Go back a few hundred years before modern medicine, life-saving medical procedures, and medical technology. If a person had a genetic anomaly that resulted in a sickness or disease, they would often die. Sad, but this also means that the dangerous genetic anomaly would die with the person, and not get passed on to his or her offspring, assuming the person had died before he or she had a chance to procreate. But thanks to modern medicine, life-saving medical procedures, and medical technology, th. . . See the complete description at http://www.uncomfortable-ideas.com/tools/bg/Bo/ideas