Acquiring Genomes


January 01, 2003

Teaser: By Lynn Margulis, Hardcover: 256 pages; Dimensions (in inches): 0.91 x 9.46 x 6.36; illustrations: 23 b/w, Publisher: Basic Books; ISBN: 0465043917; 1st edition (June 18, 2002), List Price: $28.00

Current evolutionary theory has it that Darwin's descent with modification (a.k.a. evolution) is the result of natural selection working on random mutations within the genome. The trouble with this scenario, as Margulis and Sagan point out in Acquiring Genomes, is that it is well known the vast majority of these mutations are deleterious-even if an organism with them survives it is less, not more, fit for the environment.

Twenty-five years ago, Margulis suggested that what is perhaps the biggest evolutionary jump of all time-the emergence of the complex cell 2.5 billion years ago-was the result not of genetic mutation but of the symbiotic merger of simple-celled organisms, a theory that is today generally accepted within the scientific community. Margulis and Sagan have now extended this scenario and claim that all important evolutionary change, most particularly the evolution of new species, is the result of symbiotic relationships between disparate organisms. Symbiotic joinings that at first are casual on occasion become permanent, and eventually lead to the exchange of genetic material. According to the authors, it is the exchange of this genetic material, either one-way or two-ways, that is the source of evolutionary innovation.

They complain that the literature supporting this theory has been ignored by the scientific establishment. It is true, for instance, that none of the popular or scholarly writings of Margulis and/or Sagan are cited in the extensive biography in Stephen Jay Gould's monumental The Structure of Evolutionary Theory, or the concept of symbiosis referenced in its equally extensive index. Unfortunately this legitimate complaint gets shaded into a conspiracy theory, which results in moments of distracting hyperbole. Even more unfortunate is the book's poor editing, in detail-repetitions that accumulatively are annoying-and in concept-the lack of a clear narrative arch.

Despite these flaws, the book is an absolute must read for anyone interested in the future of not just evolutionary biology, or even biology as a whole, but the entire life sciences-the future of everything from anthropology to zoology. Also highly recommended are other books that are the result of the productive creative symbiosis between Margulis and Sagan, including What Is Life? (University of California Press); Microcosmos (University of California Press); The Origins of Sex (University of Yale Press) and What Is Sex? (Simon and Schuster); and for those with a background in microbiology Margulis' (solo) groundbreaking Symbiosis in Cell Evolution (W.H. Freeman).


Peter Nevraumont


