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24 Cards in this Set
- Front
- Back
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Evolution
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Two parts:
-natural selection -random genetic drift |
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Natural Selection
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the differential capacity for survival and reproduction (some organisms and species survive and reproduce better than others)
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Random Genetic Drift
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accumulation of random events that change the makeup of a gene pool slightly, but often compound over time
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Heritability
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if traits leading to the higher fitness are heritable, they will appear more in succeeding generations since these traits are selected for.
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Variability
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all species vary - members of a species vary from other members of the same species
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Differential Capacity for Survival
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the environment and the conditions under which a species lives favor some varieties over others
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Population
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the whole
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Sample
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large enough to be representative, yet small enough to be practical
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Frequency Histogram
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allows us to make qualitative analysis of data
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Normal Distribution
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bell shaped curve, high frequency of the central value
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Skewed Distribution
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has a very long tail extending toward one of the extremes
-skewed in the direction the tail points |
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Bimodal Distribution
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has two modes (or humps)
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Mean
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arithmetic average of a set of numbers
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Standard Deviation
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indicates how the data points vary around the average
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Variance
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s^2
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67-95-99% Rule
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67% of data points will fall within 1 SD
95% of data points will fall within 2 SD 99% of data points will fall within 3 SD |
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Darwinian Fitness (relative fitness)
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relative success at survival and reproduction
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Fitness Coefficient
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W
has a value between 0 and 1 (1 being most fit, 0 is lethal) |
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Selection Coefficient
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S
1 is least fit 0 is most fit |
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S = 1 - W
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they are opposites, obviously.
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founder effect
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extreme example of genetic drift. loss of genetic variation due to a small colony
bottleneck CAN cause founder effect |
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fixation
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when every individual within a population has the same allele at a particular locus
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Required for Genetic Drift:
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1. small population
2. isolated population 3. interbreeding |
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bottleneck effect
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the reduction of population's gene pool and the accompanying changes in gene frequency when a few members survive the widespread elimination of a species
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