Five hundred million years ago, our eyeless ancestral creatures suddenly developed eyes, a dramatic leap in evolution. What enabled our ancestors to evolve with eyes has long been a mystery. Now, scientists are close to a solution, using cutting-edge DNA research.

Human mothers raise fetuses inside their wombs and breast feed their babies for a long time after birth. What made humans evolve so that we raise our children so affectionately? Scientists believe that our ancestors experienced unforeseen dramatic changes in DNA under threats of extinction.