Please think for a moment about your mother, and imagine she is standing two steps away from you at this very moment.
Now think of your grandmother standing another two steps away, just next to your mother. There are three of you now. Then add her mother – your great grandmother – two further steps away.
Including yourself, that’s four people standing in a row and, as the average generation in human evolution has been approximately 25 years, you and these three women would, statistically, represent 100 years of evolution.
Go on, imagine the next four mothers – we are now approximately 200 years back in time. And then imagine ...