It is often assumed that biological evolution will inevitably lead, through the process of natural selection, to an optimal design for each ecological function. However, the adaptation process may be impeded or slowed down by constraints or trade-offs, obscuring the relationship between form and function. In theory, the adaptation process involves four stages: genetic variation may lead to variation in design which in turn may cause differences in performance for a given function, ultimately causing differential fitness (survival/reproductive success). Constraints may operate on all relationships between the stages. Here we propose an integrated and experimental study of the complete adaptation process that tackles all stages and relationships in three model species for a single function, locomotion. Locomotion is ecologically relevant since it is essential for many biological processes such as feeding, escaping from predators and dispersal. Performance can be easily quantified in terms of speed, acceleration, endurance and manoeuvrability. The model species are an insect, an amphibian and a reptile. Locomotory performance of these ectothermic animals is strongly temperature-dependent. Temperature is used as a model for the importance of fluctuating environmental parameters in evolution. The role of trade-offs in adaptation is investigated by considering interactions between different locomotory components,
such as speed vs. endurance. The specific research questions are the following: (1) - What is the variation in performance? Do trade-offs exist? How does temperature influence performance? (2) - What are the mechanistic causes of variation in performance (morphological, physiological, kinematic)? (3) - Is some of the variation in performance genetically determined? (4) How does variation in performance translate to differences in survival or reproductive success? To answer these questions, the three model species will be raised in the laboratory under different temperature regimes, and performance for several locomotory components will be measured and may be followed throughout development. This is mainly done by digitization of high-speed video registrations of moving test animals and numerical
analysis of the quantitative data. The obtained data on variation in performance can be correlated to parameters of design, resulting from morphometric, morphological and kinesiological research. The importance of genetic variation is assessed by measuring performance and design parameters in individuals with known relatedness (parent/offspring, sibs, half-sibs) obtained from breeding experiments (quantitative genetics). The question whether variation in performance also implies variation in fitness, is determined by comparing survival chances in laboratory or field conditions with a given predator pressure (better performing individuals are expected to have a higher chance to escape), by measuring pairing success or by directly counting the number of offspring.
To achieve this research programme, the competence and expertise of three research groups of the UIA are joined. The laboratories of Functional Morphology, Ethology and Animal Ecology each have experience in research on particular aspects of the general scheme, have broad experience with research on, and raising of, model species, and most of the required facilities are present. The requested budget includes only incubators for temperature-controlled breeding experiments. The very labour-intensive nature of most of the research aspects involved in this proposal, explains why most of the requested budget is reserved for taking on additional scientific and technical personnel.