Q1: Imagine “Johnny Timetravel”-- a handsome charmer a quarter of a century in years on earth-- were to head back to when his grandmother was a young, fertile lass of 22. She’s a comely young woman with swivel-y child-birthing hips and ample bosom. Johnny falls madly in love with Grandma and Grandma falls madly in love with Johnny. If Johnny were to perform sexual intercourse on his grandmother shoot a sperm square into her ripe ovum, would their genetic material be considered “too closely matched” to produce offspring devoid of the usual incestuous problems?
How about if Johnny were to head back another 25 years into the past and perform the same sexual hibbidy-dibbidy on his great-grandmother? Would their spawn be healthy and vibrant and able to live a fine, upstanding life without genetic malfunctions?
How about if Johnny were to head back yet another 25 years and do the “it” with his great-great grandmother? How close are they genetically at four generations back?
In short how far back in time would Johnny have to go to impregnate an ancestor safely and soundly without risk of damaging the Timetravel gene pool?
Q2: If you were to look at the genetic material of all 32 of your great-great-great grandparents, would you have equal amounts from each of them, or will some of their genes get pushed out of the way along the way? Is it possible that my great-great-great grandson/daughter will have none of “me” in them anymore?