Thomas H. Jukes, Integrative Biology: Berkeley

	1906-1999
	Professor Emeritus

Thomas H. Jukes died November 1, 1999 at age 93, after a long bout with pneumonia. Jukes was accomplished in many fields of biology from biochemistry to nutrition to molecular evolution, and yet it was the grand sweep of the history of life itself that he felt most keenly. He was Professor Emeritus in the Department of Integrative Biology, and during his long career at Berkeley he was a Professor in Residence in the departments of Biophysics & Medical Physics and Nutritional Sciences, as well as a Research Biochemist in the Space Sciences Laboratory. He was a crusader for scientific integrity, and a tireless opponent of what he viewed as scientific quackery and pseudoscience. His research accomplishments graced the prestige of the campus in many ways. He and the late Professor Jack King of UC Santa Barbara almost single-handedly established the empirical basis for the concept of non-Darwinian or neutral evolution, the realization that neutral variants of alleles accumulated in genomes with time. Though these variants may have little or no effect on the phenotype, their relative accumulations can be compared among species to give estimates of relatedness and degree of divergence. This understanding became much of the underpinning for all later studies of molecular evolution (the Cantor-Jukes model was a robust method of calibrating these divergences and differences). Jukes eventually published over 550 scientific papers in several fields of biology and biochemistry.

Tom Jukes was born in Hastings, England on August 25, 1906, and emigrated to Canada in 1924. After receiving a Ph.D. in bio

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chemistry from the University of Toronto in 1933, he moved to California, where he had been drawn by the writings of Mark Twain and Bret Harte. He came west as a postdoctoral fellow, Instructor and Assistant Professor at the University of California--first at Berkeley (1933-34) and then at Davis (1934-42). In this early period he and his colleagues did groundbreaking work on the vitamin B complex, including the isolation of pantothenic acid. At that point he left the University to join Lederle Laboratories. In the 1940s and 1950s, he continued his work in nutrition, chemical research, and the use of chemotherapy in the treatment of cancer. He discovered that feeding small amounts of antibiotics to livestock increases growth--a discovery that revolutionized the meat-producing industry, which now uses far more antibiotics than does medicine.

The emergence of DNA as the central focus of molecular biology changed many careers in the early 1960s, including Jukes.' He returned to Berkeley and harnessed these great molecular discoveries to produce new insights in genetics, nutrition, and evolution. He was one of the founders of the prestigious Journal of Molecular Evolution, and was one of the few scientists in history ever to have a regular column in the journal Nature. He also became involved in controversial issues, such as the fight to ban the use of the pesticide DDT. He argued against the ban because, among other things, DDT had saved so many lives in poor countries as a cheap but effective way to kill malarial mosquitoes, and he saw no strong evidence for its deleterious effects on ecosystems.

His most lasting effects, in addition to these areas, were in the presentation of science to the public. He strongly believed that scientists shared a public trust to educate people about their findings, and to help the public discriminate between valid and invalid claims. He was not interested in diplomacy when scientific principles, practice, or public health was at stake. He carried on a long feud with Stanford Professor Linus Pauling, who Jukes felt irresponsibly extolled untested and unlikely benefits of vitamin C. He was equally impatient with homeopathic medicine, quack cancer remedies such as Laetrile, and panaceic cure-alls. He once applied for and received a membership in the American Association of Nutrition and Dietary Consultants for “Bellman Jukes,”

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his basset hound, and he always treasured a photograph of Bellman with his certificate of membership.

Jukes also served California's public educational system by providing timely and well-considered counsel on scientific content and methodology. In 1972 he protested vigorously when the State Board of Education deliberated requiring “equal time” for creationism, and he eventually served on the committee that drafted the California Science Framework of 1978. Thanks largely to his influence, evolution was restored as an important component in science education in California public schools. Jukes continued through the 1980s and 1990s to expose the scientific fallacies of “scientific creationists” in his columns in Nature and his letters and editorials in other journals.

Tom Jukes was as passionate about the outdoors and sports as he was about science; he seldom, if ever, was half-enthusiastic. He was a veteran climber, a lifelong member of the Sierra Club, and a holder of season tickets to Cal Bear football games for his entire tenure at Berkeley. He also ardently followed the San Francisco 49ers and the Oakland Athletics; few things could give him more pleasure than Dennis Eckersley striking out the other side in the ninth inning. Tom Jukes earned the respect and friendship of a tremendous number of colleagues, administrators, and officials over the years. At holiday times the Jukes house was filled not just with a great contingent of welcoming family members, but by some of the most important people in the University and from all over the world who counted Tom among their most respected friends. He is survived by his wife Marguerite, their daughters Mavis and Caroline and their husbands, his daughter-in-law Sheila, and seven grandchildren. He was one of the giants of 20th-Century biological science.