How Similar is Your Y-DNA Haplotype to Your Ancestors?

[esvion]

If I am to understand Y chromosome haplotypes correctly:

Let's say that I am male. I have an X chromosome from my mother and a Y chromosome from my father. Because the Y chromosome is passed directly through my father's paternal line, does that mean I have more in common genetically with my great-great-great-great grandfather on my father's side (in the paternal line) than I do with any great-great-great-great grandfather/grandmother on any other line of my mother's or my father's?non-paternal line? I am assuming that I have 50% of the same DNA as every ancestor in my father's line because we all inherited the same Y-Chromosome since the Y DNA haplotype was created.

Also, my grandfather had his DNA tested recently. Is there any chance that I can have slightly different STR markers that change my Y-DNA haplotype after two generations?

Thanks.

 

[madcat8000]

Actually the only thing you have in common with the men on your fathers side is the Y chromosome. Its tiny in comparison with the other chromosomes and has very little information. All the other chromosomes are recombined (mixed between the mother and father) http://en.wikipedia.org/wiki/Recombination_(biology ) , the only reason the Y chromosome can be traced in such a straight line is because it doesn't have a partner to exchange genes with. The Y chromosome you share from your fathers line would only mean that there is a tiny fraction of 1% more paternal DNA within you.

 

[madcat8000]

And yes it is possible that you might have different markers than your geneitic grand father. However I would bet every single thing on this planet I can lay claim to that you dont.