19 terms

Lecture 1

STUDY
PLAY

Terms in this set (...)

Homeostasis
Maintenance of a constant internal environment
Negative feedback
Control system opposes deviations from set point
Positive feedback
Control system reinforces deviations from set point
Acclimation
New and old environments differ in just a few ways (a lab phenomenon)
Acclimatisation
New and old environments differ in numerous ways, e.g. winter and summer, high and low altitude
Phenotypic plasticity
Expression of different genotypes to form different phenotypes in different conditions
Evolutionary convergence reflects...
different species' adaptations to a similar environmental challenge
As animals increase in size...
• Their skeletons must be proportionately larger to support their mass
• Muscles required for locomotion must represent an ever larger fraction of body mass
The lowest temperature sea water is liquid
-1.9°C
Animals survive in cold seawater through...
• More robust proteins
• Anti-freezes in circulation
Desert iguanas can survive tissue temperatures as high as...
48.5°C
Oxygen is so important because...
Allows ETC as it acts as the final electron acceptor
Suitability of environments often depends on oxygen supply; challenges at...
• High altitudes - lower pp of oxygen
• In water - not very soluble, local depletion by microbes
Water
Universal solvent, threat of desiccation, some terrestrial animals have evolved exceptional tolerance of water loss, animals often modify their own environments
Evolution
Change in gene frequencies over time within a population of organisms
A trait is an adaptation if...
It has come to be present at a high frequency in a population because it enhances fitness
Mechanisms
Components and workings, i.e. physiology PROXIMATE
Knowledge of a physiological mechanism...
Doesn't imply knowledge of adaptive significance
Origins
Mechanisms of the products of evolution, i.e. light production by fireflies ULTIMATE