I was going some genealogy research into my massive family tree. We have several lines of our family traced hundreds of years back. I found out that I'm even a direct descendant of someone from the Salem Witch Trials, which is pretty darn cool if you ask me. But I was wondering, how much are we REALLY like our ancestors? My 12th great-grandfather was a pretty important figure for his day. And I take pride in knowing that I'm related to him. Yet, if each time two people come together and reproduce, that essentially cuts the DNA from one line in half each time, correct? So, by my math (dividing by two each time for twelve generations), the DNA I share with my 12th great-grandfather is only about 0.04% of my total. Is this correct?