Lecture 3: Physiological ecology: animals Flashcards
Animals that live in cold places tolerate which type of temperatures?Animals that live in warm places tolerate which type of temperatures?
Animals that live in cold places tolerate colder temperatures and animals that live in warm places tolerate warmer temperatures
Latitude definition
Distance away from the equator
Why have mechanism of Homeostasis evolved?
To challenge hostile environments
What is required to maintain homeostasis?
Energy
What is homeostasis limited by?
Constraints and trade offs
Surface area and volume ratio meaning of each
Surface area determines equilibrium rate
Volume determine inertia
Bergman’s rule
Homeotherms tend to be bigger at higher latitudes (colder weather) to conserve heat
Allen’s rule
Homeotherns tend to have smaller appendages or shorter and thicker limbs at higher latitudes (colder weather) to better conserve heat
What is Insulation with fur/fat/feathers more important than and why?
Size and shape
Helps arm blooded animals keep their warmth
Why are arteries and veins appressed in appendages?
To conserve heat
Evaporative cooling
Water evaporates (liquid become vapour) so the air around it cools down
Behavioural thermal regulation
The maintenance of a constant body temperature by means of basking, sheltering, shivering
What are phenotypes of organisms riddled with?
Compromises dictated by trade offs
Two reason why natural selection produced deeply imperfect organism
Trade offs
Constraints
What are tradeoffs
when a beneficial change in one trait is linked to a detrimental change in another trait
What is an example of a trade off for a weasel
Weasels live in cold temperatures however they’ve traded off being bigger to conserve warmth for being able to catch prey faster because of their skinny bodies
What does constraint mean in biology?
Selection build on what already there
In other words it does no redesign attributes of an organism but rather enhances it
What are the optimal conditions for a reaction to occur best?
Optimal temperature and osmotic conditions
What are organisms like?
Complex chemical reactions
What is the idea that similar environments lead to similar adaptations called?
Convergent evolution
What type of temperature do temperate animals withstand
Colder temperatures
What is seasonality of temperature like near the equator?
Low
What are poikilotherms?
Organism that lack the psychological means to deviate from their environment
What are homeotherms?
Organism that must regulate heat balance to keep an internal temperature close to the environments
What are the energy requirements of poikilotherms compared to homeotherms?
Because maintaining a constant internal temperature requires more energy, poikilotherms have a lower energy requirements than similarly sized homeotherms
What is radiation?
Heat transfer by electromagnetic radiation
What is conduction?
Transfer of heat by direct contact with substrate
What is convection?
Heat transfer mediated by moving fluid
