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10 Cards in this Set
- Front
- Back
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Demographic Stochasticity |
Death sequence of birth and deaths in small populations that can add variability to a small population. |
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Environmental Stochasticity |
Seemingly random variability in resource availability, ecology community composition, predation pressure, weather events, etc that cause fluctuations in a population growth rate. Can effect both small and large populations to the point of extinction. |
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Population dynamics |
The seemingly random events caused by environmental changes that influence how a population changes in size through time. |
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Chaotic population fluctuations |
Occur only when environmental or demographic conditions change. |
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Lack and Life History |
Lack argued that environmental variability (differences in day length) was the driving force behind the evolution of clutch size variability, with the ideal clutch size for a species being that which maximizes fitness in its local environment.The penalty for laying too many eggs in bad years is greater than the benefit of laying a few more eggs in good years. |
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Birth rate formula |
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High vs Low birth rates |
Having a high birth rate vs. a low birth rate doesn't mean a species' strategy is better or worse. Different life histories can succeed within the same environmental conditions. |
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Age structure |
Age structure characterizes the distribution of ages within a population.High birth and death rates lead to age structures with many more young than old individuals. Low birth and death rates lead to more uniform age structures. |
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Fecundity |
The average number of offspring per reproductive female per unit time. |
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Life History |
A successful life history produces stable or growing populations. |
