A Genetic and Cultural Odyssey: The Life and Work of L. Luca Cavalli-Sforza

  • Linda Stone &
  • Paul F Lurquin
Columbia University Press, 2005 248 pp. hardcover, $45 ISBN 0231133960 | ISBN: 0-231-13396-0

For most population geneticists of my generation, The Genetics of Human Populations, by Luca Cavalli-Sforza and Walter Bodmer, was a bible. This classic textbook, along with many ground-breaking research articles by Cavalli-Sforza and his colleagues, inspires us all. Now in his early 80s, Cavalli-Sforza continues to be as productive and inspirational as ever. It is therefore fitting that his life and science (thus far) are chronicled in this new book by Linda Stone, an anthropologist, and Paul Lurquin, a geneticist.

Cavalli-Sforza's career, like those of many eminent scientists, has followed a circuitous path. This makes an interesting story, and the authors, relying on a series of interviews with their subject and his associates, recount it nicely. Cavalli-Sforza trained as a medical doctor in Italy, which may have saved his life because it exempted him from the military draft during World War II. He soon tired of clinical practice and turned his attention to bench science. His early research led to important discoveries about the nature of bacterial conjugation and included a collaboration with Joshua Lederberg. This work attracted the attention of Sir Ronald Fisher, with whom Cavalli-Sforza spent an influential two years in the late 1940s. A photograph of the young Cavalli-Sforza with a stern-looking Fisher is alone almost worth the price of the book.

Cavalli-Sforza's interest shifted gradually to human populations, and in the late 1950s he began the work for which he is now best known. He took advantage of the excellent Italian parish records to study patterns of consanguinity and migration, and he made good use of the available blood group polymorphisms to analyze the phenomenon of genetic drift. He quickly realized that statistical techniques such as principal components analysis and cluster analysis could be used to portray patterns of population relationships. With Anthony Edwards, he pioneered the use of these methods in human population genetics. Appreciating the need for a more complete sampling of human variation, he led numerous blood-collecting expeditions. DNA from many of these samples is still widely used. As new types of polymorphisms became available, Cavalli-Sforza was again in the vanguard. His studies of restriction fragment length polymorphisms, microsatellites and Y-chromosome SNPs helped to set modern standards in population genetics.

A main theme of this biography is the wide range of Cavalli-Sforza's interests. He has worked on topics from the genetics of inherited diseases to the transmission of culture. He is aware that genetic data alone do not provide an adequate portrait of human evolution. Accordingly, he has integrated linguistic, archaeological, historical and genetic data to address fundamental and far-ranging questions. Among these are the origins and diffusion of agriculture (he advocates a model of demic diffusion, in which agriculturalists, not just their technology, spread across the globe) and the origins of modern Homo sapiens (like most geneticists, he supports the African origin hypothesis). Much of this work has been summarized in another monumental tome, The History and Geography of Human Genes (1994). Grand syntheses such as this lead to new insights but also provoke occasional barbs from specialists in other fields.

Cavalli-Sforza's passion for science is another theme of this book. He is accurately described as “glued to his science.” This brings to mind a recent visit to my institution, in which he gave a large public lecture in the morning and a second one in the afternoon, and was still talking excitedly about science (the genetics of Tetrahymena) long after dinner, when colleagues several decades younger had begun to fade.

The final portion of this book is devoted to Cavalli-Sforza's most recent work, which includes his spearheading of the Human Genome Diversity Project. Although the intent of this project was benign, it became one of his most controversial efforts. Some critics perceived the sampling of human variation as a form of 'biocolonialism'. Cavalli-Sforza and other scientists were subjected to a hail of criticism, much of which was inaccurate and unfair. It was claimed, for example, that the real goal of this project was to develop biological agents that could be targeted against specific populations. On the contrary, genetic research has shown that, because humans share so much genetic variation, such a strategy would never (fortunately) be successful. The project was also criticized as potentially supportive of racism. Yet Cavalli-Sforza's research, along with that of many others, helped to prove the biological similarity of all humans and serves, in his words, as “an excellent antidote against bigotry.”

To provide a context for the biographic details, the authors devote considerable effort to describing the science itself. It is here that the book suffers. The explanation of Hardy-Weinberg equilibrium is hopelessly muddled, and there are many factual errors (e.g., restriction enzymes are not used to obtain microsatellite genotypes, and XY females do not lose the SRY gene upon fertilization). Several speculations, such as the hypothesis that dark skin pigmentation reduces the risk of neural tube defects by limiting folate photolysis, are presented as established fact. I would advise the reader to skip quickly through these sections and, for more reliable information, to consult Cavalli-Sforza's own publications.

In spite of its shortcomings in presenting some of the scientific background, this book does an excellent job of portraying Cavalli-Sforza's energy, breadth of interest and enormous contributions to our field. It is an enjoyable excursion through a fascinating career.