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Kathryn A. Lord, Greger Larson, Robin G. Allaby, Elinor K. Karlsson

We recently provided a new definition for domestication as 鈥渢he process in which nonhuman populations adapt to an environment created through human activity鈥� (). It brings domestication fully into an evolutionary framework, obviates the need for assumptions about how domestication occurred, and can be applied equally to plants, animals, and microbes.

In response, Kohl () argues that our definition does not recognize domestication as a 鈥渟pecial case of evolution.鈥� However, as we describe in our article, extensive literature demonstrates that under modern evolutionary theory, domestication is not a special case of evolution, contrary to views held by many scientists in the 19th and early 20th centuries. Our observation that a population can change its relationship to the anthropogenic niche as a result of environmental shifts is fully consistent with this framework. As R. A. Fisher noted in The Genetical Theory of Natural Selection (), 鈥渇itness may be increased or decreased by changes in the environment.鈥� Because evolution by natural selection proceeds through changes in fitness, alterations in the environment, like genetic change, are integral components of the evolutionary process.

Kohl states that the terms 鈥渟elf-sustaining鈥� and 鈥渉uman-created鈥� are arbitrary. Self-sustaining is a key concept in population biology () that is also fundamental to the definition of obligate synanthropes. If a population is not self-sustaining, then it is a sink population that requires immigration to persist and by definition maladapted (). Populations that are adapted to a human-created niche therefore must be self-sustaining, which makes the concept a critical component for the identification of such populations. Similarly, our definition specifies "an environment created through human activity" as distinct from the human body itself, since organisms adapted to live on or in the human body are not necessarily domestic and the evolutionary processes required to thrive in anthropogenic environments differ from those required to survive on the human body.