Do now activity #3 What is the difference between a variation & adaptation? Give an example of each. What is the difference between single and polygenic traits? True/False: Dominant traits always have a high relative frequency. If #3 was incorrect, please correct it to form an accurate statement.

Section 6-2: Gene frequency Essential Question: How can the environment impact relative (gene/allele) frequency? Support your explanation with an example. Learning Target Justify why an advantageous trait will increase in proportion from one generation to another when provided statistical evidence. Use data to explain how change in gene frequency caused by natural selection is related to environmental factors such as seasonal temperature, climate change, acidity, light, geographic barriers, & evolution of other organisms. Section 6-2: Gene frequency

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Relative (gene/allele) overview ____ _____ is the number of times an allele occurs in the gene pool. Relative (gene/allele) frequency Relative Frequency Evolution (genetic terms): any change in the relative frequency of alleles in a population

overview Genetic drift is a random change in relative frequency because of chance.

In small populations, there can be more or less of an allele just by chance. Examples: Natural disasters Alleles passed on are random overview Remember, the smaller the group the less likely it will reflect the laws of probability Ex: coin toss

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Natural selection ICE AGE Directional Selection can be caused when nature is against one end of variation. Example: ICE AGE

Natural selection DROUGHT Stabilizing Selection can be caused when nature is against both ends of variation. Example: DROUGHT

Disruptive Selection can be caused when nature is against the most common variation. Natural selection Example: BROWN FUR COAT INDUSTRY

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Founder effect Founder effect is when relative frequencies change because a small group of the population moves away. The new place has… a) MORE VARIATION b) LESS VARIATION c) SAME AMOUNT OF VARIATION cyclins The new island has… a) MORE VARIATION b) LESS VARIATION c) SAME AMOUNT OF VARIATION

Founder effect If, by chance, an individual with a specific allele can reproduce a lot, then there will be more of the allele in the population. cyclins

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Sample of Original Population examples Sample of Original Population

Sample of Original Population examples Founding Population A Sample of Original Population Founding Population B

Sample of Original Population The new place has… a) MORE VARIATION b) LESS VARIATION c) SAME AMOUNT OF VARIATION examples Founding Population A Sample of Original Population Descendants Founding Population B

Do now activity #4 How is the picture an example of genetic drift? How is the picture an example of Founders Effect? Genetic drift because the relative frequency changed from mutation at 4.5% to 20% to 41% (Total is 22) because of earthquake/death/etc. Founders because Small group moved away so relative frequency of original population went from 4.5% to 0% mutation