels and immunocompetence); parasite load, courting behaviour and copulations; aggressive behaviour towards other males and contests; territorial area and quality. These data will allow us to investigate the link between, for instance, territorial quality and mating success or between head size and dominance. Annual survival will be estimated with capture-recapture techniques. Laboratory experiments will include: - Tests of locomotor capacity (sprint speed, endurance and manoeuvrability) in order to investigate biomechanical relationships between body shape and function, to reveal possible trade-offs between different locomotion patterns and to estimate the effect of locomotor capacity on survival. - Staged contests between males to identify parameters affecting fighting ability. The following parameters will be tested: body size, head size (relative to body size), body temperature, testosterone level, area of the blue chin spot, residence and prior experience. - Tests of female mate choice, based on visual and/or chemical signals. - Phenotypic engineering with testosterone in order to test the immunocompetence handicap hypothesis (Folstad & Karter, 1992).

Researcher(s)

• Promoter: Van Damme Raoul
• Fellow: Scheers Hans

Research team(s)

• Functional Morphology

Project type(s)

• Research Project

Abstract

Numerous examples of co-variation of morphological, physiological and behavioral traits among larval and adult stages make the Anura an ideal model for testing the idea that changes in development may constitute key innovations in evolution. It seems likely that the repeated occurrence of apparently dramatic reorganizations boil down to ontogenetic shifts (heterochrony). However, understanding the evolution of new developmental strategies in general, and the evolution of direct development (DD) in particular, requires a comparative approach, in which DD species are compared with the closest related biphasic species, in independent evolutionary lineages. The presence of such independent replica in Anura offers a unique opportunity to statistically test the existence of co-evolved 'packages' of traits, and their putative ontogenetic origin. The project combines the capacities of three research groups to study the convergent evolution of key innovations in an integrative evo-devo approach. The aim of this project is to decipher the role played by morphological and molecular heterochronic shifts during ontogeny in the ecological and phenotypical divergence of anuran lineages, through the integration of developmental biology, phylogeny and ecomorphology.

Researcher(s)

• Promoter: Van Damme Raoul

Research team(s)

• Functional Morphology

Project type(s)

• Research Project

Abstract

The major aim of this project is to investigate which morphological, physiological and behavioural characteristics determine survival and reproductive success in a lacertid lizard. I will follow the research scheme proposed by Arnold (1983), which means that I will examine the relationship between design and performance (the performance gradient) and between performance and fitness (the fitness gradient). Because of the complexity of this task, I will restrict myself to one species of the Lacertidae: the Canary Island lizard Gallotia galloti. At the design level of the males of this species, I will measure some morphological (morphometry, coloration, femoral pores,...) and physiological (immune system, hormones) characteristics. Also many kinds of performance will be measured: locomotion, bite force, fighting ability and parasite load on a primary level and territorial quality, foraging success and mating success on a secondary level. Because Gallotia galloti is an ectotherm organism, body temperature is a key factor in this scheme and will have an important influence on all kinds of performance. All these design and performance parameters will be linked with each other and with survival and reproductive success, on the basis of theories and hypotheses concerning natural selection s.s., intrasexual selection (competition between males) and intersexual selection (female mate choice). These hypotheses and supposed links will be tested by correlative analyses based on field data, supplemented with laboratory experiments. During the field study (taking up several months a year on Tenerife), males will be marked to allow permanent identification and the following data will be collected: morphometry (snout vent length, body mass, head size, limb length); area of the blue chin spot; blood samples (in order to determine testosterone levels and immunocompetence); parasite load, courting behaviour and copulations; aggressive behaviour towards other males and contests; territorial area and quality. These data will allow us to investigate the link between, for instance, territorial quality and mating success or between head size and dominance. Annual survival will be estimated with capture-recapture techniques. Laboratory experiments will include: - Tests of locomotor capacity (sprint speed, endurance and manoeuvrability) in order to investigate biomechanical relationships between body shape and function, to reveal possible trade-offs between different locomotion patterns and to estimate the effect of locomotor capacity on survival. - Staged contests between males to identify parameters affecting fighting ability. The following parameters will be tested: body size, head size (relative to body size), body temperature, testosterone level, area of the blue chin spot, residence and prior experience. - Tests of female mate choice, based on visual and/or chemical signals. - Phenotypic engineering with testosterone in order to test the immunocompetence handicap hypothesis (Folstad & Karter, 1992).

Researcher(s)

• Promoter: Aerts Peter
• Co-promoter: Van Damme Raoul
• Fellow: Scheers Hans

Research team(s)

• Functional Morphology

Project type(s)

• Research Project

Abstract

This project aims to perform such a test. Gambusia holbrooki, a small poeciliid fish, will be used as a model. The species has recently been introduced in a wide variety of thermal habitats and clearly shows the capacity to acclimate. Locomotor capacity will be used as the model function. It is generally believed that swimming speed and endurance are ecologically relevant, because they would contribute to both survival and reproductive success.

Researcher(s)

• Promoter: Aerts Peter
• Co-promoter: Van Damme Raoul
• Fellow: Adriaenssens Bart

Research team(s)

Project type(s)

• Research Project

Abstract

Motion analysis is one of the important tools in the functional morphological study of the evolution of musculo-skeletal systems as it, in combination with other functional data (such as muscle activation patterns, force measurements, etc...), allows the determination of the functional demands on the system in its ecolocical context. Whenever movement patterns can be determined externally, the analyses thereof involve the digitisation of conventional video sources (at low or high speeds, depending on the application under study ). However, often essential movements of the musculo-skeletal system of interest cannot be observed externally as the structures are covered by skin, fur or feathers (eg. movements of the pectoral and pelvic girdles in running animals, movements of the tongue and hyoid apparatus during feeding, air flow through the lungs during breathing,...). In all such cases cineradiography is "the tool of choice" to visualise these movements. In cineradiographic analysis the object under study is "illuminated" by a X-ray generator emitting pulsed or continuous X-rays. The emitted radiation is partially absorbed (depending on the density and absorption capacity of the tissue), and is received by an image intensifier and turned into a visual image. In the past, this image was generated by a phosphorising screen that, in turn, was filmed by means of a regular film camera. By synchronising the pulse frequency emitted by the generator and the shutter of the camera, movements could be recorded accurately. However, the recording speed was inherently limited by the fairly long decay time of the phosphorising screen. As for most technical applications, the recent advances in digital technology have had an enormous influence on cineradiographic techniques which has resulted in direct, digital video imaging of the cineradiographic images. This has a number of important advantages over the older technique.

Researcher(s)

• Promoter: Aerts Peter
• Co-promoter: De Vree Frits
• Co-promoter: Herrel Anthony
• Co-promoter: Van Damme Raoul

Research team(s)

• Functional Morphology

Project type(s)

• Research Project

Abstract

The major aim of this project is to investigate which morphological, physiological and behavioural characteristics determine survival and reproductive success in a lacertid lizard. I will follow the research scheme proposed by Arnold (1983), which means that I will examine the relationship between design and performance (the performance gradient) and between performance and fitness (the fitness gradient). Because of the complexity of this task, I will restrict myself to one species of the Lacertidae: the Canary Island lizard Gallotia galloti. At the design level of the males of this species, I will measure some morphological (morphometry, coloration, femoral pores,...) and physiological (immune system, hormones) characteristics. Also many kinds of performance will be measured: locomotion, bite force, fighting ability and parasite load on a primary level and territorial quality, foraging success and mating success on a secondary level. Because Gallotia galloti is an ectotherm organism, body temperature is a key factor in this scheme and will have an important influence on all kinds of performance. All these design and performance parameters will be linked with each other and with survival and reproductive success, on the basis of theories and hypotheses concerning natural selection s.s., intrasexual selection (competition between males) and intersexual selection (female mate choice). These hypotheses and supposed links will be tested by correlative analyses based on field data, supplemented with laboratory experiments. During the field study (taking up several months a year on Tenerife), males will be marked to allow permanent identification and the following data will be collected: morphometry (snout vent length, body mass, head size, limb length); area of the blue chin spot; blood samples (in order to determine testosterone levels and immunocompetence); parasite load, courting behaviour and copulations; aggressive behaviour towards other males and contests; territorial area and quality. These data will allow us to investigate the link between, for instance, territorial quality and mating success or between head size and dominance. Annual survival will be estimated with capture-recapture techniques. Laboratory experiments will include: - Tests of locomotor capacity (sprint speed, endurance and manoeuvrability) in order to investigate biomechanical relationships between body shape and function, to reveal possible trade-offs between different locomotion patterns and to estimate the effect of locomotor capacity on survival. - Staged contests between males to identify parameters affecting fighting ability. The following parameters will be tested: body size, head size (relative to body size), body temperature, testosterone level, area of the blue chin spot, residence and prior experience. - Tests of female mate choice, based on visual and/or chemical signals. - Phenotypic engineering with testosterone in order to test the immunocompetence handicap hypothesis (Folstad & Karter, 1992).

Researcher(s)

• Promoter: Aerts Peter
• Co-promoter: Van Damme Raoul
• Fellow: Scheers Hans

Research team(s)

• Functional Morphology

Project type(s)

• Research Project

Abstract

The main goal of this project is to provide a detailled picture of the current distribution of the common lizard in Flanders. In addition, in two selected areas, differing in the degree of fragmentation of the heathland habitat, we will estimate population densities and gather information on habitat quality (vegetation structure, thermal environment). These newly collected data, together with historical data on the distribution of the common lizard and its preferred habitat in Flanders, should allow to assess the effects of habitat fragmentation on this reptile species.

Researcher(s)

• Promoter: Van Damme Raoul

Research team(s)

Project type(s)

• Research Project

Abstract

In this project, we aim to assess the current distribution of amphibians in the several rural regions of Flanders, and to compare the results with data gathered 10 to 20 years ago. We want to achieve the following goals. 1)Quantify the changes in potential aquatic biotopes (ponds) and assess changes in the quality of these biotopes ; 2)Quantify changes in the number of populations of distinct species ; 3)Assess which environmental factors (characteristics of the aquatic and terrestrial habitat) best explain the presence/absence of species ; 4)Estimate the speed with which amphibians colonise new ponds; 5)Investigate the effects of management measures taken to improve the habitat quality of amphibians; 6)Contribute to the development of a methodology for monitoring amphibians and their habitats.

Researcher(s)

• Promoter: Van Damme Raoul

Research team(s)

Project type(s)

• Research Project

Abstract

My aim here is to examine in how far the locomotory apparatus of terrestrial vertebrates (in casu Sauria and Anura) is adapted to the environment. Correlations between form and function may seem obvious when comparisons are made across distantly related taxa, but more recent ecomorphological analyses have failed to establish detailed tuning of morphology to ecology in a number of more closely related species. I intend to examine possible constraints on the evolution of the locomotory apparatus by testing putative vertical and horizontal trade-offs among functions, and by assessing the steepness of fitness gradient.

Researcher(s)

• Promoter: De Vree Frits
• Fellow: Van Damme Raoul

Research team(s)

Project type(s)

• Research Project

Abstract

It is often assumed that biological evolution will inevitably lead, through the process of natural selection, to an optimal design for each ecological function. However, the adaptation process may be impeded or slowed down by constraints or trade-offs, obscuring the relationship between form and function. In theory, the adaptation process involves four stages: genetic variation may lead to variation in design which in turn may cause differences in performance for a given function, ultimately causing differential fitness (survival/reproductive success). Constraints may operate on all relationships between the stages. Here we propose an integrated and experimental study of the complete adaptation process that tackles all stages and relationships in three model species for a single function, locomotion. Locomotion is ecologically relevant since it is essential for many biological processes such as feeding, escaping from predators and dispersal. Performance can be easily quantified in terms of speed, acceleration, endurance and manoeuvrability. The model species are an insect, an amphibian and a reptile. Locomotory performance of these ectothermic animals is strongly temperature-dependent. Temperature is used as a model for the importance of fluctuating environmental parameters in evolution. The role of trade-offs in adaptation is investigated by considering interactions between different locomotory components, such as speed vs. endurance. The specific research questions are the following: (1) - What is the variation in performance? Do trade-offs exist? How does temperature influence performance? (2) - What are the mechanistic causes of variation in performance (morphological, physiological, kinematic)? (3) - Is some of the variation in performance genetically determined? (4) How does variation in performance translate to differences in survival or reproductive success? To answer these questions, the three model species will be raised in the laboratory under different temperature regimes, and performance for several locomotory components will be measured and may be followed throughout development. This is mainly done by digitization of high-speed video registrations of moving test animals and numerical analysis of the quantitative data. The obtained data on variation in performance can be correlated to parameters of design, resulting from morphometric, morphological and kinesiological research. The importance of genetic variation is assessed by measuring performance and design parameters in individuals with known relatedness (parent/offspring, sibs, half-sibs) obtained from breeding experiments (quantitative genetics). The question whether variation in performance also implies variation in fitness, is determined by comparing survival chances in laboratory or field conditions with a given predator pressure (better performing individuals are expected to have a higher chance to escape), by measuring pairing success or by directly counting the number of offspring. To achieve this research programme, the competence and expertise of three research groups of the UIA are joined. The laboratories of Functional Morphology, Ethology and Animal Ecology each have experience in research on particular aspects of the general scheme, have broad experience with research on, and raising of, model species, and most of the required facilities are present. The requested budget includes only incubators for temperature-controlled breeding experiments. The very labour-intensive nature of most of the research aspects involved in this proposal, explains why most of the requested budget is reserved for taking on additional scientific and technical personnel.

Researcher(s)

• Promoter: Aerts Peter
• Co-promoter: Matthysen Erik
• Co-promoter: Van Damme Raoul

Research team(s)

Project type(s)

• Research Project

Abstract

The aim of this study is to investigate whether the ecological and behavioural radiation within the Lacertidae is paralleled by a concordant differentiation in locomotor performance and morphology. Special attention is given to the occurence and mediation of trade-offs between different locomotory types. To be able to do so, measurements of the ecology (habitat use, foraging behaviour and anti-predatory tactics), locomotor performance (sprint speed, acceleration, endurance, manoeuverability, clinging and climbing), kinematics and morphology are taken. All these analyses are conducted in a phylogenetic context.

Researcher(s)

• Promoter: Van Damme Raoul
• Fellow: Vanhooydonck Bieke

Research team(s)

Project type(s)

• Research Project

Abstract

As a consequence of habitat fragmentation, many animal populations occur in relatively small, spatially separated units. Population dynamical and genetical theories predict that such units should be prone to extinction, unless sufficient exchange of individual animals exists among the constituent patches of habitat. However, the dispersal capacities of many species remain poorly known. In this project, we primarily study dispersion in an ectoterm with relatively low mobility: the natterjack toad (Bufo calamita). Other species (fish: Leuciscus cephalus, amphibians: Triturus spp., Alytes obstetricans) will follow.

Researcher(s)

• Promoter: Van Damme Raoul

Research team(s)

Project type(s)

• Research Project

Abstract

This study traces the effect of habitat fragmentation on the distribution and amount of genetic diversity in and among amphibian and reptillian populations. The consequences for fysiology, morphology and ecology are investigated.

Researcher(s)

• Promoter: De Vree Frits
• Fellow: Van Damme Raoul

Research team(s)

Project type(s)

• Research Project

Abstract

Via the integration of functional morphology and functional ecology, it will be examined how differences in morphology translate into differences in biological performance capabilities. Hereto, details of dynamic performance and morphological analyses will be fed into computer models. Thus, the mechanistic bases of observed variation and potential trade-offs between biological functions will be traced. Finally, heritability of, and genetic correlations between morphology and performance will be estimated. This study programme will be applied to locomotion in lacertid, and feeding in agamid lizards.

Researcher(s)

• Promoter: De Vree Frits
• Co-promoter: Aerts Peter
• Co-promoter: Van Damme Raoul

Research team(s)

Project type(s)

• Research Project

Abstract

The aim of this study is to investigate whether the ecological and behavioural radiation within the Lacertidae is paralleled by a concordant differentiation in locomotor performance and morphology. Special attention is given to the occurence and mediation of trade-offs between different locomotory types. To be able to do so, measurements of the ecology (habitat use, foraging behaviour and anti-predatory tactics), locomotor performance (sprint speed, acceleration, endurance, manoeuverability, clinging and climbing), kinematics and morphology are taken. All these analyses are conducted in a phylogenetic context.

Researcher(s)

• Promoter: Van Damme Raoul
• Fellow: Vanhooydonck Bieke

Research team(s)

Project type(s)

• Research Project

Abstract

This study traces the effect of habitat fragmentation on the distribution and amount of genetic diversity in and among amphibian and reptillian populations. The consequences for fysiology, morphology and ecology are investigated.

Researcher(s)

• Promoter: Verheyen Rudi
• Fellow: Van Damme Raoul

Research team(s)

Project type(s)

• Research Project