Living in a changing world:How the early-life environment influences animal and human ability to cope with change

Door grote veranderingen die in onze wereld plaatsvinden moeten dieren en mensen hun gedrag aanpassen aan onbekende situaties. Het succes hiervan hangt af van zowel de gebeurtenis als van het individu. De ontwikkeling van gedrag wordt sterk beïnvloed door de vroege omgeving. Belangrijke ontwikkelingsprocessen zijn ouderlijke effecten, imprinting en sociaal leren, maar deze zijn kwetsbaar voor onvoldoende of schadelijke invloeden vooral vanuit de habitat, ouders, voeding en sociale omgeving. Een studie met stekelbaarzen liet zien dat kleine verschillen tijdens de vroege omgeving al kunnen leiden tot aantoonbare verschillen in coping gedrag, zoals exploratie en sociaal- en neurotisch gedrag. Een vervolgstudie gaf aan dat het soort omgeving dat dieren ervaren tijdens hun ontwikkeling, huisvesting en experimenten van grote invloed op het coping gedrag is. Dit kan een probleem zijn voor onderzoek naar diergedrag. Ook menselijk gedrag werd bestudeerd, om oorzaak en gevolg van intergenerationele transmissie van coping gedrag – het lijken op je ouders in persoonlijkheid – beter te begrijpen. Vaderlijke afwijzing op elfjarige leeftijd was gerelateerd aan minder gelijkenis met beide ouders op zestienjarige leeftijd. Jongeren die toen meer op hun ouders leken, ervaarden in het algemeen meer welzijn en minder depressieve symptomen op negentienjarige leeftijd. Ouderlijke depressie had geen effect op dit verband. Hoewel sommige effecten van de vroege omgeving omkeerbaar zijn, is dit niet altijd het geval. Zowel dieren als mensen blijken niet helemaal vrij om zich op de meest adaptieve manier te ontwikkelen: de beschikbare opties worden beïnvloed dor de condities die tijdens het vroege leven ervaren werden.Because our world is changing in important ways, animals and humans both have to adjust their behaviour to unfamiliar situations. Whether they are successful depends on what is changing and how, but also on the individual itself. The development of coping behaviour is strongly influenced by the early-life environment, by means of developmental processes such as parental effects, imprinting and social learning. Each of these are vulnerable to insufficient or harmful influences, especially from habitat, parents, nutrition and social environment. A study on sticklebacks illustrated that small differences in early-life environment can already lead to visible differences in coping behaviours such as exploration, sociality and neuroticism. A subsequent study indicated that the environments which animals experience during development, housing and experiments all very strongly affect coping behaviour. This can be a problem for researching animal behaviour. Human behaviour was also studied, to understand cause and consequence of intergenerational transmission of coping behaviour – i.e. how people come to resemble their parents in personality, and if this is helpful. Father’s rejection at age eleven related to less resemblance with both parents at age sixteen. Youth who resembled their parents more at this point, experienced more wellbeing and less depressive symptoms at age nineteen. Parental depression did not change this relationship. Although some environmental effects are reversible, this is not always the case. Both animals and humans appear to be limited by the early-life conditions they experience in their ability to develop the most adaptive behaviour for the world they live in

Why and how the early-life environment affects development of coping behaviours

Understanding the ways in which individuals cope with threats, respond to challenges, make use of opportunities and mediate the harmful effects of their surroundings is important for predicting their ability to function in a rapidly changing world. Perhaps one of the most essential drivers of coping behaviour of adults is the environment experienced during their early-life development. Although the study of coping, defined as behaviours displayed in response to environmental challenges, has a long and rich research history in biology, recent literature has repeatedly pointed out that the processes through which coping behaviours develop in individuals are still largely unknown. In this review, we make a move towards integrating ultimate and proximate lines of coping behaviour research. After broadly defining coping behaviours (1), we review why, from an evolutionary perspective, the development of coping has become tightly linked to the early-life environment (2), which relevant developmental processes are most important in creating coping behaviours adjusted to the early-life environment (3), which influences have been shown to impact those developmental processes (4) and what the adaptive significance of intergenerational transmission of coping behaviours is, in the context of behavioural adaptations to a fast changing world (5). Important concepts such as effects of parents, habitat, nutrition, social group and stress are discussed using examples from empirical studies on mammals, fish, birds and other animals. In the discussion, we address important problems that arise when studying the development of coping behaviours and suggest solutions

Small variations in early-life environment can affect coping behaviour in response to foraging challenge in the three-spined stickleback

CONTEXT:An increasing concern in the face of human expansion throughout natural habitats is whether animal populations can respond adaptively when confronted with challenges like environmental change and novelty. Behavioural flexibility is an important factor in estimating the adaptive potential of both individuals and populations, and predicting the degree to which they can cope with change. STUDY DESIGN:This study on the three-spined stickleback (Gasterosteus aculeatus) is an empiric illustration of the degree of behavioural variation that can emerge between semi-natural systems within only a single generation. Wild-caught adult sticklebacks (P, N = 400) were randomly distributed in equal densities over 20 standardized semi-natural environments (ponds), and one year later offspring (F1, N = 652) were presented with repeated behavioural assays. Individuals were challenged to reach a food source through a novel transparent obstacle, during which exploration, activity, foraging, sociability and wall-biting behaviours were recorded through video observation. We found that coping responses of individuals from the first generation to this unfamiliar foraging challenge were related to even relatively small, naturally diversified variation in developmental environment. All measured behaviours were correlated with each other. Especially exploration, sociability and wall-biting were found to differ significantly between ponds. These differences could not be explained by stickleback density or the turbidity of the water. FINDINGS:Our findings show that a) differences in early-life environment appear to affect stickleback feeding behaviour later in life; b) this is the case even when the environmental differences are only small, within natural parameters and diversified gradually; and c) effects are present despite semi-natural conditions that fluctuate during the year. Therefore, in behaviourally plastic animals like the stickleback, the adaptive response to human-induced habitat disturbance may occur rapidly (within one generation) and vary strongly based on the system's (starting) conditions. This has important implications for the variability in animal behaviour, which may be much larger than expected from studying laboratory systems, as well as for the validity of predictions of population responses to change

Temporal variation in sex allocation in the mealybug <em>Planococcus citri</em>:Adaptation, constraint, or both?

Sex ratio theory has been very successful in predicting under which circumstances parents should bias their investment towards a particular offspring sex. However, most examples of adaptive sex ratio bias come from species with well-defined mating systems and sex determining mechanisms, while in many other groups there is still an on-going debate about the adaptive nature of sex allocation. Here we study the sex allocation in the mealybug Planococcus citri, a species in which it is currently unclear how females adjust their sex ratio, even though experiments have shown support for facultative sex ratio adjustment. Previous work has shown that the sex ratio females produce changes over the oviposition period, with males being overproduced early and late in the laying sequence. Here we investigate this complex pattern further, examining both the robustness of the pattern and possible explanations for it. We first show that this sex allocation behaviour is indeed consistent across lines from three geographical regions. Second, we test whether females produce sons first in order to synchronize reproductive maturation of her offspring, although our data provide little evidence for this adaptive explanation. Finally we test the age at which females are able to mate successfully and show that females are able to mate and store sperm before adult eclosion. Whilst early-male production may still function in promoting protandry in mealybugs, we discuss whether mechanistic constraints limit how female allocate sex across their lifetime

Controlled oxidative protein refolding using an ion-exchange column

Column-based refolding of complex and highly disulfide-bonded proteins simplifies protein renaturation at both preparative and process scale by integrating and automating a number of operations commonly used in dilution refolding. Bovine serum albumin (BSA) was used as a model protein for refolding and oxido-shuffling on an ion-exchange column to give a refolding yield of 55% after 40 h incubation. Successful on-column refolding was conducted at protein concentrations of up to 10 mg/ml and refolded protein, purified from misfolded forms, was eluted directly from the column at a concentration of 3 mg/ml. This technique integrates the dithiothreitol removal, refolding, concentration and purification steps, achieving a high level of process simplification and automation, and a significant saving in reagent costs when scaled. Importantly, the current result suggests that it is possible to controllably refold disulfide-bonded proteins using common and inexpensive matrices, and that it is not always necessary to control protein¿surface interactions using affinity tags and expensive chromatographic matrices. Moreover, it is possible to strictly control the oxidative refolding environment once denatured protein is bound to the ion-exchange column, thus allowing precisely controlled oxido-shuffling