Each Species has a range of
environmental tolerances that determines its potential geographic distrubution
The temperature of an organism is determined by
exchanges of energy with the external environment.
Organisms have two options for coping with environmental variation, which are?
Tolerance and Avoidance
Potential geographic range of a species is determined by
the physical environment
Physical environment influences an organisms ecological success in two ways?
1. Availability of energy and resources
2. Extreme conditions can exceed tolerance limits
Actual geographic distribution of a species is
Ex. Dispersal, competition, etc
related to other factors as well
* Differs from its potential Distribution
Most likely to differ bc of geologic differences
...
Terrestrial biomes are categorized on the basis of
growth forms of dominant plant species
What are good indicators of the physical enviroment?
Plants because they do not move.
* ability to tolerate the full range of env conditions
Climate envelope
range of conditions over which a species occurs.
- Acclimatization can lead to a high breathing rate
- Acclimatization and adaptation may require an investment of Energy & Resources by the organism)
Adaptation is a transgenerational
genetic response of the population
Acclimatization is
short term reversible
Ecotypes are
Populations with adaptations to unique env.
- In both Abiotic and Biotic environmental factors
Andean Pop. have high rbc concentrations
Tibetans have faster breathing rates and
and large lung capacity
higher blood flows
Internal temp. influences
- rates of all rate processes
- cell membrane fluidity
- water turnover
Organisms temp. is determined by
the balance of gains and losses of energy to the external env.
Some organisms use behavior to
control exchange of energy with the environment
Behavioral thermoregulation
predominant mechanism of temp regulation in ectotherms
Heat exchange occurs across surfaces and
relative surface area decreases as organisms get bigger
Surface area:volume ratio decreases as organisms get bigger