For four billion years, life on earth was shaped solely by natural selection and random mutation.
Then, a few thousand years ago, people began hybridizing plants, breeding animals, and altering the environment.
Today, our dogs are not a natural product, and neither is cotton, cauliflower, or corn.
Birth control and vaccines, heart surgeries and insulin, antibiotics and aspirin keep us removed from the vagaries and perils of the natural world.
Today we stand on the edge of being able to edit genes quickly, cheaply, and with great accuracy thanks to CRISPR technology.
Will we make our children taller? Will we wipe out defective recessive genes that lurk unseen in our own lineage? Will we decide the gender of our children and the color of their hair and the number of fingers they have on each hand?
Will we eliminate cancer in dogs, and engineer faster running dogs or stronger pulling dogs?
As both Voltaire and Spiderman have noted, with great power comes great responsibility.