4 Random genetic drift

4.1 Random genetic drift and binomial sampling

4.2 The Wright-Fisher Model of random genetic drift

4.3 The diffusion approximation

4.3.1 An approach looking forward

4.3.2 And approach looking backward

4.3.3 Absorption time and time to fixation

4.4 Rndom drift in a subdivided population

4.5 Effective population size

4.5.1 Fluctuation in population size

4.5.2 Unequal sex ratio, sex chromosomes, organelle genes

4.5.3 Variance in offspring number

4.5.4 Effective size of a subdivided population

4.6 Gene trees and coalescence

4.6.1 Coalescent effective size

4.6.2 Coalescence with population growth

4.6.3 Coalescent models with mutation

4.6.4 Applications of coalescent methods

4.7 Theoretical implications of coalescence

4.7.1 Coalescent models with recombination

4.7.2 Linkage disequilibrium mapping