University:
The University Of Western Ontario
Course:
Biology 2290F | Scientific Method in Biology
Academic year:

2022
Views:

499

Pages:

3
Author:

Kyuwon J.

HWE assumption ● Hardy Weinberg Equilibrium ○ No gene flow ■ No emigration or immigration ○ Population size infinite ○ No selection ○ No mutation ○ Random mating ■ No selective mating ● In HWE eq there will be no genetic evolution happening ○ It does not mean evolution is not happening ○ Evolution = change in allele frequency HWE example Using observed number of genomes for calculation of allele frequencies ● 450 CRCR indiv ○ 450 X 2 = 900A1 ● 500 CRCW indiv ○ 500 X 1 = 500A1 ○ 500 X1 = 500 A2 ● 50 CWCW indiv ○ 50 X 2 = 100 Therefore… ● P = (900+500)/2000=0.7 ● q = (900+ 100)/2000 = 0.3 ● p+q=1 ● Use allele frequency for calculation for expected genotypical frequency ○ A1 = p = 0.7 ○ A2 = q= 0.3 ○ p2 + 2pq + q2 = 1 ■ p2 = (0.7)2 = 0.49 CRCR individuals expected ■ q2 = (0.3)2 = 0.09 CWCW individuals expected ■ 2pq = 2(0.7)(0.3) = 0.42 CWRW individuals expected ● Compare obvs and exp gene freq ○ When HE matches all condition of HWE is met = no real evolution is occurring ○ When not HWE the population is evolving ■ Ex ● p2 = (0.7)2 = 0.49 A1A1 individuals expected ● q2 = (0.3)2 = 0.09 A2A2 individuals expected ● 2pq = 2(0.7)(0.3) = 0.42 A1A2 individuals expected The observed value and expected value does not matches therefore there are active evolution going on in this environment