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![Page 1: Analyze and evaluate the effects of other evolutionary mechanisms, including genetic drift, gene flow, mutation, and recombination. Unit 11 7F.](https://reader035.fdocuments.net/reader035/viewer/2022062718/56649e865503460f94b89293/html5/thumbnails/1.jpg)
Analyze and evaluate the effects of other evolutionary mechanisms, including genetic drift, gene flow, mutation, and recombination.
Unit 117F
![Page 2: Analyze and evaluate the effects of other evolutionary mechanisms, including genetic drift, gene flow, mutation, and recombination. Unit 11 7F.](https://reader035.fdocuments.net/reader035/viewer/2022062718/56649e865503460f94b89293/html5/thumbnails/2.jpg)
Let’s remember…
• An allele is an alternative form of one gene
B stands for black b stands for brown
The allele would be…
![Page 3: Analyze and evaluate the effects of other evolutionary mechanisms, including genetic drift, gene flow, mutation, and recombination. Unit 11 7F.](https://reader035.fdocuments.net/reader035/viewer/2022062718/56649e865503460f94b89293/html5/thumbnails/3.jpg)
Genetic Drift
• An evolutionary mechanism in which allele frequencies change in a population
![Page 4: Analyze and evaluate the effects of other evolutionary mechanisms, including genetic drift, gene flow, mutation, and recombination. Unit 11 7F.](https://reader035.fdocuments.net/reader035/viewer/2022062718/56649e865503460f94b89293/html5/thumbnails/4.jpg)
Allele frequency changes due to…
• Natural disaster like flood, fire, or earthquake• A random change of the
population (some are eliminated)• Different from natural selection
b/c its by chance or randomly
![Page 5: Analyze and evaluate the effects of other evolutionary mechanisms, including genetic drift, gene flow, mutation, and recombination. Unit 11 7F.](https://reader035.fdocuments.net/reader035/viewer/2022062718/56649e865503460f94b89293/html5/thumbnails/5.jpg)
Original Pop
R = red star r = green heart
Pop after change
6R, 5r 5r
![Page 8: Analyze and evaluate the effects of other evolutionary mechanisms, including genetic drift, gene flow, mutation, and recombination. Unit 11 7F.](https://reader035.fdocuments.net/reader035/viewer/2022062718/56649e865503460f94b89293/html5/thumbnails/8.jpg)
Bottleneck Effect
• The change in allele frequency where only genes of the surviving population members can be passed to future generations
![Page 11: Analyze and evaluate the effects of other evolutionary mechanisms, including genetic drift, gene flow, mutation, and recombination. Unit 11 7F.](https://reader035.fdocuments.net/reader035/viewer/2022062718/56649e865503460f94b89293/html5/thumbnails/11.jpg)
Gene Pool
• the sum of all the genes in an interbreeding population
![Page 12: Analyze and evaluate the effects of other evolutionary mechanisms, including genetic drift, gene flow, mutation, and recombination. Unit 11 7F.](https://reader035.fdocuments.net/reader035/viewer/2022062718/56649e865503460f94b89293/html5/thumbnails/12.jpg)
Gene Pool
• 2 blue alleles• 1 red allele• 12 green alleles
![Page 14: Analyze and evaluate the effects of other evolutionary mechanisms, including genetic drift, gene flow, mutation, and recombination. Unit 11 7F.](https://reader035.fdocuments.net/reader035/viewer/2022062718/56649e865503460f94b89293/html5/thumbnails/14.jpg)
Founder Effect
• The change in allele frequency in a gene pool that changes from a large population to a small population• Ex: small number of individuals get
separated from a larger population… the change in the allele frequency is the founder effect
![Page 17: Analyze and evaluate the effects of other evolutionary mechanisms, including genetic drift, gene flow, mutation, and recombination. Unit 11 7F.](https://reader035.fdocuments.net/reader035/viewer/2022062718/56649e865503460f94b89293/html5/thumbnails/17.jpg)
Gene Flow
• Occurs when the genes of 1 population flow into a different population• This change causes a shift in allele
frequency
![Page 18: Analyze and evaluate the effects of other evolutionary mechanisms, including genetic drift, gene flow, mutation, and recombination. Unit 11 7F.](https://reader035.fdocuments.net/reader035/viewer/2022062718/56649e865503460f94b89293/html5/thumbnails/18.jpg)
Immigration• Alleles move INTO a population
![Page 19: Analyze and evaluate the effects of other evolutionary mechanisms, including genetic drift, gene flow, mutation, and recombination. Unit 11 7F.](https://reader035.fdocuments.net/reader035/viewer/2022062718/56649e865503460f94b89293/html5/thumbnails/19.jpg)
Emigration
• Alleles move OUT OF a population
![Page 20: Analyze and evaluate the effects of other evolutionary mechanisms, including genetic drift, gene flow, mutation, and recombination. Unit 11 7F.](https://reader035.fdocuments.net/reader035/viewer/2022062718/56649e865503460f94b89293/html5/thumbnails/20.jpg)
Lots of gene flow…
• Slows down evolution• Lots of new alleles coming into
and out of a population• More genetic variation within a
population• Makes 2 populations more similar
![Page 21: Analyze and evaluate the effects of other evolutionary mechanisms, including genetic drift, gene flow, mutation, and recombination. Unit 11 7F.](https://reader035.fdocuments.net/reader035/viewer/2022062718/56649e865503460f94b89293/html5/thumbnails/21.jpg)
![Page 22: Analyze and evaluate the effects of other evolutionary mechanisms, including genetic drift, gene flow, mutation, and recombination. Unit 11 7F.](https://reader035.fdocuments.net/reader035/viewer/2022062718/56649e865503460f94b89293/html5/thumbnails/22.jpg)
Lack of gene flow…
• Less variation within a population• Makes 2 populations more
different and separates them
![Page 23: Analyze and evaluate the effects of other evolutionary mechanisms, including genetic drift, gene flow, mutation, and recombination. Unit 11 7F.](https://reader035.fdocuments.net/reader035/viewer/2022062718/56649e865503460f94b89293/html5/thumbnails/23.jpg)
![Page 24: Analyze and evaluate the effects of other evolutionary mechanisms, including genetic drift, gene flow, mutation, and recombination. Unit 11 7F.](https://reader035.fdocuments.net/reader035/viewer/2022062718/56649e865503460f94b89293/html5/thumbnails/24.jpg)
Mutation
• Any change in the genetic material of a cell• Can occur within individual genes
OR• Can involve changes in piece of
chromosomes
![Page 25: Analyze and evaluate the effects of other evolutionary mechanisms, including genetic drift, gene flow, mutation, and recombination. Unit 11 7F.](https://reader035.fdocuments.net/reader035/viewer/2022062718/56649e865503460f94b89293/html5/thumbnails/25.jpg)
• If the mutation is beneficial to the organism, the mutation will be passed on to offspring • Slowly over time the mutation
will become more common in a population
![Page 26: Analyze and evaluate the effects of other evolutionary mechanisms, including genetic drift, gene flow, mutation, and recombination. Unit 11 7F.](https://reader035.fdocuments.net/reader035/viewer/2022062718/56649e865503460f94b89293/html5/thumbnails/26.jpg)
Recombination
• A source of heritable variation• Occurs for 2 reasons:a. Independent assortmentb. Crossing over
![Page 29: Analyze and evaluate the effects of other evolutionary mechanisms, including genetic drift, gene flow, mutation, and recombination. Unit 11 7F.](https://reader035.fdocuments.net/reader035/viewer/2022062718/56649e865503460f94b89293/html5/thumbnails/29.jpg)
Hardy-Weinberg Principle
• States that allele frequencies in a population will remain constant unless one ore more factors cause those frequencies to change
![Page 30: Analyze and evaluate the effects of other evolutionary mechanisms, including genetic drift, gene flow, mutation, and recombination. Unit 11 7F.](https://reader035.fdocuments.net/reader035/viewer/2022062718/56649e865503460f94b89293/html5/thumbnails/30.jpg)
Hardy-Weinberg Equation
P2 + 2pq + q2 = 1
Homozygous dominant
Homozygous recessive
Heterozygous
p = dominant allele frequency q = recessive allele frequency
![Page 31: Analyze and evaluate the effects of other evolutionary mechanisms, including genetic drift, gene flow, mutation, and recombination. Unit 11 7F.](https://reader035.fdocuments.net/reader035/viewer/2022062718/56649e865503460f94b89293/html5/thumbnails/31.jpg)
Genetic Equilibrium
• The situation in which allele frequencies remain constant (don’t change)• If frequencies don’t change, the
population doesn't evolve
![Page 32: Analyze and evaluate the effects of other evolutionary mechanisms, including genetic drift, gene flow, mutation, and recombination. Unit 11 7F.](https://reader035.fdocuments.net/reader035/viewer/2022062718/56649e865503460f94b89293/html5/thumbnails/32.jpg)
Conditions required to maintain genetic equilibrium:
1. Random mating2. Population must be large3. No immigration or emigration4. No mutations5. No natural selection