10/14 Daily Catalyst Pg. 33 Variation 1. If 1/350 people have blue eyes, what frequency of the population is hybrid for brown eyes? Homozygous for brown eyes? 2. How does sexual reproduction produce variation? 3. Why are point/substitution mutations also known as silent mutations?

10/14 Daily Catalyst Pg. 33 Variation 1. If 1/350 people have blue eyes, what frequency of the population is hybrid for brown eyes? Homozygous for brown eyes? 2. How does sexual reproduction produce variation? A population contains a vast number of gene combinations. Sexual reproduction reshuffles alleles into fresh combinations. 3. Why are point/substitution mutations also known as silent mutations? These mutations may not change the amino acid and the protein so the mutation have not effect!

10/14 Class Business Pg. 33 Variation John Ehret Patriots Bring the `Pain Spirit Day Extra Credit Quiz #7: Average: 1.72 Top Score: Travia, 3.7

10/14 Agenda Pg. 33 Variation Daily Catalyst Class Business Hardy-Weinberg problem Variation notes Debate Prep Homework: 137-142

Hardy Weinberg Equilibrium There are 100 students in a class. Ninety-six did well in the course whereas four blew it totally and received a grade of F. Sorry. In the highly unlikely event that these traits are genetic rather than environmental, if these traits involve dominant and recessive alleles, and if the four (4%) represent the frequency of the homozygous recessive condition, please calculate the following: A. The frequency of the recessive allele. B. The frequency of the dominant allele. C. The frequency of heterozygous individuals.

Essay Prompt Of all the mutations that occur, why do only a small fraction become widespread in a gene pool? Most mutations occur in somatic cells that do not produce gametes and are lost when the organisms die. Of the mutations that occur in the gametes, most do not have an effect on phenotypes and natural selection will not act on it. If you do have a harmful mutation, most will not survive to reproduce.

Causes of Evolution 1. Mutations 2. Sexual Recombination 3. Genetic Drift 4. Genetic Flow 5. Natural Selection

Genetic Drift: Unpredictable changes in allele frequencies from one generations because of a populations finite size Reduces genetic variation

Bottleneck Drift A reduction of a population, typically after a disturbance, such that the survivors no longer represent the original population Example?

Founder Effect A small isolated group that may establish a new population. Represent a distinct gene pool from the parent gene pool Example?? (page 462)

Gene Flow: Genetic additions and/or subtractions from a population resulting from the movement of individuals. How has this been important to humans?

Genetic Variation Key Point #1: Natural Selection accumulates and maintains favorable genotypes in a population. WE NEED GENETIC VARIATION!

Variation in Variation (get it??)

Examples of variation Key Point #2: Polymorphism: Two or more distinct morphs represented in high amounts Morphs: different forms of a characteristic

Examples of Variation Kordell mentioned yesterday, that he has noticed that in different geographical locations, he has seen traits that are more common in areas and not as common in other.

Examples of Variation Key Point #3: Geographic variation: Differences between gene pools of separate populations

Cline: page 464

Natural Selection Directional (pg. 465) Stabilizing (pg. 466) Disruptive (pg. 466)

Directional Selection

Stabilizing Selection

Disruptive Selection

Heterozygote Advantage: Pg. 466