Dark Life: Martian Nanobacteria, Rock-Eating Cave Bugs, and Other Extreme Organisms of Inner Earth and Outer Space

The dark life of the title is made up of the masses of bacteria that live deep within the bowels of earth. Taylor (Cave Passages), a veteran caver and professor of communication and theater arts at Henderson State University in Arkansas, explains that these tiny organisms are so abundant that collectively they are thought to weigh more than all the aboveground biomass. Species as yet undiscovered by scientists are thought to abound and to be likely to shed insight into the origin of life. While of interest, none of this is particularly controversial. What is hotly debated is the size of the smallest of these life forms. Taylor argues in favor of the existence of nanobacteria, life so small that many scientists refuse to believe they are possible, contending instead that the patterns observed are due to chemical rather than biological processes. The debate is crucial because the fossils attributed to a rock from Mars are of this sort--if nanobacteria don't exist, traces of life have not been found on the red planet. Mixing science and adventure writing, Taylor describes fact-finding and collecting expeditions into uncharted caves. While he does a commendable job of vivifying the beauty of these strange environments and the passions of the scientists who study them, he is much less evenhanded when discussing the scientific controversy swirling around the nanobacteria themselves. Agent, Esther Newberg. (Apr.)