At 3/23/2018 00:28, Carol Anne wrote >Although we get 50% of our DNA from each parent, 25% from each >grandparent is just an AVERAGE. > >One real life example where a grandchild and all 4 grandparents were >tested produced these results. > >Paternal grandfather 27.7% >Paternal grandmother 26.3% >Maternal grandfather 17.7% >Maternal grandmother 32.3% > >This is due to the RANDOMNESS of DNA inheritance. And that randomness >is the reason why, after 4 or 5 generations, you have ancestors from >whom you received no DNA at all. As you go further and further back >you have more and more ancestors from whom you received no DNA at all. Another example is given by Bettinger & Wayne in "Genetic Genealogy in Practice" (p.68) where parent had four children with the following percentages which is a clearer picture of how averages play out: Child P-GF P-GM M-GF M-GM Average April 21.2 28.8 23.4 26.6 25.0 Hiram 20.5 29.5 28.6 21.4 25.0 Corey 30.1 19.9 24.6 25.4 25.0 Samatha 25.5 24.5 18.9 31.1 25.0 Looking at this and considering that we get an average of 12.5% from each great-grandparent, one might conjecture that the small amount that Samantha got from her maternal grandfather _could_ be almost all from just one of her maternal grandfather's parents. Lee