Cradle of Life: The Discovery of the Earth's Earliest Fossils

Until the mid-1950s, biologists, geologists and paleontologists seeking early life's traces had to make do with fossils from the Phanerozoic periods, which represent only 15% of the time that life has existed on Earth. The first 85%--the Precambrian Era--remained obscure. But since the discovery of ""microfossils"" in Canada's Gunflint rocks, ""Precambrian studies have boomed"": these fossil microbes constitute our direct evidence about primordial life. Schopf, a professor at UCLA's Institute of Geophysics, adopts an unusually informal first-person style for this rangy exploration of how Precambrian fossils came to light and what they've taught us. The author covers the history of evolutionary thought and the exploits of field paleontologists, as well as the trajectory of his own career. The casual prose brings both rewards and perils. Most readers will want to know, for example, that in 1924 Aleksandr Oparin explained how simple molecules with carbon, hydrogen, oxygen and nitrogen might have ""given rise to the first cells."" Few, however, will care that Schopf once lunched with Oparin (""It was thrilling!"") or that a limestone slab Schopf found in China ""is now embedded in the entry way at our home."" What reader needs to be told that, ""in science, technical terms are simply shorthand notations for ideas""? Subtract the self-referential elements and Schopf's book is a very clear introduction to the first living things. Final chapters tie these early organisms to the photosynthetic cyanobacteria on today's earth, digress into the history of paleontological frauds and explain what Schopf thinks is right and wrong in NASA's search for fossilized life on Mars. 80 b&w illustrations. (May)