
Originally Posted by
sparkey
You can only have one path through the tree. Think about it: If your grandfather had one mutation A, and passed it onto your dad and uncle, and then your dad got mutation B and passed it onto you, while your uncle got mutation C, it wouldn't be possible for you to be "a bit of B and a bit of C." You'd just have A and B.
There is one complication: Some SNPs are volatile and can appear in multiple unrelated lineages. However, even when that happens, the two lineages maintain different hierarchical names.