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31 Cards in this Set
- Front
- Back
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Darwin's Natural Selection, 5 basic tenets:
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1.) Individuals vary within populations
2.) Exponential increase of organisms 3.) Struggle for existence 4.) Differential survival and reproduction among individuals 5.) Descent to next generation |
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Define: Continuous Variation
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-Hard to make discrete categories
-Naturalists/Biometricians ex: Height in humans |
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Define: Discontinuous Variation
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-Should see discrete categories
-Mendelians ex: Hair color |
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Why is blending inheritance false?
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There would eventually not be any evolutionary change if half of the genes of the mother and father are given to the offspring. Solution: Mendelian Genetics
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Define Mendelian Genetics
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Knowledge that for every trait both a dominant and recessive allele exist to be expressed.
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2 Main Goals of Evolutionary biology?
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Analyze history of life
and determine causes and mechanisms. |
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Who was the first to study the evolution of organisms by creating a linear chain?
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Lamarck
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Define: Hardy Weinberg Principle
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Variations are maintained across generations.
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What is the ultimate source of variation?
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Mutation.
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Natural Selection uses _____ to mold organisms.
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Mutation
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What are the present day principles?
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1.) Selection acts on individuals
2.) Evolution is not goal - oriented 3.) Evolution is fortuitous 4.) Evolution favors individual traits - "we live in a selfish world" |
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Define Evolution.
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Change over generations in the population of individuals differing genetically in one or more traits.
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What happens if the observed does not equal what you expected?
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-Something affecting mating probabilities
-Violated assumptions of model (figure out what assumption was violated) |
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What are the five HWE assumptions?
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1.) Mating is random
2.) No Natural Selection 3.) No Mutation 4.) No differential gene flow 5.) Populations are infinitely large - no drift |
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Define: INTRA-specific
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~"With Species"
-mating -competition for resources -cooperation |
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Define: INTER-specific
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~"Between Species" (think Intercept)
-competition/predation -parasitism/mutualism |
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When you look at a graph and it's "stabilizing selection", what does that tell you? (normal bellcurve)
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-Mean is unchanged
-Variance is reduced |
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When you look at a graph and it's "directional selection", what does that tell you? (skewed to the right)
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-Mean is changed
-Variance is changed |
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When you look at a graph and it's "disruptive selection", what does that tell you? (two small curves)
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-Mean may change
-Variance increased |
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What are the three rates of selection?
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-Value of s
-Allele frequency -Dominance Effect |
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Why is studying one gene not enough?
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-Many organisms have more than 5,000 genes
-More than one gene influences a trait -Genes interact -Environmental influences on gene expression |
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What is "Quantitative Genetics"?
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-Assumes multiple genes influence a trait
-Those genes can interact -Environment controls expression |
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When estimating Va, the closer the slope is to 1, what does that mean? And when the value is closer to 0, what does that mean?
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If the values are the same or highly correlated, the slope will be closer to 1. If the value is closer to 0, that means the values are less correlated.
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How would you test V_E? (Variance due to environment)?
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-Place genotype in multiple environments
-Measure phenotype -Produces the norm of reaction |
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What if you calculate the V_E (Variance due to environment), and the response IS NOT similar?
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-lose predictive ability
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What is "Fisher’s fundamental theorem of selection"?
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The rate of selection is directly proportional to the amount of additive genetic variance.
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"Selection Intensity" (i) is what?
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Change in mean relative to standard deviation.
Formula: (after-before)/sqrt(variance) |
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"Selection gradient" (b) relates to what?
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Fitness.
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The Rope Example in class proved what when it comes to selection?
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That change is an overall balance of selection and that multiple traits influence fitness.
Need to integrate each trait & correlations!! |
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What is the difference between "Linkage disequilibrium" and "pleiotrophy"?
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"Linkage disequilibrium" deals with physical location on chromosomes and "pleiotrophy" is when one gene influences multiple phenotypic traits.
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What four factors influence allele frequency?
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-Genetic Drift
-Inbreeding -Mutation -Gene Flow |
