1 / 11

Hardy-Weinberg Equillibrium

Hardy-Weinberg Equillibrium. Do Now: Consider the following gene pool: P = .50, Q=.50 What are f(AA), f( Aa ), and f( aa ) as predicted by the Hardy-Weinberg equilibrium?. Hardy-Weinberg: The assumptions.

kirby
Download Presentation

Hardy-Weinberg Equillibrium

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Hardy-Weinberg Equillibrium Do Now: Consider the following gene pool: P = .50, Q=.50 What are f(AA), f(Aa), and f(aa) as predicted by the Hardy-Weinberg equilibrium?

  2. Hardy-Weinberg: The assumptions • For the Hardy-Weinberg equation to represent a population perfectly, some very unlikely (or impossible) things would have to be true: • No mutation (DNA changes) • No natural selection • No migration into or out of the population • All members of the population breed randomly, and produce the same number of offspring. • The population is infinitely large

  3. HW = no evolution The HW equilibrium represents a theoretical state where evolution is not occurring. That’s why allele and phenotype frequencies of a population in HW equilibrium remain constant over time In nature however, all populations evolve. Populations of organisms can never actually be in Hardy-Weinberg equilibrium.

  4. Populations Evolve Populations of organisms change over time. The rate of evolution is measured by the change in allele frequencies in a gene pool over time.

  5. So Why Use HW? By comparing the genotype frequencies a real-world population to the expected HW equilibrium population, we can determine what type of evolution is happening!

  6. P = 0.50, Q = 0.50 What genotype is being selected for in the environment?

  7. Modes of Selection

  8. Mode 1: Stabilizing Selection The moderate phenotype is selected for. P and Q become more equal over time, since heterozygotes (2pq) are becoming more common

  9. Mode 2: Disruptive Selection The moderate phenotype is selected AGAINST. f(Aa) will be less than predicted by the HW equation.

  10. Mode 3: Directional Selection One homozygous genotype or the other is selected for. f(AA) or f(aa) become greater over time.

  11. The Quiz The quiz is open note. It only includes problem solving with the H-W equation. You have the remainder of the period.

More Related