If I follow the logic that I have 2 parents , 4 grandparents , 8 great grandparents etc. and a generation equals 25 years ; then after 37 generations , or 925 years ago , I should have a family tree with over 130 billion people , more than all the humans that have ever lived . How is this possible ?
Does grandchildren/grandparents relationship exist in any other living beings than humans ?