Scientists had long investigated the mechanics and statistical probabilities of simple heredity (see Gregor Mendel's copious documentation on the basic traits handed down through generations of peas). Farmers had long practiced artificial selection for the improvement of agriculture. Botanists, physicians, and biologists had worked to eliminate diseases and disorders through the discovery of therapeutic compounds. The merging of these three domains created the terrifying field of eugenics: the science of improving humanity through sterilization and euthanasia.Were it not for the discrediting of the field by outspoken scientists, we might still be living in the dystopia shown in this documentary. Even former eugenicists had to eat crow to crack the foundations of this insidious programme. A few outrageous legal cases brought to light the shameful practice of sterilization. And finally the horrors of the Holocaust followed eugenics to its logical conclusion: large scale euthanasia and genocide.It's is a cautionary tale. We have no guarantee that today's promise of genetic engineering will not produce an equally disastrous outcome again.