The arrogance of teratology: A brief chronology of attitudes throughout history.

While the discipline of Teratology has existed for about 60 years, there has been a deep interest in the causes of human malformations for millennia. Absent the scientific method and acting on fervent beliefs that made sense to ancient/medieval populations, "mechanisms" were described and prognostications of future events were assigned to terata resulting in tragic (and unwarranted) sequelae. This article examines the collective beliefs and thinking within various eras in the hope of providing lessons to inform future behavior. The eugenics movement is an informative, recent example. Science of the 19th century had unraveled some of the mysteries of development and the role of genetics in determining birth outcomes. There was, however, a deep misunderstanding about the enormous amount of information that had yet to be uncovered. Based on immature science and faulty assumptions, it was suggested that "unfit" individuals be euthanized and their parents sterilized. Such "solutions" would be considered deplorable today. Surprisingly, such a reprehensible program was supported (at least in part) by many intelligent and highly regarded individuals. Today, it is imperative that we enter into the era of molecular biology and gene editing cautiously and perspicaciously. The history of teratology has elucidated our inability to understand where our new technologies and actions might take us and how unintended consequences could disrupt even our most carefully thought-out plans.