Perspectives in Biology and Medicine

DEGENERATE HEREDITY: THE HISTORY OF A DOCTRINE IN MEDICINE AND BIOLOGY MARK S. LUBINSKY* Introduction Although no longer in use, degenerate heredity was a well accepted and scientifically influential doctrine from the end of the eighteenth century well into our own. It centered on weakness of the hereditary force that kept form and function constant from generation to generation . This weakness could increase with time, or over generations, and could cause a wide range of structural, physiological, and mental abnormalities in offspring. Interestingly, standard genetic histories fail to even mention this once popular concept [1, 2], probably for several reasons. Certainly preemption by eugenic charlatanry makes it easy to discount. McKim wrote of "abundant and incontrovertible . . . evidence for the hereditary transmission of the taints of degeneracy" [3, p. 85] and later concluded that "the surest, the simplest, the kindest, and most humane means for preventing reproduction among those whom we deem unworthy of this high privilege is a gentle, painless, death" [p. 188]. This statement hardly suggests an objective scientific analysis. Technical issues and reasonable social concerns were the most important influences on the theory of degenerate heredity, but they are difficult to ferret out. The concept was poorly covered in the biological literature since its uses were mostly medical, and even there concentrated in a few specialties. And, although concerned with inheritance, it had little to do with issues connected with modern genetics. Ultimately rejected, and without any scientific successor, it was an intellectual deadend that led away from current ideas. The author gratefully acknowledges support from the 1989 Osier fellowship at the Osier Library, McGiIl University, Montreal. *Medical Genetics Center, Medical College of Wisconsin, Children's Hospital of Wisconsin , P.O. Box 1997, MS# 716, Milwaukee, Wisconsin 53201.© 1993 by The University of Chicago. All rights reserved. 0031-5982/93-3701-0842101.00 74 Mark S. Lubinsky ¦ Degenerate Heredity Here, the doctrine is traced from its eighteenth century origins to its death in the twentieth. This was a time of social, medical, and scientific ferment, and the theory was influenced by Romanticism, Darwinism, the end of Vitalism, and the birth of modern genetics, as well as by other movements. The evolution of the concept offers important insights into early ideas about heredity and is a fascinating story well worth examining for its own sake. Eighteenth Century Origins Concerns over degeneration and heredity go back to ancient Greece [4, p. 293] but were traditionally more folklore than science. A formal theory first arose in response to eighteenth century problems with changing concepts of species. Before, species had been fairly nonspecific ; hybrids between groups, including men and animals, were widely accepted [5], as were transformations of types. However, after the Reformation , religious concerns began to emphasize a created system that was by definition perfect, with limited room for variety. Species increasingly became distinct natural units and, more importantly for our discussion , constant. Linnaeus's taxonomy of 1735 and after stressed this new definition of species as "real" entities with a biological foundation, rather than just convenient categories [6, pp. 254—259]. Variation became a major issue as religiously supported beliefs in fixity had to be reconciled with observed differences within species. The same theological focus made the biblical fall from Eden a powerful example of how created attributes could be lost. Certainly routine experience showed that if God's work could not be bettered, it could still be damaged, and congenital anomalies were often dramatic evidences of failures of natural design. Such changes were viewed not as true differences in the species plan, but instead as truncated versions. In this context degeneration was linked to inheritance in the work of Buffon, the famed French naturalist who Darwin [7, p. xvi] felt was the first to scientifically deal with the problem of change. His thoughts varied over time and were inconsistent , but his basic ideas are well presented in the essay "De la Degeneration des Animaux" [8, v. 14], from 1763. Here, Buffon suggested that created forms could be subject to degenerations —losses or distortions of traits caused by mutilations or by habits . "Dogs who, for a few generations, have had their ears and tail cut, transmit these defects, in a...