"We are inescapably the result of a long heritage of learning, adaptation, mutation and evolution, the product of a history which predates our birth as a biological species and stretches back over many thousand millennia... Going further back, we share a common ancestry with our fellow primates; and going still further back, we share a common ancestry with all other living creatures and plants down to the simplest microbe. The further back we go, the greater the difference from external appearances and behavior patterns which we observe today."