In the Natural History’s February 2009 article titled “Could an Ant Colony Read this Book,” ecologist Robert Dunn tracks the long-term collaborative efforts of Edward O. Wilson and Bert Holldobler, leading up to their new book: The Superorganism. In their new book,  Hölldobler and Wilson

. . .  have breathed new life into a notion that intrigued scientists before World War I: that a colony of social insects is analogous to an individual. The concept of the superorganism—which compares a colony’s members to a body’s cells and sometimes its nest to the body’s skeleton—fell out of favor as research increasingly focused on the genes of individuals. Hölldobler and Wilson, building on new insights into the evolution and workings of insect societies, seek to bring it back. To them, “superorganism” is more than a metaphor; it is a unit in the hierarchy of biological organization, falling somewhere between an ecosystem and an individual. And, they argue, it is the most useful level of biological organization at which to examine how pieces are assembled to make a whole—be it an association of bacteria, a single creature, or a whole society—as well as to understand what holds all organisms together, even when the pieces struggle toward independent goals.

According to Dunn (and Wilson and Holldobler), ants and other highly social creatures (such as termites, and honeybees) offer a rare opportunity to study the process by which individuals meld into an unified organism.   Other examples include the early symbiosis of mitochondria with an early form of bacteria, plant cells (“which arose when a eukaryotic cell . . incorporated a photosynthetic bacterium”) and multicellular creatures in general (e.g., human beings). In each of these examples, individuals gave up reproduction “either partially or completely, to work for their overbearing mother.”

Wilson and Holldobler point to group selection (and individual selection) as a key component of the evolution of highly social species.   “In group-selection models, evolution favors the groups whose member cooperate more effectively, regardless of whether such cooperation helps a given individual (or that individual’s kin) reproduce.”  The key to allowing this process is “communication and the division of labor.”  Apropos for a book that was five years in the making by Wilson and Holldobler.