The Evolutionary Change Under Strong Selective Pressures

1257 WordsDec 13, 20166 Pages
Domestication is a phenomenon that has promoted significant evolutionary change under strong selective pressures (Driscoll et al. 2009). As a result of this phenomenon, various domesticated strains of flora and fauna have significantly contributed to the development of human civilization (Morey 1994; Driscoll 2009). Although it was a substantial component to our progress, it was not until the research of Dmitry K. Belyaev that we began to unravel the early stages of domestication. Assuming that these initial stages involved selection on behavior, Belyaev conducted an experimental study that placed strong selective pressures on tamability. Using the fox, Vulpes vulpes, as a model, this artificial selection developed an experimental population that expressed behavioral, morphological, and physiological characteristics of domesticated species (Belyaev 1969). Under stressful conditions, animals have the tendency to engage in avoidance responses to promote their chances of survival (Smith & Vale 2006; Ranabir & Reetu 2011). These avoidance responses, including fearful and/or aggressive behavior, also tend to be the primary reactions to human encounters. Belyaev suggested that as a consequence, social interactions in the early stages of domestication likely depended on animals with an inhibited response to stress. Ergo, he reasoned that selectively breeding animals expressing this behavioral response, or tamability, would likely mirror these early stages (Belyaev 1969). In
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