List, I have found this pattern of haplotype clustering within individuals from Norway, Sweden and Finland on Chr 1 using 38.5k SNP: Unique haplotypes not shared with others - 1 344 (typical between 15 to 50 per individual) Haplotypes shared between 2 ind - 157 Haplotypes shared between 3 ind - 30 Haplotypes shared between 4 ind - 3 Haplotypes shared between 5 ind - 2 Haplotypes shared between 6 ind - 2 As this shows widespread haplotype clusters are much rarer than those shared with only two individuals, but the "unique" haplotype clusters appears to be absolutely highest at the individual level. This raises the questions why its like this. I suspect its the following reasons: 1. The effect of recombination splitting or killing haplotypes. However the maximum haplotype size in clusters is 500kb questions recombination as the effect. 2. The effect of limited population data. Its possible more individuals and populations would reduce the number of unique haplotype clusters. 3. The effect of undetected errors in the genotypes. However no correlation between high unique haplotypes found in individuals and high detected genotype error rate for these. 4. The effect of incorrect phasing as the result of errors in genotype or/and ordinary phasing error as result of the model used. 5. The effect of haplotype or mutation extinction. Recent individual haplotypes or mutations have limited spread generally, while older haplotype clusters or mutations have larger geographic spread. Do anyone else have more suggestions to explain this? Anders