GENE20001 Lecture Notes - Lecture 28: Effective Population Size, Genetic Drift, In Buri District
Document Summary
As we increase sample size we reduce the variance. Magnitude of sampling variation (error) is inversely proportional to the size of the population. Random genetic drift is weakest in large populations. In the top and bottom graph the alleles are fixing. Effective population size ne= number of reproductive individuals. Must take into account no. s of males and females. If nf=nm then ne=nf + nm e. g. 1 bull, 100 cows, n is around about 4. it is so small because there is one male individual. Genetics page 1 e. g. 1 bull, 100 cows, ne is around about 4. it is so small because there is one male individual that contributes to every female individual, shrinking the effective diversity e. g. nf=30. If you just use the formula that isn"t correct. Since the population we"re dealing with is cattle one male can only mate with one female. Genetic drift is not a force it does not determine allele frequencies.
