So figuring out who's mother and who's daughter is as easy as labelling their genomes a,b and c,d and noticing which of them has the property that, eg, ccccccccccccc is the same as aaaabbbaabbbb.
Neat! (And not even all that subtle; if I'd thought a bit harder about what I supposedly learned in high school, I could've figured it out.) This fact about the asymmetry of the parent-child relationship suggests a more general question: How much can you deduce about the precise way in which two blood-relatives are related simply from looking at their genes? This can be a real-world issue ("And is it your sworn testimony before this court, as an expert in the field of genetics, that this man cannot possibly be the nephew of Howard Hughes?"), but I could imagine it also giving rise to some mathematically amusing albeit unrealistic puzzles ("Assume an infinite genome..."). Michael? Jim