Tom J M Van Dooren

• PhD
• Researcher at iEES Paris; Institiute of Ecology and Environmental Sciences Paris

Species richness is distributed unevenly across the tree of life and this may be influenced by the evolution of novel phenotypes that promote diversification. Viviparity has originated ~150 times in vertebrates and is considered to be an adaptation to highly variable environments. Likewise, possessing an annual life cycle is common in plants and in...

Significance Our study explains one of the riddles of mammal evolution: the strong conservation of the number of trunk vertebrae. The vertebral column and its high evolvability are considered to be of central importance for the evolution of vertebrates, which is why the constancy is both puzzling and important. We hypothesize, on biomechanical and...

Diapause is a developmental arrest present in annual killifish, whose eggs are able to survive long periods of desiccation when the temporary ponds they inhabit dry up. Diapause can occur in three different developmental stages. These differ, within and between species, in their responsiveness to different environmental cues. A role of developmenta...

Individual symmetry is believed to be advantageous and reflecting developmental stability, but frequency-dependent selection can also maintain polymorphisms of asymmetric phenotypes. There are many examples of so-called antisymmetry, where mirror image morphs occur at equal frequencies. With very few exceptions, these are caused by nongenetic varia...

Predicting the fate of small populations is essential in ecology, epidemiology and conservation biology. Small populations can go extinct quickly or can develop into large established populations. These can still go extinct through demographic stochasticity, especially when declines in mean population size or large size fluctuations drive them into...

Mammals as a rule have seven cervical vertebrae, a number which remains remarkably conserved. Occasional deviations of this number are usually due to the presence of cervical ribs on the seventh vertebra, indicating a homeotic transformation from a cervical rib-less vertebra into a thoracic rib-bearing vertebra. These transformations are often asso...

Previous genetic studies of pollinator wasps associated with a community of strangler figs (Ficus subgenus Urostigma, section Americana) in Central Panama suggest that the wasp species exhibit a range in host specificity across their host figs. To better understand factors that might contribute to this observed range of specificity, we used sticky...

Annual killifish embryos can arrest development in different diapauses and survive desiccation of temporary ponds in soil egg banks. They seem to implement diversified bet-hedging, generally seen as an adaptation to uncertain environments. Using a pragmatic eco-evolutionary model tailored to annual fish, it is investigated whether rates of embryoni...

Mammals almost always have seven cervical vertebrae. The strong evolutionary constraint on changes in this number has been broken in sloths and manatees. We have proposed that the extremely low activity and metabolic rates of these species relax the stabilizing selection against changes in the cervical count. Our hypothesis is that strong stabilizi...

Kings and queens of eusocial termites can live for decades, while queens sustain a nearly maximal fertility. To investigate the molecular mechanisms underlying their long lifespan, we carried out transcriptomics, lipidomics and metabolomics in Macrotermes natalensis on sterile short-lived workers, long-lived kings and five stages spanning twenty ye...

Motivation The understanding of physiological adaptations, of evolutionary radiations and of ecological responses to global change urges for global, comprehensive databases of the functional traits of extant organisms. The ability to maintain an adequate water balance is a critical functional property influencing the resilience of animal species to...

Eusocial termite queens achieve nearly maximal fertility throughout their extremely long life without apparent signs of aging. Termites represent, therefore, an ideal model for aging research. To investigate the molecular mechanisms underlying their long reproductive life, we carried out transcriptomic, lipidomic and metabolomic analyses on fat bod...

Background Cervical patterning abnormalities are rare in the general population, but one variant, cervical ribs, is particularly common in deceased fetuses and neonates. The discrepancy between the incidence in the general population and early mortality is likely due to indirect selection against cervical ribs. The cause for the co‐occurrence of ce...

Aim Different species assemblages of annual killifish possess replicated body size distributions yet have unique sets of species in each area of endemism. Here, we use models of trait evolution and historical biogeography to discover how size variation originated and has been restructured. Location South America. Taxon Austrolebias (Cyprinodontif...

Egg size has a crucial impact on the reproductive success of a mother and the performance of her offspring. It is therefore reasonable to employ egg size as a proxy for egg content when studying variation in offspring performance. Here, we tested species differences in allometries of several egg content parameters with egg area. We measured individ...

The constancy of the number of cervical vertebrae in mammals is probably the result of selection against associated variations. A survey among patients with and without cervical ribs showed an association between miscarriage and the presence of cervical ribs. This supports the hypothesized selection against variations in cervical vertebral number.

Whether environmentally-induced changes in phenotypes can be heritable is a topic with revived interest. In plants, heritable trait variation can occur without DNA sequence mutations through epigenetic mechanisms involving DNA methylation. However, it remains unknown if this other system of inheritance responds to environmental changes and if it ca...

Egg size has a crucial impact on the reproductive success of a mother and the performance of her offspring. It is therefore reasonable to employ egg size as a proxy for egg content when studying variation in offspring performance. Here, we tested species differences in allometries of several egg content parameters with egg area. We measured individ...

Patterns of size variation in fish are supposed to be generated by growth differences, not by egg or hatchling size variation. However, annual killifish live in temporary ponds with a limited time period available for growth and reproduction. It has therefore been hypothesized that among annual killifish, hatchling size variation should be of large...

Estimating and predicting temporal trends in species richness is of general importance, but notably difficult because detection probabilities of species are imperfect and many datasets were collected in an opportunistic manner. We need to improve our capabilities to assess richness trends using datasets collected in unstandardized procedures with p...

Effects of climate change can be handled by means of mitigation and adaptation. In the biological sciences, adaptations are evolved solutions of engineering problems where organisms need to match an ecological challenge. Based on Adaptive Dynamics theory, a definition is proposed of adapted states and adaptational lags which is applicable during pe...

The study of adaptation to climate change requires that we determine what the process of adaptation would converge to, and how far biological systems are removed from these adapted states at any instance. Adapted states can be polymorphic. The phenotypic variability they contain can be constructed by various processes and be assigned to different v...

Embryos of annual killifish diapause in soil egg banks while ponds are dry. Their rates of development and survival in different developmental stages determine the numbers and stages of embryos at rewetting. In the Argentinean pearlfish Austrolebias bellottii, we investigated plasticity for desiccation in such embryonal life history components acro...

Reconstructions of evolutionary and historical biogeographic processes can improve our understanding of how species assemblages developed and permit inference of ecological drivers affecting coexistence. We explore this approach in Austrolebias, a genus of annual fishes possessing a wide range of body sizes. Regional assemblages composed of differe...

Whether environmentally induced changes in phenotypes can be heritable is a topic with revived interest, in part because of observations in plants that heritable trait variation can occur without DNA sequence mutations. This other system of inheritance, called transgenerational epigenetics, typically involves differences in DNA methylation that are...

The breeder's equation generally provides robust predictions for the short-term evolution of single characters. When selection targets two or more characters simultaneously, there are often large discrepancies between predicted and observed responses. We assessed how well this standard model predicts responses to bivariate selection on wing color p...

Temporal trends (1946–2013) in the species richness of wild bees from the Netherlands are analysed. We apply two methods to estimate richness change which both incorporate models for sampling effects and detection probability. The analysis is repeated for records with specimens deposited in collections, and a subset restricted to spatial grid cells...

Background The annual life history strategy with diapauses evolved repeatedly in killifish. To understand their and to characterize their variation between species, patterns of desiccation plasticity seem central. Plasticity might have played a role in the origin of these developmental arrests, when annual fish evolved from non-annual ones. The con...

A trophic radiation in the South-American annual killifish genus Austrolebias has led to the evolution of large specialized piscivores from small generalized carnivores. It has been proposed that this occurred in a single series of vicariant speciation events. An alternative hypothesis is denoted giant-dwarf speciation: piscivores would have evolve...

Changes in pollinator abundances and diversity are of major concern. A recent study inferred that pollinator species richnesses are decreasing more slowly in recent decades in several taxa and European countries. A more careful interpretation of these results reveals that this conclusion cannot be drawn and that we can only infer that declines de...

Maternal effects are influences of maternal attributes on the offspring phenotype where the causality of the effects is not via direct genetic transmission of maternal alleles. First considered to be a nuisance parameter by animal and plant breeders, maternal effects are now increasingly perceived to be an integral part of the evolutionary process....

Grand challenges in global change research and environmental science raise the need for replicated experiments on ecosystems subjected to controlled changes in multiple environmental factors. We designed and developed the Ecolab as a variable climate and atmosphere simulator for multifactor experimentation on natural or artificial ecosystems. The E...

Recent years have seen a surge in projects that produce large volumes of structured, machine-readable biodiversity data. To make these data amenable to processing by generic, open source “data enrichment” workflows, they are increasingly being represented in a variety of standards-compliant interchange formats. Here, we report on an initiative in w...

Diapause is a developmental arrest present in annual killifish, whose eggs are able to survive long periods of desiccation when the temporary ponds they inhabit dry up. Diapause can occur in three different developmental stages. These differ, within and between species, in their responsiveness to different environmental cues. A role of developmenta...

Maturation is a developmental trait that plays a key role in shaping organisms' life-history. However, progress in understanding how maturation phenotypes evolve has been held back by confusion over how best to model maturation decisions and a lack of studies comparing genotypic variation in maturation. Here, we fitted probabilistic maturation reac...

Serotiny, the retention of mature seeds in closed fruits within the canopy for over a year, is a common trait in fire‐prone environments. When competition with adult plants prevents seedling establishment between fire events and in the absence of post‐release soil seed dormancy, strong serotiny, i.e. the retention of all seeds until the next fire,...

The fascinating and often unlikely shell shapes in the terrestrial micromollusc family Diplommatinidae (Gastropoda: Caenogastropoda) provide a particularly attractive set of multiple morphological traits to investigate evolutionary patterns of shape variation. Here, a molecular phylogenetic reconstruction, based on five genes and 2700 bp, was under...

We analyze long-term evolutionary dynamics in a large class of life history models. The model family is characterized by discrete-time population dynamics and a finite number of individual states such that the life cycle can be described in terms of a population projection matrix. We allow an arbitrary number of demographic parameters to be subject...

Reproductive effort, egg number and egg size are traditionally considered to be ‘female’ life history traits. However, females often adjust the amount of resources allocated to reproduction depending on their mate, causing male environmental effects on life history traits. If females respond to male traits which are genetically variable, then male...

Among metazoan species, left-right reversals in primary asymmetry have rarely gone to fixation. This suggests that a general mechanism suppresses the evolution of polarity reversal. Most metazoans appear externally symmetric and reproduce by external fertilization or copulation with genitalia located in the midline. Thus, reversal should generate l...

Although many species in the orchid genus Coelogyne are horticulturally popular, hardly anything is known about their pollination. Pollinators of three species were observed in the field in Nepal. This information is urgently needed because many orchid species in Nepal are endangered. Whether the exudates produced by extrafloral nectaries played a...

Sexual selection by female mating preference for male nuptial coloration has been suggested as a driving force in the rapid speciation of Lake Victoria cichlid fish. This process could have been facilitated or accelerated by genetic associations between female preference loci and male coloration loci. Preferences, as well as coloration, are heritab...

Few examples exist where parasites manipulate host behaviour not to increase their transmission rate, but their own survival. Here we investigate fitness effects of parasitism by Asobara species in relation to the pupation behaviour of the host, Drosophila melanogaster. We found that Asobara citri parasitized larvae pupate higher in rearing jars co...

In genetic polymorphisms of two alleles, heterozygous individuals may contribute to the next generation on average more or fewer descendants than the homozygotes. Two different evolutionary responses that remove a disadvantageous heterozygote phenotype from the population are the evolution of strictly assortative mate choice, and that of a modifier...

The evolutionary outcome of interspecific hybridization, i.e. collapse of species into a hybrid swarm, persistence or even divergence with reinforcement, depends on the balance between gene flow and selection against hybrids. If female mating preferences are open-ended but sign-inversed between species, they can theoretically be a source of such se...

Several hundred species of haplochromine cichlid fish have evolved rapidly in Lake Victoria. Divergent sexual and ecological selection probably played an important role in this radiation, generating divergent mating preferences and preference-trait covariance. However, the segregation of hybrid inviability or infertility genes could also potentiall...

In most animal taxa, longevity increases with body size across species, as predicted by the oxidative stress theory of aging. In contrast, in within-species comparisons of mammals and especially domestic dogs (e.g. Patronek et al., '97; Michell, '99; Egenvall et al., 2000; Speakman et al., 2003), longevity decreases with body size. We explore two d...

We analyze the consequences of diet choice behavior for the evolutionary dynamics of foraging traits by means of a mathematical model. The model is characterized by the following features. Consumers feed on two different substitutable resources that are distributed in a fine-grained manner. On encounter with a resource item, consumers decide whethe...

Why do all mammals, except for sloths and manatees, have exactly seven cervical vertebrae? In other vertebrates and other regions, the vertebral number varies considerably. We investigated whether natural selection constrains the number of cervical vertebrae in humans. To this end, we determined the incidence of cervical ribs and other homeotic ver...

Abstract Why do all mammals, except for sloths and manatees, have exactly seven cervical vertebrae? In other vertebrates and other regions, the vertebral number varies considerably. We investigated whether natural selection constrains the number of cervical vertebrae in humans. To this end, we determined the incidence of cervical ribs and other hom...

When alleles have pleiotropic effects on a number of quantitative traits, the degree of dominance between a pair of alleles can be different for each trait. Such trait-specific dominance has been studied previously in models for the maintenance of genetic variation by antagonistic effects of an allele on two fitness components. By generalizing thes...

Disruptive selection occurs when extreme phenotypes have a fitness advantage over more intermediate phenotypes. The phenomenon is particularly interesting when selection keeps a population in a disruptive regime. This can lead to increased phenotypic variation while disruptive selection itself is diminished or eliminated. Here, we review processes...

Organisms can have divergent paths of development leading to alternative phenotypes, or morphs. The choice of developmental path may be set by environmental cues, the individual's genotype, or a combination of the two. Using individual-based simulation and analytical investigation, we explore the idea that from the viewpoint of a developmental swit...

Organisms can have divergent paths of development leading to alternative phenotypes, or morphs. The choice of developmental path may be set by environmental cues, the individual’s genotype, or a combination of the two. Using individual‐based simulation and analytical investigation, we explore the idea that from the viewpoint of a developmental swit...

Levins's fitness set approach has shaped the intuition of many evolutionary ecologists about resource specialization: if the set of possible phenotypes is convex, a generalist is favored, while either of the two specialists is predicted for concave phenotype sets. An important aspect of Levins's approach is that it explicitly excludes frequency-dep...

Levins’s fitness set approach has shaped the intuition of many evolutionary ecologists about resource specialization: if the set of possible phenotypes is convex, a generalist is favored, while either of the two specialists is predicted for concave phenotype sets. An important aspect of Levins’s approach is that it explicitly excludes frequency‐dep...

Females infected with parthenogenesis-inducing Wolbachia bacteria can be cured from their infection by antibiotic treatment, resulting in male production. In most cases, however, these males are either sexually not fully functional, or infected females have lost the ability to reproduce sexually. We studied the decay of sexual function in males and...

Reaction norms for age and size at maturity are being analyzed to answer important questions about the evolution of life histories. A new statistical method is developed in the framework of time-to-event data analysis, which circumvents shortcomings in currently available approaches. The method emphasizes the estimation of age- and size-dependent m...

The haplochromine cichlids of Lake Victoria constitute a classical example of explosive speciation. Extensive intra- and interspecific variation in male nuptial coloration and female mating preferences, in the absence of postzygotic isolation between species, has inspired the hypothesis that sexual selection has been a driving force in the origin o...

Disruptive selection due to ecological causes can lead to different types of phenotypic polymorphism. For a broad range of ecological scenarios, we investigate the odds that disruptive selection leads to sexual dimorphism relative to polymorphisms that appear after evolutionary branching. These involve genetic polymorphism, such as sympatric specie...

The description of within-population variation of a signal is an important first step when studying its communicative function. In chaffinches Fringilla coelebs all song types consist of two structurally different parts: the trill (a series of two to five phrases of repeated syllables) followed by a more complex end phrase, the so-called flourish (...

When environments differentially influence male and female performance, environmental sex determination (ESD) might evolve. The conclusion from several previous theoretical models was that reaction norms for sex determination should have a single, sharp threshold, with only females being produced in some environments and only males in others. These...

The assumption that trade-offs exist is fundamental in evolutionary theory. Levins (Am. Nat. 96 (1962) 361-372) introduced a widely adopted graphical method for analyzing evolution towards an optimal combination of two quantitative traits, which are traded off. His approach explicitly excluded the possibility of density- and frequency-dependent sel...

Movement is often conditional on environmental parameters and behavioural phenotype. A reasonable assumption is that individuals behave as random walkers, when environment and behaviour are fixed. Based on this assumption, observations of movements can be analysed with a set of generalized linear models. Such models can predict the occurrence of be...

Twenty years ago, Bulmer and Bull suggested that disruptive selection, produced by environmental fluctuations, can result in an evolutionary transition from environmental sex determination (ESD) to genetic sex determination (GSD). We investigated the feasibility of such a process, using mutation-limited adaptive dynamics and individual-based comput...

Large animals generally live much longer than do small ones, and there is also a strong positive correlation between size (weight) and longevity, both in invertebrates and vertebrates. However, some studies have reported the reverse when populations or individuals within the same mammal species are compared. Rollo [1xGrowth negatively impacts the l...

Gene expression patterns of the segment polarity genes in the extended and segmented germband stage are remarkably conserved among insects. To explain the conservation of these stages, two hypotheses have been proposed. One hypothesis states that the conservation reflects a high interactivity between modules, so that mutations would have several pl...

Most developmental research focuses on a few model organisms, among which the nematode Caenorhabditis elegans is particularly prominent. Until recently, C. elegans was viewed as the ultimate deterministic organism, because there is a virtual absence of variation in cell number (eutely). However, Azevedo et al. [1xThe demise of the platonic worm. Az...

To understand the evolution of biological traits, information on the degree and origins of intraspecific variation is essential. Because adaptation can take place only if the trait shows heritable variation, it is important to know whether (at least) part of the trait variation is genetically based. We describe intra- and interindividual variation...

Two versions of a model for the evolution of seasonal polyphenism investigate the evolution of reaction norm bifurcation and branching. The first version is without a specific submodel for morphological development and the second has an explicit developmental map. Version 1 is evolutionarily relatively unconstrained: (i) reaction norms are specifie...

An evolutionary dynamical system with explicit diploid genetics is used to investigate the likelihood of observing phenotypically overdominant heterozygotes versus heterozygous phenotypes that are intermediate between the homozygotes. In this model, body size evolves in a population with discrete demographic episodes and with competition limiting r...

limited review. Views or opinions expressed herein do not necessarily represent those of the Institute, its National Member Organizations, or other organizations supporting the work. IIASA STUDIES IN ADAPTIVE DYNAMICS NO. 30 The Adaptive Dynamics Network at IIASA fosters the development of new mathematical and conceptual techniques for understandin...

To study whether absolute (m/s) or relative (body lengths/s) speed should be used to compare the vulnerability of differently sized animals, we developed a simple computer simulation. Human 'predators' were asked to 'catch' (mouse-click) prey of different sizes, moving at different speeds across a computer screen. Using the simulation, a prey's cha...

In this paper we study the evolutionary dynamics of delayed maturation in semelparous individuals. We model this in a two‐stage clonally reproducing population subject to density‐dependent fertility. The population dynamical model allows multiple — cyclic and/or chaotic — attractors, thus allowing us to illustrate how (i) evolutionary stability is...