There are two types of traits, recessive and dominant. One is more likely to appear in a following generation than the other. Say, one person with black hair is partners to someone with red hair.
Black hair is a more dominant trait than red. Their kids will more likely have black, in following generations though you can still have someone with red hair pop up down the line because the gene is always there and because of its recessive nature it can go generations without coming up again.
I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.