Jelle Boonekamp

University of Glasgow | UofG · School of Biodiversity, One Health & Veterinary Medicine

Growth trajectories of young animals are intimately connected to their fitness prospects, but we have little knowledge of growth regulation mechanisms, particularly in the wild. Insulin-like growth factor 1 (IGF-1) is a central hormone in regulating resource allocation, with higher IGF-1 levels resulting in more growth. IGF-1 levels generally incre...

Early-life conditions impact fitness, but whether the combined effect of extrinsic stressors is additive or synergistic is not well known. This is a major knowledge gap, because exposure to multiple stressors is likely to be frequent. Telomere dynamics may be instrumental when testing whether combined stressor effects are additive or synergistic, b...

Variation in developmental conditions is known to affect fitness in later life, but the mechanisms underlying this relationship remain elusive. We previously found in jackdaws Corvus monedula that larger eggs resulted in larger nestlings up to fledging. Through a cross‐foster experiment of complete clutches we tested whether this association can be...

Telomere attrition is considered a hallmark of ageing. Untangling the proximate causes of telomere attrition may therefore reveal important aspects about the ageing process. In a landmark paper in 2002 Thomas von Zglinicki demonstrated that oxidative stress accelerates telomere attrition in cell culture. In the next 20 years, oxidative stress becam...

Urban environments are expanding globally, presenting novel ecological challenges to which species might not be well adapted. Understanding whether species responses to urban living are adaptive or maladaptive is critical to predicting the future impacts of urbanisation on biodiversity. Urban breeding birds exhibit reduced reproductive investment (...

Variation in developmental conditions is known to affect fitness in later life, but the mechanisms underlying this relationship remain elusive. We previously found in jackdaws Corvus monedula that larger eggs resulted in larger nestlings up to fledging. Through a cross-foster experiment of complete clutches we tested whether this association can be...

Telomere attrition is considered a hallmark of ageing. Untangling the proximate causes of telomere attrition may therefore reveal important aspects about the ageing process. In a landmark paper in 2002 Thomas von Zglinicki demonstrated that oxidative stress causes telomere attrition in cell culture. In the next 20 years, oxidative stress became fir...

Telomere length and telomere shortening predict survival in many organisms. This raises the question of the contribution of genetic and environmental effects to variation in these traits, which is still poorly known, particularly for telomere shortening. We used experimental (cross‐fostering) and statistical (quantitative genetic ‘animal’ models) m...

Understanding how species can thrive in a range of environments is a central challenge for evolutionary ecology. There is strong evidence for local adaptation along large‐scale ecological clines in insects. However, potential adaptation among neighbouring populations differing in their environment has been studied much less. We used RAD‐sequencing...

Many organisms are capable of growing faster than they do. Restrained growth rate has functionally been explained by negative effects on lifespan of accelerated growth. However, the underlying mechanisms remain elusive. Telomere attrition has been proposed as a causal agent and has been mostly studied in endothermic vertebrates. We established that...

Telomere length (TL) and shortening rate predict survival in many organisms. Evolutionary dynamics of TL in response to survival selection depend on the presence of genetic variation that selection can act upon. However, the amount of standing genetic variation is poorly known for both TL and TL shortening rate, and has not been studied for both tr...

Because females produce and lay eggs or nurture embryos, they are constrained in the timing of their investment in reproduction. Males may have more opportunity to concentrate reproductive investment earlier in life, mating with as many females as possible soon after becoming adult. This fundamental difference leads to the prediction that because m...

Many organisms are capable of growing faster than they do. Restrained growth rate has functionally been explained by negative effects on lifespan of accelerated growth. However, the underlying mechanisms remain elusive. Telomere attrition has been proposed as a causal agent and has been studied in endothermic vertebrates. We established that telome...

The assumption that reproductive effort decreases somatic state, accelerating ageing, is central to our understanding of life‐history variation. Maximal reproductive effort early in life is predicted to be maladaptive by accelerating ageing disproportionally, decreasing fitness. Optimality theory predicts that reproductive effort is restrained earl...

Life-history theories of senescence are based on the existence of a trade-off in resource allocation between body maintenance and reproduction. This putative trade-off means that environmental and demographic factors affecting the costs of reproduction should be associated with changes in patterns of senescence. In many species, competition among m...

Telomere length (TL) predicts health and survival across taxa. Variation in TL between individuals is thought to be largely of genetic origin, but telomere inheritance is unusual, because zygotes already express a TL phenotype, the TL of the parental gametes. Offspring TL changes with paternal age in many species including humans, presumably throug...

The disposable soma theory of ageing predicts that when organisms invest in reproduction they do so by reducing their investment in body maintenance, inducing a trade‐off between reproduction and survival. Experiments on invertebrates in the lab provide support for the theory by demonstrating the predicted responses to manipulation of reproductive...

Declines in survival and performance with advancing age (senescence) have been widely documented in natural populations, but whether patterns of senescence across traits reflect a common underlying process of biological ageing remains unclear. Senescence is typically characterised via assessments of the rate of change in mortality with age (actuari...

Ecological conditions affect fitness, but mechanisms causing such effects are not well known, while evolved responses to environmental variation may depend on the underlying mechanisms. Consequences of environmental conditions vary strongly between traits, but a framework to interpret such variation is lacking. We propose that variation in trait re...

Telomere length (TL) predicts health and lifespan in humans and other organisms, making the identification of the causes of TL variation of interest. At conception, zygotes inherit genes that regulate TL during early development, but at the same time already express a phenotype, which is the TL of the parental gametes that formed the zygote. Whethe...

Telomere length (TL) has become a biomarker of increasing interest within ecology and evolutionary biology, and has been found to predict subsequent survival in some recent avian studies but not others. Here, we undertake the first formal meta-analysis to test whether there is an overall association between TL and subsequent mortality risk in verte...

Oxidative stress shortens telomeres in cell culture, but whether oxidative stress explains variation in telomere shortening in vivo at physiological oxidative stress levels is not well known. We therefore tested for correlations between six oxidative stress markers and telomere attrition in nestling birds (jackdaws Corvus monedula) that show a high...

Oxidative stress shortens telomeres in cell culture, but whether oxidative stress explains variation in telomere shortening in vivo at physiological oxi-dative stress levels is not well known. We therefore tested for correlations between six oxidative stress markers and telomere attrition in nestling birds (jackdaws Corvus monedula) that show a hig...

Food availability modulates survival in interaction with (for example) competition , disease and predators, but to what extent food availability in natural populations affects survival independent of these factors is not well known. We tested the effect of food availability on lifespan and actuarial senescence in a large population of captive zebra...

1. Biomarkers that predict fitness are instrumental in unravelling mechanisms that link environmental conditions to fitness. However, development is likely to be better canalized for traits with stronger fitness effects. As a consequence, traits that are sensitive to developmental conditions may be poor fitness predictors and vice versa, and we tes...

Iteroparous organisms face a trade-off between reproduction and survival but knowledge of whether, how and when costs of long-term increases in workload are paid is scant. We increased locomotion costs for a whole year by equipping male great tits with a backpack during breeding, removing the backpacks one year later. We applied three different tre...

Food and sex often go hand in hand because of the nutritional cost of reproduction. For Drosophila melanogaster females, this relationship is especially intimate because their offspring develop on food. Since yeast and sugars are important nutritional pillars for Drosophila, availability of these foods should inform female reproductive behaviours....

Behaviour may contribute to changes in fitness prospects with age, for example through effects of age dependent social dominance on resource access. Older individuals often have higher dominance rank, which may reflect a longer lifespan of dominants, and / or an increase in social dominance with age. In the latter case, increasing dominance could m...

Developmental stressors often have long-term fitness consequences, but linking offspring traits to fitness prospects has remained a challenge. Telomere length predicts mortality in adult birds, and may provide a link between developmental conditions and fitness prospects. Here, we examine the effects of manipulated brood size on growth, telomere dy...

Optimality theories of ageing predict that the balance between reproductive effort and somatic maintenance determines the rate of ageing. Laboratory studies find that increased reproductive effort shortens lifespan, but through increased short-term mortality rather than ageing. In contrast, high fecundity in early life is associated with accelerate...

Biomarkers of aging are essential to predict mortality and aging related diseases. Paradoxically, age itself imposes a limitation on the use of known biomarkers of aging, because their associations with mortality generally diminish with age. How this pattern arises is however not understood. With meta-analysis we show that human leucocyte telomere...

Biomarkers of aging are essential to predict mortality and aging-related diseases. Paradoxically, age itself imposes a limitation on the use of known biomarkers of aging because their associations with mortality generally diminish with age. How this pattern arises is, however, not understood. With meta-analysis we show that human leucocyte telomere...

The phenomenon of primary offspring sex ratio adjustment is being extensively studied, yet knowledge of the underlying proximate mechanism is still mainly hypothetical. Female birds are the heterogametic sex, thus potentially controlling the sex of the gamete to be fertilized. In several bird species, independent studies showed effects of maternal...

Females often select mates on the basis of sexual signals, which can be reliable indicators of male quality when the costliness of these signals prevents cheating. The immunocompetence handicap hypothesis (ICHH) provides a mechanistic explanation of these costs, by proposing a trade-off between immune function and sexual displays. This trade-off ar...

Submitted 126 The phenomenon of primary offspring sex ratio adjustment is being extensively studied, yet knowledge of the underlying proxi-mate mechanism is still mainly hypothetical. Female birds are the heterogametic sex, thus potentially controlling the sex of the gamete to be fertilized. In several bird species, independent studies showed effec...