Integrative Topics

Organismal evolution is shaped by ecological processes, which in turn are influenced by evolutionary change. Therefore, understanding adaptation - or the lack thereof - requires the integration of evolutionary and ecological perspectives. We investigate the mechanisms underlying biological diversity at different levels of organisation: from the molecular mechanisms that generate phenotypic variation, to species interactions in ecological communities and the macro-evolutionary patterns of species diversity. We study a variety of organisms including bacteria, plants and (in)vertebrate animals. Our approaches range from theoretical modelling and comparative analysis to experimental evolution and field ecology.

Keywords

Patterns and processes studied: adaptive radiation, cognition, competition, cultural evolution, ecology of fear, facilitation, herbivory, host-parasite interactions, natural selection, niche construction, self-organisation, sexual selection, speciation.

Disciplines and approaches: behavioural ecology, biogeography, bioinformatics, community ecology, comparative genomics, conservation ecology, ecosystem dynamics, evolutionary systems biology, experimental ecology, experimental evolution, molecular evolution, phylogenetics, population genetics & genomics, sensory ecology, theoretical biology.

Selected research themes

• Drivers of organismal diversity: the role of adaptive (e.g. natural and sexual selection) and non-adaptive (e.g. drift) mechanisms in differentiation, speciation, extinction and coexistence (van Doorn, Etienne)
• Ecosystem functioning: resilience and adaptive capacity in the face of (human-induced) disturbance (Berg, Eriksson, Olff, Smit)
• Community assembly: processes governing (experimental and natural) community dynamics (Etienne, Smit)
• Eco-evolutionary feedback: ecological causes and consequences of evolutionary change (Eriksson, Maan)
• Mechanistic underpinnings of evolutionary change: evolutionary causes and consequences of alternative genetic architectures and phenotypic plasticity (van Doorn, Fontaine)
• Timescales of evolutionary change (Both, Olff)
• Evolutionary systems biology (van Doorn)
• Zernike Ecology Project (Both, Dietz, Maan, Smit)

Coordinators:

Martine Maan, Chris Smit

Associated staff:

Christiaan Both, Klemens Eriksson, Rampal Etienne, Han Olff, Sander van Doorn

Evolutionary medicine is a fast growing research field within the life sciences that applies modern evolutionary theory to the study of health and disease. It aims to understand not only how people become sick (based on molecular, physiological and neurobiological mechanisms), but why people become sick, based on our evolutionary history and general evolutionary principles. Evolutionary Medicine uses key concepts in evolutionary research, such as trade-offs between different optimal solutions, host-parasite coevolution, life history theory, different modes of Darwinian selection, and the limits to adaptation, both in the past and in our current rapidly changing world. The field has yielded important progress on the understanding and treatment of cancer, infectious diseases and common environmentally dependant diseases, and also has great potential for understanding other aspects of human biology including ageing, the microbiome, vulnerability to infections, immunology, cardio-metabolic diseases and psychological disorders.

At GELIFES we run a BSc course in Evolutionary Medicine and an MSc Integrative Biology track with a profile in Evolutionary Medicine.

Researchers: Frank Chan, Gertjan van Dijk, Hannah Dugdale, Yagmur Erten, Niki Gervais, Felicity Jones, Sebastian Lequime, Simon Verhulst, Marjon de Vos

Studying women’s health in biology involves a multidisciplinary approach that integrates knowledge from genetics, endocrinology, physiology, neurobiology, behavioural biology, ecology, and evolution . Our institute integrates several research lines and approaches to study how women’s health can be improved across the lifespan. Researchers connected to this key thematic area are mentioned below.

The pregnancy period

Sleep problems are common during pregnancy due to physiological, hormonal, and psychological changes. These disturbances can significantly increase the risk of depression by disrupting mood regulation, cognitive functioning, and stress responses. Moreover, sleep disturbances during pregnancy may contribute to postpartum depression, with critical implications for both maternal and foetal health. Effectively managing maternal health during and after pregnancy requires an interdisciplinary approach that integrates behavioural neuroscience, neurobiology, immunology, and medical interventions, ensuring the well-being of both mother and baby.

Peter Meerlo focuses on the neurobiological consequences of disrupted sleep and its relationship with psychiatric disorders. Notably, 20% of pregnant women experience depressive symptoms, and 5% require treatment with antidepressants. Selective serotonin reuptake inhibitors (SSRIs) are the most commonly prescribed antidepressants during pregnancy. While SSRIs prevent serotonin (5-HT) reuptake and increase extracellular levels of 5-HT, which plays a crucial role in neurodevelopment and serves as a key neurotrophic factor, their use during pregnancy can have adverse effects on both mothers and their children. However, the precise ways in which maternal SSRI use interacts with other physiological factors to influence maternal health and neurodevelopment in offspring remain poorly understood. Jocelien Olivier investigates the effect of maternal depression on both mothers and their offspring. Her research emphasizes behavioural changes, gene alterations in the brain, and the role of the maternal microbiome in influencing offspring behaviour and brain development.

Healthy nutrition for mothers and offspring is also of great importance. Women differ from men with respect to dietary requirements and their sensitivities to develop energy balance disorders, for example when exposed to an industrialized “western-style diet”. These differences are a.o. related to the fact that women are childbearing individuals, which - besides having several anatomical specificities and functions – also rely on specific metabolic, physiological and behavioral processes required for fetal and postnatal development of the offspring. Gertjan van Dijk currently studies consequences of changes in dietary fat content, and in particular the polyunsaturated fatty acids (PUFAs) of the n-3 and n-6 type, on the short and long term regulation of energy balance and cognitive and affective functioning in the mother as well as in their female and male offspring. These studies give important clues about the current dietary recommendations regarding healthy nutrition for women and their offspring.

The menopausal period

Menopause is characterized by a decline in ovarian function, leading to reduced levels of key hormones, particularly oestrogen and progesterone, which have neuroprotective properties and support brain health. During menopause, the loss of these hormones can disrupt these neuroprotective mechanisms, increasing the vulnerability of the brain to neurodegenerative diseases like Alzheimer’s. Women are nearly twice as likely as men to develop Alzheimer’s disease, with hormonal changes during menopause believed to play a significant role. The decline in oestrogen may accelerate pathological processes, such as the accumulation of beta-amyloid plaques and tau tangles, which are hallmarks of Alzheimer’s. The interplay between menopause, hormones, and Alzheimer’s highlights the importance of early interventions and individualized strategies to protect cognitive health in women. Research by Niki Gervais has shown important consequences of mid-life ovarian hormone loss on cognition, sleep, and the brain. Currently her research is trying to understand how female biology contributes to greater vulnerability to Alzheimer's disease. Specifically, she is identifying how female sex hormones and X-linked genes contribute to the pathogenesis of this disease, focusing on how they exacerbate the adverse effects of known risk factors, including sleep disturbances and neuroinflammation.

Senescence

One of the most profound challenges we all face is that we deteriorate with age – a process known as senescence. Individuals clearly senesce differently, but our understanding of how and why individuals senesce in such different ways remains limited. Senescence differs significantly between women and men. These differences arise due to genetic, hormonal, and environmental factors, leading to variations in aging patterns, disease risks, and longevity. The hormone oestrogen has anti-inflammatory and antioxidant properties that protect against cellular damage and promote DNA repair. Oestrogen also supports cardiovascular health by maintaining arterial flexibility and reducing atherosclerosis risk. This may protect the women, however, after menopause, the decline in oestrogen accelerates aging-related processes in women, including bone density loss, increased cardiovascular risk, and cognitive changes. While women tend to age more slowly and live longer, they face unique challenges, particularly after menopause. Understanding differences between individuals is essential for developing targeted strategies to promote healthy aging. Research of Hannah Dugdale takes a comprehensive and integrative approach to investigate why individual variation in senescence evolved and is maintained. This will generate vital knowledge on how individuals can live longer, healthier lives.

Urinary tract infections

The prevalence of urinary tract infections is much higher in women than men due to anatomical differences. The female urethra is much shorter, making it easier for bacteria to travel to the bladder. Hormones play a role in increasing the risks for urinary tract infections as well. For instance during pregnancy hormonal changes and pressure on the bladder increase the risk for UTIs, but also declining oestrogen levels during menopause can lead to changes in the urinary tract, making older women more susceptible to infections. Especially in younger women UTIs are often associated with sexual intercourse. UTIs are a critical research area in women’s health due to their high prevalence and potential complications. Studying UTIs with a broader context of women’s health helps address prevention, management, and treatment strategies tailored specifically for women. Marjon de Vos focusses on antibiotic resistance, the role of the microbiome, and ecological and evolutionary processes in (infectious) microbial communities.

Cancer

Cancer is pervasive in multicellular organisms. Breakdown of regulatory mechanisms that ensure the division of labour between the cells can lead to uncontrolled cell divisions and result in cancer. Body size and longevity typically correlate with the number of cell divisions in an individual, however there is no strong association between cancer risk and these two life history traits across species. This can be explained by selection for cancer suppression mechanisms that match the species life history and delay cancer risk sufficiently for maximal reproductive success. Within species, however, cancer defences vary less than between species, which can result in sex-differences in cancer risk if the sexes differ in other traits, such as body size. On the flip side, sexual conflict can also extend to traits related to cancer risk and suppression, if the two sexes have differing trait optima. In humans, evidence suggests that cancer risk increases with body size, which can partially explain why in the majority of cancer types, the incidence is higher in men compared to women, the former being larger in body size, on average. Humans also experience an evolutionary mismatch between their evolved level of cancer suppression and current cancer risk, and the increase in reproductive cancer incidence in women strongly relates to this mismatch. This mismatch is due to not only environmental risk factors (e.g. chemical carcinogens), but also the recent changes that affected human life history (e.g. longer lifespans, larger bodies, and changes in reproductive behaviour). Yagmur Erten takes an ecological and evolutionary approach to studying cancer, taking species and sex differences in life history, cancer risk and incidence into account. Looking at cancer through the lens of ecology and evolution, we can better understand the past and present mechanisms that affect cancer risk across species and in different sexes.

Biological rhythms

Biological rhythms differ between men and women. Roelof Hut focuses on studying the causes and consequences of these differences that will help to understand their biomedical implications. For instance, earlier sleep timing in women may be the result of endocrinological effects on body temperature and its effect on sleep homeostasis. Understanding these mechanisms may help to understand sleep problems in women. In addition, evolutionary theory would predict major sex differences in response to ecological challenges like food shortage. The large investment in time and energy that mothers devote to their offspring would predict more prudent behaviour in females. During food shortage, males can show flexible sleep timing and risk-taking behaviour to avoid increasing foraging effort. Females were more prudent and rigid in sleep timing, but were also willing to invest much more time and energy to obtain food. Understanding this fundamental sex difference in basic life properties has led to understanding women specific syndromes like Relative Energy Deficiency syndrome in sports (REDs) and provided a new animal model to study the direct consequences of athletic performance on reproduction in women.