Click the Calculate button.
Put the fitness of the genotypes (relative or numbers) and
you can run one generation at the time by pressing the button +1 generation!,
or you can get a graph over gene frequency changes over 60 generations by pressing
the Run button. The corresponding data you can extract over the clip board in the
lower left window.
You can also start the process by putting your gene frequencies and
there after take some selections rounds.
For practical reasons delta q is put to 0 for values less than .000001.
Sometimes when delta q is less than .0001 there are problems with rounding
and some browsers can not see the results proper.
If you have a genetic system for instance yellow coat colour in the Labrador Retriever, where the recessive (yellow) have the fitness 1-s by selection you get:
Genotype EE Ee ee Total ---------------------------------------------------------------- Observed number 141 80 11 = 232 Frequency p2 2pq q2 = 1.00 Fitness 1 1 1-s Proportion p2 2pq q2(1-s) = 1-sq2 after selection ---------After selection the gene frequency q' can be calculated by the gene counting method, q' is the gene frequency in the next generation, is calculated as half of the heteroygotes plus the surviving recessive relative to half of the proportion of all surviving genes, that is equal 1-sq2.
q' = (2pq/2 + q2(1-s))/(1-sq2)To test the applet put the observed number and press the Calculate button. You then get q=0.2198, if you have s(aa)=0 and press the +1 generation button you get q'=0.1802.
Genotype AA Aa aa Total Observed numbers 225 157 43 Frequency p2 2pq q2 = 1,00 Fitness 1-s1 1 1-s2 Proportion p2(1-s1) 2pq q2(1-s2) = 1-p2s1 - q2s2 after selection
How many generations will it take to reach equilibrium within 0.02 units ?
What would happen after 5 generations selection if s1 = -0.3 and s2 = -0.5
Would there be any equilibrium ?