Physiological Ecology Homeostasis: maintenance of a relatively stable internal state under a much wider range of external environmental conditions Temperature regulation (thermoregulation) Also osmoregulation Physiological Optima and Tolerance Curves Acclimation Methane Emergency!:

Energetics of Metabolism and Movement Ingestion = Assimilation + Egestion Assimilation = Productivity + Respiration Productivity = Growth + Reproduction Ingestion = Egestion + {Respiration + Growth + Reproduction} {Assimilation} Homeotherm versus Poikilotherm Endotherm versus Ectotherm

Log, Body Mass, grams Log,

Metabolic Cost of Movement Log,

Metabolic Cost of Movement Log,

Metabolic Cost of Movement Log,

Adaptation and Deterioration of Environment Non-directed (random) changes in either A or B are equally likely to reduce the level of adaptation (d ) when small, but as the magnitude of undirected change increases, the probability of improvement diminishes. Duality of Fisher ’ s model (A and B can be interchanged) Ronald A. Fisher

Water Economy in Desert Organisms Other Limiting Materials Sensory Capacities and Environmental Cues Adaptive Suites Design Constraints

Heat Budgets and Thermal Ecology

Passive thermoconformer Nephrurus levis

Active Thermoregulator Ctenophorus isolepis

Active Thermoregulator Ctenophorus isolepis Thermoconformer

Ctenotus leae Ctenotus piankai

Australian Ctenotus skinks

Australian skink: Ctenotus brooksi

Australian skink: Ctenotus leae

Australian skinks: Ctenotus piankai and Ctenotus helenae

Phrynosoma asio (Mexico)

Phrynosoma Antipredator Blood Squirting

Ecological Equivalent Thorny Devil Moloch horridus (Australia)

Phrynosoma platyrhinos

Ctenotus leae Ctenotus piankai

Moloch Phrynosoma Ctenotus piankai Ctenotus leae Slope