... nneeeeddeedd??Association mapping is done onrandom-mating, and thus much moreheterogeneous, populations, so therewill be more recombinant individuals, and thus fewer individuals are necessary to localize QTLs. ... populations can besomewhat alleviated by starting fromcrosses of four or eight initial parentalstrains. Finally, association mappingrelies on LD between marker alleles and QTL alleles, and any mixing ... classes, and σwis the standarddeviation of the trait within eachmarker genotype class.) In a linkage-mapping study, the different alleles are generally at intermediatefrequency, and in this...