The Network of Life: A New View of Evolution

“The current, conventional narrative for evolution... is outdated,” according to this eye-opening analysis. Mindell (The Evolving World), a researcher at UC Berkeley’s Museum of Vertebrate Zoology, contrasts “vertical evolution,” or the traditional Darwinian account in which species differentiate and branch off from each other, with “horizontal evolution,” which emphasizes how species sometimes “coevolve” in tandem with other organisms, transfer genes through means other than reproduction, or merge by producing distinct hybrids. Highlighting surprising examples of each, Mindell explains that certain kinds of bacteria can affect the DNA of their hosts and notes that some insects and slime molds “have picked up bacterial genes allowing them to synthesize vitamins and sequester iron.” Species mergers have played a pivotal role in evolution, Mindell contends, describing how the joining of two kinds of bacteria 1.8 billion years ago gave rise to mitochondria, whose ability to metabolize oxygen enabled the emergence of all animals, plants, and fungi. Mindell argues that these findings raise questions about where one organism ends and another begins, discussing how humans rely on microbes in the gut that “produce vital nutrients, regulate the immune system,” and perform other essential tasks. The heady ideas will change how readers understand some of biology’s most fundamental concepts. This mesmerizes. (June)