Index of Association
This statistical test attempts to measure the extent of linkage equilibrium within a population by quantifying the amount of recombination among a set of sequences and detecting association between alleles at different loci (Maynard-Smith et al., 1993). The Index of Association (IA) is calculated as follows:
IA =VO/VE -1
if V0 is the observed variance of K and VE is the expected variance of K, where K is the number of loci at which two individuals differ. If there is linkage equilibrium because of frequent recombination events, the expected value of IA is zero. Clonal populations are identified by an IA value that differs significantly from zero.
This analysis requires only the allelic profiles. Again, individual isolates may be selected or deselected from inclusion using the 'Isolate Selection' dialog reachable from the 'Options' menu. To run the analysis, click 'Analysis ... Tests for Recombination ... Index of Association'. Again, individual isolates may be selected or deselected from inclusion using the 'Isolate Selection' dialog reachable from the 'Options' menu.