Slime: How Algae Created Us, Plague Us, and Just Might Save Us

Kassinger (A Garden of Marvels) looks at the diverse assemblage of organisms that comprise what society collectively refers to as “algae,” which comprises three main groups: cyanobacteria (sometimes called “blue green algae”), microalgae (referred to collectively with cyanobacteria as “phytoplankton”), and macroalgae (the larger seaweeds humans and other animals can see and often consume). Kassinger’s definition is archaic and her groupings artificial; they do not reflect the way scientists think about this assemblage. Yet this does not mean that the work is without merit for lay readers. Kassinger has chosen an ambitious subject to tackle, as many of the organisms thought of as algae are from ancient, diverse, and distantly related lineage. The central part of the book—and where the author seems to be the most comfortable—is about how, why, and where humans consume and use macroalgea, or “seaweed.” Bookending the text are chapters about the roles of cyanobacteria in evolution and that different algae play in the understanding of climate change. Ultimately, Kassinger successfully makes the case for algae’s importance.