The dog was the first domesticated animal. Domestication is an “evolutionary process [that] has been influenced by humans to meet their needs” (Secretariat, 1992, p. 3). In other words, domestication of a species causes biological changes over generations through selection by humans for favorable traits (i.e., traits that are useful, valuable, aesthetically pleasing, etc.).
Domestication led to extraordinarily large changes in the behavioral characteristics of domestic dogs, as well as in their physical characteristics (which is obvious when one compares the many breeds of dogs). Scientific research on the evolution of dog behavior began in the mid-1800s, most notably in the work of Charles Darwin (Darwin, 1872). In the middle of the twentieth century, a deeper understanding of the evolution of dog behavior was gained by combining behavioral analyses with classical genetic analyses of dog breeds (for a review, see Scott & Fuller, 1965).
Over the past 20 years, archaeological discoveries in combination with the results of highly sophisticated genetic analyses have shed a great deal of light on the evolution of domestic dogs (for a review, see Larson, Karlsson, Perri, et al., 2012). For example, there now is little doubt that domestic dogs evolved from the gray wolf, which is found in many parts of Europe and Asia (Honeycutt, 2010; Wayne & Ostrander, 2007). In fact, domestic dogs (Canis lupus familiaris) are considered to be a subspecies of the gray wolf (Canis lupus lupus). This means that, although dogs and wolves have physical features that often are very different, they can mate and produce fertile offspring.
Nevertheless, there still is much controversy about when and where domestic dogs originated. These disagreements are focused on the answers to two questions: when did domestic dogs “split” from gray wolves and where did this happen? These questions have proved difficult to answer because the results of genetic and archaeological research are complex and, hence, very difficult to interpret.
Genetic research on differences in DNA sequences have led to a wide range of estimates about when dogs and wolves first diverged: sometime between 20, 000 to 100, 000 years ago. One reason for the wide variation in these estimates is that dogs and wolves probably continued to interbreed, not only over long periods of time but also in many locations (Vilà, Savolainen, Maldonado, et al., 1997).
The term psychogenetics was introduced by Calvin S. Hall in his seminal book chapter on behavior genetics (1951). The term enjoyed some limited popularity in the 1960s and 1970s. However, it disappeared from usage in favor of "behavior genetics".
