Module Information

The module starts with a review of the concept of environmental animal physiology or eco-physiology in context with more classical comparative animal physiology that often incorporates organ systems approaches within extreme animals without taking an evolutionary perspective. Environmental independent changes (development & periodic biological clocks) will be also highlighted. Evolutionary change will be described in terms of irreversible change within genotype and phenotype in populations and generations. The concept of adaptation will be reviewed: trait selected for by natural selection, controversy, when it is real, is it optimal, and are all physiological traits adaptive. This will lead to a description of non-adaptive evolution, pleoitropy, phylogenetic inertia, founder effect, and genetic drift. Methods to measure adaptation will be discussed (comparative, mutants, knockouts, phylogenetic reconstruction, genetic cline analysis). The mechanism of adaptation (molecular level) will be resolved, as also the relative importance of behaviour and selection in a fully functional animal. Fixed genotypes, long-term change will be explored with respect to phenotypic plasticity in individuals, and the terms acclimatization and acclimation and the potential for phenotypic plasticity to be adaptive will be assessed. Throughput the module references will be made to the influence environmental change and modern human populations on the physiology of other animals
The aquatic block of lectures starts with an examination of the physiological adaptations for invertebrate marine life living within sea water, arguably the most trouble-free stable environment for animals on the planet. The lectures progress onto marine vertebrates (Myxiniformes, Chondrichthyes and teleosts), then moves to deal with brackish water, and on into the freshwater environment from both an invertebrate and vertebrate perspective. After which, the thermal adaptation of aquatic organisms within a variety of habitats is discussed, covering the open ocean, polar regions, intertidal etc. Specialised topics, such as regional endothermy are also discussed. Locomotion within the aquatic environment is governed by organism size and Reynolds forces; the lectures will discuss swimming in relation to viscosity and inertia, across a range of aquatic organisms both invertebrate and vertebrate. The cheap alternative to swimming employed by many aquatic invertebrates, employing buoyancy and increased drag, will also be investigated. Leading on from movement in the aquatic environment, the lectures will then deal with the subject of feeding and respiration. The subject matter will investigate the different methods employed by aquatic organisms, including air breathers, and the problems they face relative to their body size. The transmission of sound and light in water differs from those in air. The adaptation of sensory modalities in aquatic organisms will be reviewed. These will include vision and light production, sound production and reception, electroreception and mechanoreception. In addition chemical communication (Pheromones/kairomones) will be covered. Aquatic organisms are subjected to the monotonous daily cycling of light and dark or the ebb and flow of tidal cycles. Most possess internal ‘biological clocks’ that enable them to cordinate their behaviour and physiology to maximise fitness. This module will describe, using appropriate examples, the physiological basis of biological clocks and how they influence behaviour to suit prevailing environmental conditions. The module will also investigate the phenomenon of electricity generation and communication in aquatic vertebrates. The final topic in the aquatic section will cover the physiological and behavioural adaptations to extreme aquatic habitats, for example transient water bodies, osmotically peculiar habitats and thermally extreme waters such as deep-sea vents and hot springs.