Tim Coulson

Tim Coulson
University of Oxford | OX · Department of Zoology

PhD

About

348
Publications
99,307
Reads
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20,850
Citations
Introduction
Eco-evolutionary feedbacks, life history theory, population ecology, and phenotypic evolution
Additional affiliations
January 2013 - present
University of Oxford
Position
  • Professor (Full)
February 2000 - December 2012
Imperial College London
Position
  • Professor (Full)
January 2000 - March 2004
University of Cambridge
Position
  • Lecturer

Publications

Publications (348)
Preprint
Full-text available
1. Inferring ecological interactions is hard because we often lack suitable parametric representations to portray them. Neural ordinary differential equations (NODEs) provide a way of estimating interactions nonparametrically from time series data. NODEs, however, are slow to fit, and inferred interactions have not been truthed. 2. We provide a fas...
Article
Full-text available
Body size variation is an enigma. We do not understand why species achieve the sizes they do, and this means we also do not understand the circumstances under which gigantism or dwarfism is selected. We develop size-structured integral projection models to explore evolution of body size and life history speed. We make few assumptions and keep model...
Article
Full-text available
Iteroparous species may reproduce at many different ages, resulting in a reproductive dispersion that affects the damping of population perturbations, and varies among life histories. Since generation time (Tc$$ {T}_c $$) is known to capture aspects of life‐history variation, such as life‐history speed, does Tc$$ {T}_c $$ also determine reproductiv...
Article
Full-text available
The rate at which avian offspring grow can have consequences for survival and reproductive output as an adult and is known to vary widely among and within species. This variation is thought to be an adaptive response to cope with environmental variation. The principal environmental factors affecting growth are food availability and predation risk,...
Preprint
Full-text available
A central debate in ecology has been the long running discussion on the role of apex predators in affecting the abundance and dynamics of their prey. In terrestrial systems, research has primarily relied on correlational approaches, due to the challenge of implementing robust experiments with replication and appropriate controls. A consequence of t...
Article
Full-text available
Populations can rapidly respond to environmental change via adaptive phenotypic plasticity, which can also modify interactions between individuals and their environment, affecting population dynamics. Bird migration is a highly plastic resource‐tracking tactic in seasonal environments. However, the link between the population dynamics of migratory...
Research Proposal
Full-text available
This is an unsuccessful ERC advanced grant application from 2020. I have published the ideas behind it, but have not secured funding to do the research. If any one is interested in using / modifying these ideas to apply for a fellowship or scholarship to come to my group, please get in contact.
Preprint
Full-text available
Body size variation is an enigma. We do not understand why species achieve the sizes they do, and this means we also do not understand the circumstances under which gigantism or dwarfism is selected. We develop size-structured integral projection models to explore evolution of body size and life history speed. We make few assumptions and keep model...
Preprint
Full-text available
Body size variation is an enigma. We do not understand why species achieve the sizes they do, and this means we also do not understand the circumstances under which gigantism or dwarfism is selected. We develop size-structured integral projection models to explore evolution of body size and life history speed. We make few assumptions and keep model...
Preprint
Generation time has previously been the focus of comparative life history analyses. Here we examine three metrics: generation time T , reproductive dispersion S (the distribution of ages of reproduction), and damping time τ (time to converge to stable (st)age distribution). We use data on 633 species of animals and plants, and perform phylogenetica...
Article
Full-text available
Life-history phenotypes emerge from clusters of traits that are the product of genes and phenotypic plasticity. If the impact of the environment differs substantially between traits, then life histories might not evolve as a cohesive whole. We quantified the sensitivity of components of the life history to food availability, a key environmental dif...
Article
Full-text available
I provide a general framework for linking ecology and evolution. I start from the fact that individuals require energy, trace molecules, water, and mates to survive and reproduce, and that phenotypic resource accrual traits determine an individual’s ability to detect and acquire these resources. Optimum resource accrual traits, and their values, ar...
Article
Full-text available
Background Human disturbance alters animal movement globally and infrastructure, such as roads, can act as physical barriers that impact behaviour across multiple spatial scales. In ungulates, roads can particularly hamper key ecological processes such as dispersal and migration, which ensure functional connectivity among populations, and may be pa...
Article
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Human impacts on the natural world often generate environmental trends that can have detrimental effects on distributions of phenotypic traits. We do not have a good understanding of how deteriorating environments might impact evolutionary trajectories across multiple generations, even though effects of environmental trends are often significant in...
Article
Full-text available
The lifetime reproductive success (LRS) of individuals is affected by random events such as death, realized growth or realized reproduction, and the outcomes of these events can differ even when individuals have identical probabilities. Another source of randomness arises when these probabilities also change over time in variable environments. For...
Article
Full-text available
Phenotypic traits partly determine expected survival and reproduction and so have been used as the basis for demographic models of population dynamics. Within a population, the distribution of phenotypic traits depends upon their transmission from parents to offspring, yet we still have a limited understanding of the factors shaping phenotypic tran...
Article
Human impacts on the natural world often generate environmental trends that can have detrimental effects on distributions of phenotypic traits. We do not have a good understanding of how deteriorating environments might impact evolutionary trajectories across multiple generations, even though effects of environmental trends are often significant in...
Article
1. Dynamic energy budget (DEB) theory provides a model of the intrinsic energetic tradeoffs that shape life‐histories, in terms of fluxes of energy through biological processes. In these models, life‐histories are a function of environmental conditions and of fundamental traits of the organism relating to the acquisition, allocation, and use of ene...
Article
Full-text available
Over the past 15 years, the number of papers focused on ‘eco‐evo dynamics’ has increased exponentially (Figure 1). This pattern suggests the rapid growth of a new, integrative discipline. We argue this overstates the case. First, the terms ‘eco‐evo dynamics’ and ‘eco‐evo interactions’ are used too imprecisely. As a result, many studies that claim t...
Article
Full-text available
Inferring the functional shape of ecological and evolutionary processes from time series data can be challenging because processes are often not describable with simple equations. The dynamical coupling between variables in time series further complicates the identification of equations through model selection as the inference of a given process is...
Article
Full-text available
The mammalian gut teems with microbes, yet how hosts acquire these symbionts remains poorly understood. Research in primates suggests that microbes can be picked up via social contact, but the role of social interactions in non-group-living species remains underexplored. Here, we use a passive tracking system to collect high resolution spatiotempor...
Preprint
Full-text available
Populations can rapidly respond to environmental change via adaptive phenotypic plasticity, which can also modify interactions between individuals and their environment, affecting population dynamics. Bird migration is a highly plastic resource-tracking strategy in seasonal environments. However, the link between the population dynamics of migrator...
Preprint
Full-text available
Life-history variation reflects phenotypic variation across suites of traits. Differences among life-history strategies result from genetic differentiation, phenotypic plasticity, and genotype-by-environment interactions. If the relative strength and direction of these components differed among traits underlying a strategy, life histories might not...
Preprint
The lifetime reproductive success (LRS) of individuals is affected by random events such as death, realized growth, or realized reproduction, and the outcomes of these events can differ even when individuals have identical probabilities. Another source of randomness arises when these probabilities also change over time in variable environments. For...
Article
Full-text available
Ecologists have long desired predictive models that allow inference on population dynamics, where detailed demographic data are unavailable. Integral projection models (IPMs) allow both demographic and phenotypic outcomes at the level of the population to be predicted from the distribution of a functional trait, like body mass. In species’ where bo...
Preprint
Over the past fifteen years, the number of papers focused on “eco-evo dynamics” has increased exponentially (Figure 1). This pattern suggests the rapid growth of a new, integrative discipline. We argue that this overstates the case. First, the terms “eco-evo dynamics” and “eco-evo interactions” are used too imprecisely. As a result, many studies th...
Preprint
Full-text available
Dynamic energy budget (DEB) models provide a mechanistic description of life-histories in terms of fluxes of energy through biological processes. In these models, life-histories are a function of environmental conditions and of fundamental traits of the organism relating to the acquisition, allocation, and use of energy. These traits are described...
Article
Full-text available
Ecological systems are no longer at equilibrium, but over much of the history of the Earth, the natural world has been in stationary states, that are punctuated by periods of transience. Just because we have knocked our planet away from a stable state, doesn't mean we have to abandon the concept of equilibrium when we strive to understand the dynam...
Article
Full-text available
Climate change has been shown to induce shifts in the timing of life-history events. As a result, interactions between species can become disrupted, with potentially detrimental effects. Predicting these consequences has proven challenging. We apply structured population models to a well-characterised great tit-caterpillar model system and identify...
Preprint
Full-text available
In the 2001 film Zoolander, the lead character, played by Ben Stiller, ditches his old “Blue Steel” look and develops an exciting new ‘Magnum” look that the fashion industry enthusiastically embraces. The evil mastermind, Mr Mugato, played by Will Farrell, exclaims “The man has only one look, for Christ’s sake! … They’re the same face! Doesn’t anyb...
Article
Full-text available
Detecting contemporary evolution requires demonstrating that genetic change has occurred. Mixed effects models allow estimation of quantitative genetic parameters and are widely used to study evolution in wild populations. However, predictions of evolution based on these parameters frequently fail to match observations. Here, we applied three comm...
Preprint
Full-text available
The mammalian gut teems with beneficial microbes, yet how hosts acquire these symbionts remains poorly understood. Research in primates suggests that microbes can be picked up via social contact, but the role of social interactions in non-group-living species remains unexplored. Here, we use a passive tracking system to collect high resolution spat...
Article
Full-text available
Very little information exists on the growth rates of woodland rodents and the drivers of body size dynamics that are observed in British populations. In this study, we use mark–recapture data collected on two species living in sympatry, wood mice (Apodemus sylvaticus) and bank voles (Myodes glareolus). A third species of rodent, the yellow‐necked...
Article
Tree and grass quality on the African savannah shows seasonal variation, driving mixed-feeding herbivores to switch between browsing and grazing. During this switch, crop consumption could be an attractive alternative to browsing. We analysed elephant diet variability in the Okavango Delta, Botswana, using faecal stable isotope ratios of carbon (δ^...
Article
Full-text available
Significance Does increased mortality from novel predators or parasites always lead to decreased prey or host population sizes? Theory says no, but we have too few examples of such compensatory effects to answer this question conclusively. We address this gap using long-term data from populations recently invaded by a nematode parasite. We combine...
Article
Full-text available
Inferring the evolutionary dynamics at play during the process of speciation by analysing the genomic landscape of divergence is a major pursuit in population genomics. However, empirical assessments of genomic landscapes under varying evolutionary scenarios that are known a priori are few, thereby limiting our ability to achieve this goal. Here we...
Preprint
Full-text available
Studies of lifetime reproductive success (LRS) have shown that important random events can be in ecology and evolution. Randomness should be amplified in stochastic environments, and here we show this to be the case by computing the complete distribution of LRS when vital rates are Markovian can be readily computed by building on our recent paper (...
Article
Full-text available
Significance Demonstrating asymmetric competition in natural systems is difficult, as the effect of large individuals on small ones has to be measured, and vice versa. Numerous experiments have quantified one side of the interaction, typically the effect of large individuals on small ones. Here, we demonstrate, using a long-term study of guppies, t...
Article
Full-text available
Fluctuating population density in stochastic environments can contribute to maintain life‐history variation within populations via density‐dependent selection. We used individual‐based data from a population of Soay sheep to examine variation in life‐history strategies at high and low population density. We incorporated life‐history trade‐offs amon...
Article
Full-text available
Lifetime reproductive performance is quantified here by the LRS (lifetime reproductive success), the random number of offspring an individual produces over its lifetime. Many field studies find that distributions of LRS among individuals are non‐normal, zero‐inflated and highly skewed. These results beg the question, what is the distribution of LRS...
Article
Full-text available
Environmentally mediated changes in body size often underlie population responses to environmental change, yet this is not a universal phenomenon. Understanding when phenotypic change underlies population responses to environmental change is important for obtaining insights and robust predictions of population dynamics in a changing world. We devel...
Preprint
Full-text available
A goal of the genomic era is to infer the evolutionary dynamics at play during the process of speciation by analysing the genomic landscape of divergence. However, empirical assessments of genomic landscapes under varying evolutionary scenarios are few, limiting the ability to achieve this goal. Here we combine RAD-sequencing and individual-based s...
Preprint
Full-text available
Fitness functions are at the heart of ecology and evolution as they simultaneously determine both population dynamics and the strength of selection. We link the Breeders and Price equations with structured population models constructed from fitness functions to show how ecological and evolutionary dynamics are intimately linked, and to characterise...
Preprint
Full-text available
In this paper I provide a general framework for linking ecology and evolution. I start from the fact that individuals require energy, trace molecules, water, and mates to survive and reproduce, and that phenotypic resource accrual traits determine an individual's ability to detect and acquire these resources. Optimum traits, and their values, are d...
Article
Animal movements towards goals or targets are based upon either maximization of resource acquisition or risk avoidance, and the way animals move can reveal information about their motivation. We use hidden Markov models fitted in a Bayesian framework and hourly GPS‐fixes to distinguish animal movements into distinct states and analyse the influence...
Article
Full-text available
Global climate change is altering the timing of life history events for species living in seasonal environments. These shifts in phenology can lead to the disruption of interspecific relationships with implications for individual fitness. Predicting phenological change and its population level consequences can provide insights into population persi...
Article
Full-text available
Species simultaneously compete with and facilitate one another. Size can mediate transitions along this competition–facilitation continuum, but the consequences for demography are unclear. We orthogonally manipulated the size of a focal species, and the size and density of a heterospecific neighbour, in the field using a model marine system. We the...
Article
The way that organisms diverge into reproductively isolated species is a major question in biology. The recent accumulation of genomic data provides promising opportunities to understand the genomic landscape of divergence, which describes the distribution of differences across genomes. Genomic areas of unusually high differentiation have been call...
Preprint
Full-text available
Fitness functions are at the heart of ecology and evolution as they simultaneously determine both population dynamics and the strength of selection. We link the Breeders and Price equations with structured population models constructed from fitness functions to show how ecological and evolutionary dynamics are intimately linked. Analyses of our mod...
Article
Full-text available
Organisms can change their environment and in doing so change the selection they experience and how they evolve. Population density is one potential mediator of such interactions because high population densities can impact the ecosystem and reduce resource availability. At present, such interactions are best known from theory and laboratory experi...
Preprint
Lifetime measures of reproductive performance are quantified here by the LRS (Lifetime Reproductive Success), the number of offspring an individual produces over its lifespan. General formulas for the mean, variance and higher moments of LRS are given by van Daalen and Caswell (2017). Yet, the complete set of probabilities for LRS are often essenti...
Preprint
Full-text available
1. The way that organisms diverge into reproductively isolated species is a major question in biology. The recent accumulation of genomic data provides promising opportunities to understand the genomic landscape of divergence, which describes the distribution of differences across genomes. Genomic areas of unusually high differentiation have been c...
Preprint
Elephants can cause negative consequences for both themselves and for humans by consuming agricultural crops. It is unclear whether savanna elephant crop consumption is merely opportunistic behaviour or related to insufficient quality of natural forage. We analysed the role of vegetation quality on elephant crop consumption. We focused on the role...
Article
Full-text available
1.The extent to which prey space use actively minimises predation risk continues to ignite controversy. Methodological reasons that have hindered consensus include inconsistent measurements of predation risk, biased spatiotemporal scales at which responses are measured, and lack of robust null expectations. 2.We addressed all three challenges in a...
Article
Full-text available
The current extinction and climate change crises pressure us to predict population dynamics with ever-greater accuracy. Although predictions rest on the well-advanced theory of age-structured populations, two key issues remain poorly explored. Specifically, how the age-dependency in demographic rates and the year-to-year interactions between surviv...
Article
Island populations often differ in consistent ways from their mainland counterparts with respect to their ecology, behaviour, morphology, demography and life-history characteristics; a set of changes referred to as the ‘island syndrome’. To understand the ecological and evolutionary drivers of the island syndrome requires characterization of suites...
Article
Full-text available
We respond to Festa‐Bianchet (2019) and caution against using interpretations from the unique Ram Mountain history to justify management of mountain sheep throughout their range. Because harvest management at Ram Mountain is atypical, it is not useful in informing the management of most mountain sheep herds.