Lecture 8: Animal Adaptations Flashcards
To maximize fitness…
An individuals response to change must be shorter than the period of change
Responses to environmental change fall in what three categories (Describe)
Developmental (Years)
- individuals alter its development to produce a phenotype most suitable to a persistent slow change in environmental conditions
2) Acclimatory (Days-Weeks)
- Changes in response to seasonal variations
3) Regulatory (seconds-minutes)
- Rapid changes in behavior or rates of physiological processes i.e. shivering
Describe desiccation Tolerance
when animals (Water bears) allow their tissues to dry up when there is not water and revitalized when water becomes available again
Describe Conformers vs regulators in terms of temperature regulation
Conformers = allow internal conditions to follow external changes
Regulators = Maintain constant internal conditions via homeostasis involving a negative feedback system
Describe poijilothermy
Animals that cannot maintain constant body temperature, mostly aquatic organisms
Describe homeothermy
Animals that maintain constant body temperature, most birds and mammals
Describe Ectotherms vs Endotherms
Ectotherms: Regulate body temperature by gaining heat from external sources
Endotherms: Regulate body temperature by the production of heat via metabolism
Most Poikilotherms are _____ whereas most homeotherms are ____
Ectotherms then endotherms
What are the advantages and disadvantages of Ectotherms
Advantage: Low energy expenditure
Disadvantage: Everything is limited by temperature fluctuations
What are the advantages and disadvantages of endotherms
Advantage: Can be active at any temperature
Disadvantage: Energy expenditure is extremely high
Animals usually die of what before they die due to direct causes of cold temperatures
starve to death
True or False; body size is one of the most important animal characteristics
True
Describe Allmetry
Surface area to volume ratio
Describe the allometric relationship
Relative increase in physical or physiological property of an organism in relation to its body size
- Body size increase = volume grows faster than surface area
- As body size changes, SA/V ratio changes
- As SA/V ratio changes, heat is lost to environmental changes
Describe the relationship between volume and heat
The larger the volume, the greater the total amount of heat is required to keep warm, but the less heat is lost through the outer surface of the organism
