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19 Cards in this Set
- Front
- Back
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How many millions of years ago was the origin of Earth? |
4.6million years ago |
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Vascular plants formed extensive forests duringwhich period? |
Carbiniferous |
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What is a population? |
A group of individuals living in a particular place. |
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What is a species? |
A group of populations whose individuals may be able to breed with each other |
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What is a gene? |
A section of DNA that carries information for producing specific traits |
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What is an allele? |
Different forms of a gene |
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What does homozygous mean? |
Having the same alleles for a given trait (PP,pp) |
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What does heterozygous mean? |
Having different alleles for a given trait (Pp) |
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What are two types of evolution? |
Macroevolution and microevolution |
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What is evolution? |
Change in allele (or genotype) frequencies over generations |
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What is the Hardy-Weinberg Law? |
An equation that allows us to predict gene and genotype frquencies in population - that isn't evolving. It states that allele frequencies will not change from one generation to the next, if certain assumptions are met. |
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What are the assumptions of the Hardy-Weinberg Law? |
- Mating is random across the entire population - All genotypes have equal viability and fertility (no selection for or against genotype) - Migration into the population can be ignored - Mutation does not occur, or is so rare it can be ignored - Population is large enough that the allele frequencies do not change from generation to generation - Allele frequencies are the same in females and males |
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What are some forces that cause deviation from the Hardy-Weinberg Law (evolution)? |
- Non-random mating - Gene Flow (migration) - Mutation - Natural selection - Genetic Drift |
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Does Natural Selection work on heritable variations, acquired traits, or both? |
Natural selection only works on heritable variations |
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Regarding Natural Selection, what are variations produced by? |
Natural selection can only work with what's given. Variations are produced by different genetic mechanisms (e.g. mutation, sexual reproduction, recombination) |
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What is Natural Selection working towards? |
A Natural Selection is situational to a given environment in a given time and place. There is no ideal organism. |
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What is the Chi Square Test? |
A hypothesis tool for testing if there is no change in allele frequencies from one generation to the next. If your Chi Square calculated value is greater than the Chi Square critical value in the appropriate cell, then you reject your hypothesis that there is no change in allele frequency. |
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What is the importance of the Hardy-Weinberg Law? |
If assumptions are met, we can use it to estimate allele and genotypic frequencies that would otherwise be difficult to measure. If assumptions are not met (can be tested statistically), then we know that some outside force is perturbing allele or genotype frequencies. |
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What is the Bottleneck Effect? |
The bottleneck effect occurs when a population undergoes a drastic reduction in size - often associated with some catastrophic event. The survivors are not representative of the original gene pool. |
