We are all related

If you try and draw a complete family tree backwards (from you to your parents to your grand parents etc) it grows exponentially. Eventually the number of people in your tree would have to exceed the population of the planet at that time. This means everyone alive today has at least one person in history we are all some how related to. It seems so counter-intuitive but there you have it as was recently shown in a Nature article (see This for summary). Now this is far from the proverbial Adam or Eve, but as the article mentions, pure religions or races are therefore impossible. So next time you feel ashamed of your family/relatives remember everyone is your relative!