Which method do scientists use to track evolutionary changes over time

      Scientists use phylogenic comparative methods to track evolutionary changes over time.      

Nazi Germany was under dictatorship with a leader who was insane. the effects of the Holocaust left millions of people homeless and billions of dollars to rebuild all of Europe. If Hitler would of actually did what his dream was every race beside whites would be dead. That would of also lead into the whole world become Nazi German so every country would be under dictatorship.