Survival of the Fittest: How Life Changes Over Time

Look at your own hands. Now imagine ten people standing next to you. Every person has slightly different finger lengths, skin tone, hand size, and grip strength — even identical twins have tiny differences. Here is a puzzling question: if those differences can be passed on to children, and if some differences help people survive better than others, what do you think would happen to a population over thousands of generations? Hold that thought — this lesson will give you the scientific answer.