Population size and unique recombinations in the UTHSC ARI lines. Fraction of unique recombinations as a function of number of strains wassampled in the set of UTHSC-derived strains. We derived each data point in this highly conservative estimate by randomly sampling the indicated number of strains from the UTHSC-derived strain set, using 100 samples per data point. Up to one directional transition from B6 to DBA and the reverse was scored for each marker interval and the total was divided by the number of intervals with more than 0 recombinations. Heterozygous regions were handled as described for Fig. 2. Fraction of unique recombinations depends on a number of variables including AIL population size, so other crosses may differ.