Physiological Ecology Homeostasis: maintenance of a relatively stable internal state under a much...

Physiological EcologyHomeostasis: maintenance of a relatively stable internal state under a much wider range of external environmental conditions.

Temperature regulation (thermoregulation)Physiological Optima and Tolerance CurvesTolerance limits, optimaNet benefitAcclimation Lecture # 111 October 2015

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

Body Mass, grams

Log,

Rabbits

Moose

Beaver

Squirrels

Racoon

Metabolic Cost of MovementLog,

Log,

Metabolic Cost of Movement

Log,

Log,

Metabolic Cost of Movement

Log,

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 improvementdiminishes. 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

Thermoconformers

Passive thermoconformer

Nephrurus levis

Active Thermoregulator

Ctenophorus isolepis

Active Thermoregulator

Ctenophorus isolepis

Thermoconformer

Ctenotus skinks

Ctenotus leae

Ctenotus piankai