IAP-25-008

Exploring how plasticity and morphology shape life history strategies in ectotherms

Life history strategies—how organisms allocate energy to growth, survival, and reproduction—are shaped by trade-offs that reflect both ecological conditions and evolutionary constraints (Gaillard et al. 1989). These strategies are often interpreted through the lens of the pace-of-life (POL) continuum, which spans from fast (early reproduction, short lifespan) to slow (delayed reproduction, long lifespan) life histories (Gaillard et al. 2016). The pace-of-life syndrome (POLS) further integrates behavioural and physiological traits into this framework, suggesting co-evolution of life history, behaviour and physiology (Wright et al. 2019).

However, recent work shows that these frameworks oversimplify the complex dynamics of energy acquisition and allocation, and often ignore the roles of developmental plasticity and morphological traits (Dixon & Smallegange 2025; Lucas et al. 2025; Smallegange & Guenther 2025). This project will take a novel, integrative approach to understanding life history strategies by explicitly incorporating plasticity and morphology into POL and POLS frameworks.

The project will focus on ectothermic animals, whose life history strategies are particularly sensitive to environmental conditions such as temperature and food availability (Atkinson & Sibly 1997). Ectotherms also exhibit high levels of plasticity and morphological diversity, making them ideal models for testing how environmental variation shapes life history evolution (Smallegange et al. 2025; Stevenson et al. 2025).

We will explore how plastic responses to environmental conditions and morphological traits influence life history strategies across ectothermic taxa. By combining meta-analyses, comparative analyses and computational modelling, we aim to uncover the ecological and evolutionary mechanisms that shape life history variation and predict species’ responses to environmental change (Figure 1).

The project will be structured around four work packages (WPs), each leading to a scientific publication:

• Paper 1 (Meta-analysis): A global synthesis of how plasticity in energy acquisition and allocation affects life history traits in ectothermic animals. This will identify key patterns and gaps in current understanding, and inform the design of subsequent empirical and modelling work.

• Paper 2 (Morphology × Plasticity): Building on existing work showing that morphology predicts life history strategies in ectotherms (e.g., fish), this study will test whether food-induced plasticity alters these relationships. Using comparative datasets, we will assess whether morphological predictors remain robust across environmental contexts, and whether plasticity mediates or modifies these associations.

• Paper 3 (Computational Modelling): A fully computational project using Dynamic Energy Budget–Integral Projection Models (DEB-IPMs) (Smallegange & Lucas 2024) to simulate how plasticity and morphology interact to shape life history strategies in ectotherms under varying ecological scenarios (e.g., food availability, temperature, density). This will allow us to explore evolutionary trajectories and demographic consequences of different trait combinations.

• Paper 4 (Predictive Testing): We will test whether life history strategies—and their plastic and morphological components—predict species’ vulnerability or resilience. This will involve:
• Correlating life history traits with IUCN (International Union for Conservation of Nature) Red List conservation status.
• Testing model predictions against documented conservation interventions in ectothermic species (e.g., amphibians, reptiles, fish).
• Evaluating whether incorporating plasticity and morphology improves predictive accuracy for conservation outcomes.

Year 1

– Conduct meta-analysis (Paper 1)
– Start writing Paper 1
– Begin data compilation for Paper 2

Year 2

– Complete Paper 2 (Morphology × Plasticity)
– Develop and run DEB-IPMs for Paper 3
– Present findings at national conference
– Finalise Paper 1; draft Paper 2

Year 3

– Complete Paper 3 (Computational modelling)
– Begin Paper 4 (Predictive testing)
– Draft Papers 3 and 4

Year 3.5

Submit all papers to peer-reviewed journals
– Present findings at international conference
– Complete and submit thesis

The student will gain expertise in:
• Meta-analysis and comparative methods
• Morphometric and demographic modelling
• Computational modelling
• Statistical analysis (e.g., GLMMs, PCA, phylogenetic corrections)
• Conservation data analysis (e.g., IUCN Red List, intervention case studies)
• Scientific writing and communication

They should have a background in evolutionary ecology, life history theory, or population biology and an interest in both empirical and theoretical approaches. Training in relevant software and methods will be provided throughout the studentship.