Priorities in the Application of Genetic Principles to the Human Condition: A Dissident View

PRIORITIES IN THE APPLICATION OF GENETIC PRINCIPLES TO THE HUMAN CONDITION: A DISSIDENT VIEW JAMES V. NEEL* The human condition in the year 1991, viewed broadly, is a cause of deep concern to many scientists, including this one. There are many, many facets to the complicated problems humankind faces. Because I am a geneticist, I will here concentrate on genetic issues. I do not mean to imply these are necessarily the most important ones that the future holds, but simply that these are what I am best qualified to discuss. As one especially interested in the genetic problems of populations (rather than of individuals), my orientation is toward the dynamics of the gene pool, how it got to be what it is, what the future holds for it, how to protect it. The human gene pool is simply the collective genetic material of our species. Much of my time in the past 20-30 years has been devoted to studies of some of the remaining relatively unacculturated human tribal populations residing in the rain forests of South America, especially the Xavante and the Yanomama, and to the genetic effects of the atomic bombs in Hiroshima and Nagasaki. In what follows, I shall make frequent references to the resulting experiences, which have heavily shaped my thinking. The Human Condition Since the advent of civilization, but increasingly in recent years, Homo sapiens, step by step, has been abandoning the population structure that was central to our amazing evolution. At the same time, in our explosive numerical growth and accompanying exploitive environmental policies, This address was presented as the Second George and Marie Andros Lecture of the University of Chicago, Pritzer School of Medicine, March 7, 1991. *Department of Human Genetics, University of Michigan Medical School, Ann Arbor, Michigan 48109-0618.© 1991 by The University of Chicago. All rights reserved. 0031-5982/92/3501-0764$01.00 Perspectives inBiology and Medicine, 35, 1 ¦ Autumn 1991 49 humankind imperils the prospects for a comfortable existence for the species even at its present numbers. The only real asset of the human species is its gene pool in all its glorious and poorly understood diversity. In this presentation, I first try to assess the current threats to the integrity of that gene pool and its optimal phenotypic expressions, then address the role of the geneticist in meeting these threats. The problems humankind faces are both short and long range. We consider the short range first, then move on to the long range. "Short range" to the population geneticist implies the next two or three generations—not the 2—6year cycle of the politician. SHORT-RANGE ISSUES: BURGEONING POPULATIONS AND RAPIDLY SHRINKING RESOURCES Within my lifetime, which now encompasses three generations, the world's population has gone from some 1.8 to 5.3 billion persons. In one more generation, by the year 2020, if birth and death rates follow the "middle" projection, it should reach approximately 8.0 billion. Somewhere along the way from a tribal, Yanomama-type existence to modern civilization, we have lost the commitment to restraints on population growth exhibited by most "primitive" populations [I]. At the same time, the developments of the past several centuries with respect to sanitation, vaccination, and antibiotics have removed many of the checks on population growth formerly imposed by disease. Whereas much has been made in Western Culture of the motivation (justification) provided by the passage in Genesis that gives man dominion over the Earth and enjoins him to be fruitful and multiply, Muslims, Buddhists, and Confucians have been equally fruitful where the opportunity arose. In synchrony with the growth of population, there has been an accelerating depletion of the nonrenewable (and renewable) resource base on which this growth has been dependent, well documented during the past decade (summaries in [2—7]). The resulting impoverishment of the environment can be expressed in many ways. Let us first consider the current rate of loss in the agricultural base to feed this expanding population. All figures are somewhat approximate and carry a large error, but the trend is clear. Thus, it has been estimated that global soil losses each year are 24 to 26 billion tons in excess of...