The Theory of Population Genetics , 99 



the more genes that are lost or fixed, the fewer heterozygotes there 

 are in the population. The process of reduction of heterozygosity 

 through loss and fixation at various loci is known as the decay of 

 variability. 



Fig. 6.1 I Probability distribution of p in 50 and 5,000 

 offspring from a parental population in whicli the gene 

 frequency was p = .50. For details see text. 



0.300 0.350 0.400 0.450 0.500 0.550 0.600 0.650 0.700 



Gene frequency 



Fig. 6.2 I Model illustrating genetic drift. See text for explanation. 



Gene frequency 



Generations 



