| The Magazine of the CALIFORNIA ACADEMY OF SCIENCES |
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Reviews A Cultural Explosion The Dawn of Human Culture, by Richard Klein and Blake Edgar, John Wiley & Sons, New York, NY, 2002. 288 pp., $27.95 hardcover According to Stanford University archaeologist Richard Klein, a “big bang” in human behavior occurred about 50,000 years ago. That time period, he says, coincides with a worldwide flowering in cave paintings, jewelry, carved egg shells, and improved stone and bone implements. In The Dawn of Human Culture, Klein and science writer Blake Edgar explain how this explosion in art and artifacts came to be. Klein and Edgar begin by tracing the ancestry of Homo sapiens. They describe and evaluate the plethora of human fossils and associated artifacts that have confused the public and students of human evolution alike. They carefully explain the time, place, evidence, and in some instances the controversies surrounding the lineage of hominid species. The genera Australopithecus and Paranthropus, for instance, may include more than seven species, depending on who is counting. Klein sorts out the genus Homo, which began some 2.5 million years ago, and encompasses the extinct habilis, rudolfensis, ergaster, erectus, and heidelbergensis species. The book rightly emphasizes that recent advances in our understanding of human evolution “owe as much to methods of dating as they do to new fossil and archeological discoveries.” The authors’ explanations of dating techniques such as paleomagnetism, potassium/argon ratios, luminescence, and electron spin resonance are lucid and accessible. However, they could have made it more evident that anthropologists rely heavily on genetic data and “molecular clocks” to determine two key events in human evolution. Mitochondrial DNA comparisons indicated that Homo sapiens originated in Africa about 150,000 years ago, and that Neandertals and Homo sapiens are separate species that shared a common ancestor about 600,000 years ago. Klein attributes the leap toward modern cognition to a critical mutation in the human brain that gave us the edge over our sibling species, the Neandertals. They cite the recent discovery of a “language gene,” which is defective in some speech-impaired individuals and families, as an example of a mutation that might have empowered a cultural breakthrough 50,000 years ago. However, his thesis is problematic. Breakthroughs, like births, require a finite gestation time. It’s the equivalent of some future archeologist deducing that an “electronic mutation” in the human brain around 1900 accounts for the sudden emergence of telephones, radio, television, radar, and computers. And since the book went to press, comparisons of this gene in humans and other primates indicate that it arose between 120,000 and 200,000 years ago—about when our species first emerged. Overall, the book provides an excellent, up-to-date presentation of what is known about human fossils and artifacts. But the case that the dawn of human culture came up like thunder 50,000 years ago is, in the words of the Scottish court, “not proven.” Flowers East of the Sierra Wildflowers of the Eastern Sierra and Adjoining Mojave Desert and Great Basin, Laird R. Blackwell, Lone Pine Publishing, Renton, WA, 2002. 255 pp., $16.95 paper In the avalanche of regional wildflower/native plant guides that has descended on a nature-starved public, Blackwell’s guide to wildflowers of the eastern slope of the Sierra Nevada and adjacent desert regions stands out for several reasons. It covers a largely neglected, but botanically exciting, 250-mile-long stretch of east-central California and west-central Nevada. Introductory chapters give informative overviews of the region and suggest good botanizing locales. The guide largely covers herbaceous plants, about 30 shrubs, and a few flowering trees. More than 750 color photographs of habitats, plants, and close-ups of flowers enliven the text, demonstrating the spectacular landscapes of the “dry side” of the Sierra. Among them, however, lies the book’s only detraction: a few of the photos are dark, poorly composed, or not in focus. But overall, the quality and usefulness of the natural light photos are very good. In fact, the renditions of these masterpieces of nature makes me yearn to get out-of-doors and head for the hills and high deserts. The guide provides readers with three ways to identify the 366 species covered. A thumbnail photo of each species, organized by flower color, appears at the beginning. The book is then split into the four distinctive life zones that correlate with elevation: Mojave Desert, Great Basin, conifer forest, and alpine. Each of these chapters contains large format photos of the plants arranged by flower color and petal number. If you know the elevation or the vegetation type you are in, your work is made that much easier. Finally, there are indices to families and genera, scientific names, and common names. The text for each species includes distinguishing plant characteristics, the derivation of the plant’s name, its habitats and distribution, its blooming period, and an accessible locality where (and when) the plant has been seen in flower. This guide offers just about everything you would need to locate, identify, and learn something about the common flowering plants of the region covered. It complements two previous wildflower guides (western slope of the Sierra Nevada/Central Valley and the Tahoe Sierra) by the same author, which are equally well-researched and thoughtfully presented. Recommended Reading from the Editors’ Desks State of the World 2003: A Worldwatch Institute Report on Progress Toward a Sustainable Society, W.W. Norton & Company, Inc., New York, NY, 2003. 241 pp., $16.95 softcover The Importance of Species: Perspectives on Expendability and Triage. Edited by Peter Kareiva and Simon A. Levin. Princeton University Press, Princeton, NJ, 2003. 440 pp., $35 paper, $75 cloth. |