1 / 8

The Hardy-Weinberg Principle

The Hardy-Weinberg Principle. By: Alex, Jared, Merrick and Larisa. What Is It?. A principle that states in populations in which ONLY RANDOM CHANCE is at work, allele frequencies will remain constant generation to generation. The Hardy-Weinberg Equilibrium. 1pp:2pq:1qq

maia
Download Presentation

The Hardy-Weinberg Principle

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. The Hardy-Weinberg Principle By: Alex, Jared, Merrick and Larisa

  2. What Is It? A principle that states in populations in which ONLY RANDOM CHANCE is at work, allele frequencies will remain constant generation to generation

  3. The Hardy-Weinberg Equilibrium 1pp:2pq:1qq This is the EXPECTED GENOTYPIC RATIO

  4. Example- Blue Eyes & Brown Eyes Say eye colour is inherited by dominance. B is the dominant allele for brown eyes and b is the recessive allele for blue eyes • “p” is the frequency of the B allele • “q” is the frequency of the b allele • So, • The genotype BB = pp • The genotype bb = qq • The genotype Bb = pq According to the Hardy-Weinberg principle, the expected allele frequencies of this population should be 1pp: 2pq : 1qqgeneration after generation For this example, this can also be written as 1BB: 2Bb: 1bb

  5. So According To The Hardy-Weinberg Principle: • The genotypic ratio of this population should remain 1BB:2Bb:1bb generation after generation • But why isn’t this the case in nature?

  6. BECAUSE Any factor that causes allele frequencies to change leads to evolutionary change, and the Hardy-Weinberg principle does not apply

  7. Therefore, It Only Applies If: • Mutation is not occurring • Natural selection is not occurring • The population is large (a smaller population increases chance of genetic drift) • All members of the population breed • All mating is totally random • Everyone produces the same number of offspring • There is no migration in or out of the population

  8. Question Time 

More Related