• Share
  • Email
  • Embed
  • Like
  • Save
  • Private Content
Hardy weinberg
 

Hardy weinberg

on

  • 1,921 views

 

Statistics

Views

Total Views
1,921
Views on SlideShare
1,919
Embed Views
2

Actions

Likes
0
Downloads
75
Comments
0

2 Embeds 2

http://onlineacademy.bbsmoodle.com 1
https://smu.blackboard.com 1

Accessibility

Categories

Upload Details

Uploaded via as Microsoft PowerPoint

Usage Rights

© All Rights Reserved

Report content

Flagged as inappropriate Flag as inappropriate
Flag as inappropriate

Select your reason for flagging this presentation as inappropriate.

Cancel
  • Full Name Full Name Comment goes here.
    Are you sure you want to
    Your message goes here
    Processing…
Post Comment
Edit your comment

    Hardy weinberg Hardy weinberg Presentation Transcript

    • Population Genetics
      • The Hardy-Weinberg principle
      • Factors that can change allele frequencies
    • A. The Hardy-Weinberg Principle
      • The frequency of an allele in a population will remain constant over time, provided that the following conditions are met:
        • The population is large and randomly breeding
        • There are no conditions acting on the population to change the allele frequency
    • A. The Hardy-Weinberg Principle
      • Consider a gene that has two alleles, A and a
      • Let p = the frequency of A (in a population) q = the frequency of a
      • The frequency of AA = p 2 The frequency of aa = q 2 The frequency of Aa = 2 pq p 2 + 2 pq + q 2 = 1
    • Hardy-Weinberg Principle
      • Population genetics - study of properties of genes in populations
        • blending inheritance phenotypically intermediate (phenotypic inheritance) was widely accepted
          • new genetic variants would quickly be diluted
    • Hardy-Weinberg Principle
      • Hardy-Weinberg - original proportions of genotypes in a population will remain constant from generation to generation
        • Sexual reproduction (meiosis and fertilization) alone will not change allelic (genotypic) proportions.
    • Hardy-Weinberg Equilibrium Population of cats n=100 16 white and 84 black bb = white B_ = black Can we figure out the allelic frequencies of individuals BB and Bb?
    • Hardy-Weinberg Principle
      • Necessary assumptions
        • Allelic frequencies would remain constant if…
        • population size is very large
        • random mating
        • no mutation
        • no gene input from external sources
        • no selection occurring
    • Hardy-Weinberg Principle
      • Calculate genotype frequencies with a binomial expansion
      • (p+q) 2 = p 2 + 2pq + q 2
      • p2 = individuals homozygous for first allele
      • 2pq = individuals heterozygous for alleles
      • q2 = individuals homozygous for second allele
      • p 2 + 2pq + q 2
      • and
      • p+q = 1 (always two alleles)
      • 16 cats white = 16bb then ( q 2 = 0.16 )
      • This we know we can see and count!!!!!
      • If p + q = 1 then we can calculate p from q 2
      • Q = square root of q 2 = q √.16 q=0.4
      • p + q = 1 then p = .6 (.6 +.4 = 1)
      • P 2 = .36
      • All we need now are those that are heterozygous (2pq) (2 x .6 x .4)= 0.48
      • .36 + .48 + .16
      Hardy-Weinberg Principle
    • Hardy-Weinberg Equilibrium
    • B. Factors That Change Allele Frequencies
      • Mutation
      • Migration
      • Natural selection
      • Random genetic drift