I am looking for more information on what has been suggested as a case of "Genetic Collapse" within my lineage. The Background: 1. Three individuals have been tested (STR @ 111, and SNP) 2. These three individuals have a common ancestor, proven through traditional research) that was married c 1795-1800. 3. Two individuals match of 67/67 and 111/111. The third has a 66/67 and 110/111. 4. The difference comes from DYS576 where the allele counts for the first two is 16 and the third is 19. 5. The mutation rate for DYS576 is 0.01109, or approximately 11 mutations every 1000 generations. 6. All SNPs are consistent. The questions are: What is a "Genetic Collapse"? I can only find proof, or indication, of a "Pedigree Collapse". Can this really be classified as a "Genetic Collapse", or is it simply a matter of a three step mutation and is really a simple case of probability? The DYS576 allele counts might suggest that the 16 value, when compared with the modal value of 19, is ancestral. Comments? Pete