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Definition
| the evolution of two or more species that interact closely with one another, with each species adapting to changes in the other; specific and reciprocal |
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Term
| individual optimization hypothesis |
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Definition
| that each individual in a population has its own optimal clutch size, so that not all individuals are identical |
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Definition
| the clutch size at which productivity is maximal for the population |
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Term
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Definition
| that clutch size in birds is determined by the number of young that parents can provide with food |
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Term
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Definition
| the theory that natural selection will maximize reproductive rate, subject to the constraints imposed by feeding and predator avoidance |
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Term
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Definition
| the process in nature by which only the organisms best adapted to their environment tend to survive and transmit their genetic characteristics to succeeding generations while those less adapted tend to be eliminated |
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Term
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Definition
| models that assume natural selection will achieve adaptations that are best possible for each trait in terms of survival and reproduction;help us think about what costs/benefits are for an ecological strategy |
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Term
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Definition
| the observable physical characteristics of an organism |
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Term
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Definition
| how a particular trait is regulated by an individual in a physiological or biochemical matter |
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Term
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Definition
| the evolutionary reason for an adaptation or why a trait is maintained in a population; opposite of proximate factors |
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Term
Steps Natural Selection operates through
(there are 6) |
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Definition
1. genetic variation occurs; individuals are not identical
2. more offspring produced that can survive
3. survival of the fittest
4. organisms are selected for their survival characteristics known as natural selection
5. selection drives genetic change (evolution)
6. evolution occurs at the population level, the individual does not change |
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Term
directional selection
(most typical) |
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Definition
| phenotypes at one extreme are selected against |
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Term
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Definition
| phenotypes near the mean of the population are fitter than those at either extreme, thus, the population mean value does not change |
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Term
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Definition
| the extremes are favored over the mean |
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Term
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Definition
| lay a given number of eggs, no matter what |
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Term
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Definition
| they will continue to lay eggs until the nest is "full" |
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Term
| example of allopatric (geographic) speciation |
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Definition
| Finches with geographic isolation |
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Term
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Definition
| the individual contribution of an organism to the next generation. Darwanian fitness is the measure of how many offspring survive and reproduce in the next generation. This is a measurable item in evolution but is NOT absolute, measured across species, short term and individual traits |
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Term
| units of natural selection |
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Definition
individual:survival and reproduction by individuals
gametic: selection operates on eggs and sperm
kin: selection favors survival of relatives- behavior
group: individual survival is not as important as group survival |
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