On the Protective Function of Y-SNPS/Y-STRS, and some Ancient Male Lineages

It is generally taken for granted that we inherit about half of our genes from each parent and so that, roughly speaking, a person's similarity to previous generations drops of at the rate 1/2 ^ g, where g is the number of generations separating that person from their ancestors. On this view it doesn't take many generations before the number of unique similarities between someone and their ancestors begins to dwindle to 0. Here this idea is disputed on the basis that non-recombined, rather than recombined DNA, determines identity, and the rate of decay of non-recombined DNA is very slow. It particular, it is suggested that the function of Y-SNPS/Y-STRS is the regulative function of protecting identity over a large number of regenerations.