Some possible bearings of genetics on pathology

In this classic lecture, a leading geneticist turns a skeptical eye toward the claim that modern genetics is merely a catalog of oddities—albinos, dwarfs, and other pathological forms. He argues that such a view underestimates the discipline’s broader impact, especially for physicians seeking to understand disease at its most fundamental level. By confronting the old‑fashioned evolutionary perspective, he sets the stage for a thoughtful discussion of how heredity informs pathology.

The speaker explains that every deleterious gene has a normal counterpart, an allelomorph, and that studying one inevitably reveals the behavior of the other. Using the familiar fruit‑fly cross between long‑winged and vestigial‑winged specimens, he illustrates how recessive mutations lie hidden in the germ line, only appearing when paired with a matching partner. This simple experiment demonstrates the power of Mendelian segregation to trace both harmful and benign genetic factors, suggesting that the same principles can illuminate human diseases.