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Introduction
I am an evolutionary ecologist interested in the role of mothers and early-life experiences on development and evolution. My research addresses this topic using comparative analyses, theoretical models and experimental tests on unusual systems (e.g., live-bearing tsetse).
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February 2012 - March 2015
October 2009 - January 2012
Publications
Publications (72)
The relationships between insect hosts and their symbionts can vary tremendously in the extent to which hosts depend on and control their symbionts. Obligate symbionts that provide micronutrients to their host are often compartmentalised to specialised host organs and depend on their hosts for survival, whereas facultative symbionts retain the abil...
The benefits of breastfeeding for the health and wellbeing of both infants and mothers are well documented, yet global breastfeeding rates are low. One factor associated with low breast feeding is maternal body mass index (BMI), which is used as a measure of obesity. The negative relationship between maternal obesity and breastfeeding is likely cau...
Critical Thermal Limits (CTLs) gauge the physiological impact of temperature on survival or critical biological function, aiding predictions of species range shifts and climatic resilience. Two recent Drosophila species studies, using similar approaches to determine temperatures that induce sterility (Thermal Fertility Limits; TFLs), reveal that TF...
Insects are the most diverse animal group on the planet. Their success is reflected by the diversity of habitats in which they live. However, these habitats have undergone great changes in recent decades; understanding how these changes affect insect health and fitness is an important challenge for insect conservation. In this Review, we focus on t...
There is growing empirical evidence that animal hosts actively control the density of their mutualistic symbionts according to their requirements. Such active regulation can be facilitated by compartmentalization of symbionts within host tissues, which confers a high degree of control of the symbiosis to the host. Here, we build a general theoretic...
Thermal stress during development can prime animals to cope better with similar conditions in later life. Alternatively, negative effects of thermal stress can persist across life stages and result in poorer quality adults (negative carryover effects). As mean temperatures increase due to climate change, evidence for such effects across diverse tax...
Most empirical and theoretical studies on reproductive senescence focus on observable attributes of offspring produced, such as size or postnatal survival. While harder to study, an important outcome of reproduction for a breeding individual is whether a viable offspring is produced at all. While prenatal mortality can sometimes be directly observe...
South American tomato pinworm, Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae) is a devastating invasive global insect pest of tomato, Solanum lycopersicum (Solanaceae). In nature, pests face multiple overlapping environmental stressors, which may significantly influence survival. To cope with rapidly changing environments, insects often employ...
Background: Stress experienced by mothers during pregnancy can have both immediate and long-term effects on child development, potentially mediated by breastfeeding.
Aim: Using a UK birth cohort study, we asked how maternal stress relates to breastfeeding and consequences for growth and puberty onset.
Subjects and methods: We analysed data from the...
Insects with access to finite energy resources must allocate these between maintenance and reproduction in a way that maximizes fitness. This will be influenced by a range of life‐history characteristics and the environment in which any particular insect species lives. In the present study, females of the blowfly Lucilia sericata (Diptera: Callipho...
Allocation of resources to competing processes of growth, maintenance, or reproduction is arguably a key process driving the physiology of life history trade‐offs and has been shown to affect immune defenses, the evolution of aging, and the evolutionary ecology of offspring quality. Here, we develop a framework to investigate the evolutionary conse...
Background
It has been suggested that attempts to eradicate populations of tsetse (Glossina spp.) using stationary targets might fail because smaller, less mobile individuals are unlikely to be killed by the targets. If true, tsetse caught in stationary traps should be larger than those from mobile baits, which require less mobility on the part of...
We tested whether the early‐life environment can influence the extent of individual plasticity in a life‐history trait. We asked: can the early‐life environment explain why, in response to the same adult environmental cue, some individuals invest more than others in current reproduction? Moreover, can it additionally explain why investment in curre...
Background Life history theory predicts that mothers should adjust reproductive investment depending on benefits of current reproduction and costs of reduced future reproductive success. These costs and benefits may in turn depend on the breeding female’s social environment. Cooperative breeders provide an ideal system to test whether changes in ma...
Theory suggests females should optimize resource allocation across reproductive bouts to maximize lifetime reproduction, balancing current and future reproductive efforts according to physiological state and projected survival and reproduction. Tests of these ideas focus on long-lived vertebrates: few measure age-related reproductive output in iter...
Background
Life history theory predicts that mothers should adjust reproductive investment depending on benefits of current reproduction and costs of reduced future reproductive success. These costs and benefits may in turn depend on the breeding female’s social environment. Cooperative breeders provide an ideal system to test whether changes in ma...
Raw data imported into R for statistical analysis. Entitled “metadat2.csv” in R code
Rationale and contribution of this meta-analysis, as required
Supplemental Table
All data extracted and used. Includes notes where several effect sizes were extracted from a single paper.
In group-living mammals, the eviction of subordinate females from breeding groups by dominants may serve to reduce feeding competition or to reduce breeding competition. Here, we combined both correlational and experimental approaches to investigate whether increases in food intake by dominant females reduces their tendency to evict subordinate fem...
In group-living mammals, the eviction of subordinate females from breeding groups by dominants may serve to reduce feeding competition or to reduce breeding competition. Here, we combined both correlational and experimental approaches to investigate whether increases in food intake by dominant females reduces their tendency to evict subordinate fem...
Life-history theory predicts that nutrition influences lifespan owing to tradeoffs between allocating resources to reproduction, growth and repair. Despite occasional reports that early diet has strong effects on lifespan, it is unclear whether this prediction is generally supported by empirical studies. We conducted a meta-analysis across experime...
Life-history theory predicts that nutrition influences lifespan owing to trade-offs between allocating resources to reproduction, growth and repair. Despite occasional reports that early diet has strong effects on lifespan, it is unclear whether this prediction is generally supported by empirical studies. We conducted a meta-analysis across experim...
1. Theory predicts that mothers should adaptively adjust reproductive investment depending on current reserves and future reproductive opportunities. Females in better intrinsic state, or with more resources, should invest more in current reproduction than those with fewer resources. Across the lifespan, investment may increase as future reproducti...
In many animal societies where hierarchies govern access to reproduction, the social rank of individuals is related to their age and weight(1-5) and slow-growing animals may lose their place in breeding queues to younger 'challengers' that grow faster(5,6). The threat of being displaced might be expected to favour the evolution of competitive growt...
Development is a continuous process during which individuals gain information about their environment and adjust their phenotype accordingly. In many natural systems, individuals are particularly sensitive to early life experiences, even in the absence of later constraints on plasticity. Recent models have highlighted how the adaptive use of inform...
Development is a continuous process during which individuals gain information about their environment and adjust their phenotype accordingly. In many natural systems, individuals are particularly sensitive to early life experiences, even in the absence of later constraints on plasticity. Recent models have highlighted how the adaptive use of inform...
Maternal effects are ubiquitous in nature and affect a wide range of offspring phenotypes. Recent research suggests that maternal effects also contribute to ageing, but the theoretical basis for these observations is poorly understood. Here we develop a simple model to derive expectations for (i) if maternal effects on ageing evolve; (ii) the stren...
Life-history theory predicts that nutrition influences lifespan due to trade-offs between allocating resources to reproduction, growth and repair. Despite occasional reports that early diet has strong effects on lifespan, it is unclear whether this prediction is generally supported by empirical studies. We conducted a meta-analysis across experimen...
Life-history theory predicts that nutrition influences lifespan due to trade-offs between allocating resources to reproduction, growth and repair. Despite occasional reports that early diet has strong effects on lifespan, it is unclear whether this prediction is generally supported by empirical studies. We conducted a meta-analysis across experimen...
1. Theory predicts that mothers should adaptively adjust reproductive investment depending on current reserves and future reproductive opportunities. Females in better intrinsic state, or with more resources, should invest more in current reproduction than those with fewer resources. Across the lifespan, investment may increase as future reproducti...
Cooperative breeding systems showcase the diversity of social trajectories within and among species, ranging from the extremes of eusocial insects where individuals become irreversibly specialized as fecund queens or sterile workers, to vertebrate systems where individuals maintain the flexibility to breed throughout life. Between these extremes li...
Resetting of epigenetic marks, such as DNA methylation, in germ cells or early embryos is not always complete. Epigenetic states may therefore persist, decay or accumulate across generations. In spite of mounting empirical evidence for incomplete resetting, it is currently poorly understood whether it simply reflects stochastic noise or plays an ad...
Parents influence the development of their offspring in many ways beyond the transmission of DNA. This includes transfer of epigenetic states, nutrients, antibodies and hormones, and behavioural interactions after birth. While the evolutionary consequences of such non-genetic inheritance are increasingly well understood, less is known about how inh...
Individual variation in growth is high in cooperative breeders and may reflect plastic divergence in developmental trajectories leading to breeding vs. helping phenotypes. However, the relative importance of additive genetic variance and developmental plasticity in shaping growth trajectories is largely unknown in cooperative vertebrates. This stud...
Social and environmental factors influence key life‐history processes and population dynamics by affecting fitness‐related phenotypic traits such as body mass. The role of body mass is particularly pronounced in cooperative breeders due to variation in social status and consequent variation in access to resources. Investigating the mechanisms under...
The social niche specialization hypothesis predicts that group-living animals should specialize in particular social roles to avoid social conflict, resulting in alternative life-history strategies for different roles. Social niche specialization, coupled with role-specific life-history trade-offs, should thus generate between-individual difference...
Extraterritorial prospecting forays are an important route to fitness in many species, allowing the assessment of dispersal opportunities and often extragroup mating prior to dispersal. However, few studies have examined the factors affecting individual variation in prospecting effort and the extent to which individuals time their forays so as to m...
Data deposited in the Dryad repository: doi:10.5061/dryad.cf033.
Fig. S1. Linear interpolation of growth (black lines) during the focal windows of interest (shaded in grey).
Fig. S2. Schematic outlining timescale for growth and environmental measurements.
Table S1. Repeatability values and 95% credibility intervals for levels of the random effects...
In polygynous species, variance in reproductive success is higher in males than females. There is consequently stronger selection for competitive traits in males and early growth can have a greater influence on later fitness in males than in females. As yet, little is known about sex differences in the effect of early growth on subsequent breeding...
Resource availability plays a key role in driving variation in somatic growth and body condition, and the factors determining access to resources vary considerably across life stages. Parents and carers may exert important influences in early life, when individuals are nutritionally dependent, with abiotic environmental effects having stronger infl...
Despite its short-term costs, behaviour that appears altruistic can increase an individual's inclusive fitness by earning direct (selfish) and/or indirect (kin-selected) benefits. An evolved preference for other-regarding or helping behaviour in potential mates has been proposed as an additional mechanism by which these behaviours can yield direct...
The evolution of adaptive phenotypic plasticity relies on the presence of cues that enable organisms to adjust their phenotype to match local conditions. Although mostly studied with respect to nonsocial cues, it is also possible that parents transmit information about the environment to their offspring. Such 'anticipatory parental effects' or 'ada...
In many cooperatively breeding societies, only a few socially dominant individuals in a group breed, reproductive skew is high, and reproductive conflict is common. Surprisingly, the effects of this conflict on dominant reproductive success in vertebrate societies have rarely been investigated, especially in high-skew societies. We examine how subo...
Maternal investment in offspring development is a major determinant of the survival and future reproductive success of both the mother and her young. Mothers might therefore be expected to adjust their investment according to ecological conditions in order to maximise their lifetime fitness. In cooperatively breeding species, where helpers assist b...
Mating between relatives often results in negative fitness consequences or inbreeding depression. However, the expression of inbreeding in populations of wild cooperative mammals and the effects of environmental, maternal and social factors on inbreeding depression in these systems are currently not well understood. This study uses pedigree-based i...
Lifetime records of changes in individual size or mass in wild animals are scarce and, as such, few studies have attempted to model variation in these traits across the lifespan or to assess the factors that affect them. However, quantifying lifetime growth is essential for understanding trade-offs between growth and other life history parameters,...
Although recent models for the evolution of personality, using game theory and life-history theory, predict that individuals should differ consistently in their cooperative behaviour, consistent individual differences in cooperative behaviour have rarely been documented. In this study, we used a long-term data set on wild meerkats to quantify the r...
Individual variation in cooperation is a striking yet poorly understood feature of many animal societies, particularly in cooperative breeders where individuals assist in the care of young that are not their own. While previous research on these systems has emphasised the plasticity of helping and how it varies with current environmental and social...
Individual variation in cooperation is a striking yet poorly understood feature of many animal societies, particularly in cooperative breeders where individuals assist in the care of young that are not their own. While previous research on these systems has emphasised the plasticity of helping and how it varies with current environmental and social...
Begging by young provokes adults to provide food for them. However, eventually begging by young and provisioning by adults cease and young become nutritionally independent. Why do young cease begging and so forgo food brought to them by adults? Three explanations have been proposed: (1) adults may not respond to begging anymore and cease feeding be...
Adults vary in their generosity in provisioning the young and their sensitivity to the need of the young. Do the young modulate
their behaviour so as to specifically target more high-provisioning adults? This is especially likely in situations with mobile,
nutritionally dependent young. We studied cooperatively breeding meerkats Suricata suricatta,...
Offspring are frequently raised alongside their siblings and are provisioned early in life by adults. Adult provisioning is stimulated by offspring begging, but it is unclear how each offspring should beg, given the begging behaviour of their siblings. It has previously been suggested that siblings may compete directly through begging for a fixed l...
In many bird species with biparental care for young in the nest, hungry chicks beg repeatedly, and parents adjust their feeding rate to the call rate of young. Repetitive calling also occurs in fledglings and in some mammals where offspring follow provisioners. It is not yet clear whether, in mobile systems with dispersed young where adults cannot...
In species where young are provisioned by both parents, males commonly contribute less to parental care than females and are less responsive to variation in begging rates. Similar differences in the care of young occur among adults in cooperative breeders but fewer studies have investigated whether these are associated with differences in responsiv...
Animals that live in cooperative societies form hierarchies in which dominant individuals reap disproportionate benefits from group cooperation. The stability of these societies requires subordinates to accept their inferior status rather than engage in escalated conflict with dominants over rank. Applying the logic of animal contests to these case...
Recent studies of reproductive skew have revealed great variation in the distribution of direct fitness among group members, yet there have been surprisingly few attempts to explore the consequences of such variation for stable group size, and none that take into account the future benefits of group membership to nonbreeders. This means that the ex...
