Developing a hypothesis on the “domestication syndrome” of animals

The domestication of many animal species was a key element in the development of human societies. An early step presumably involved the acquisition of docility, a prerequisite for animal handling, training and controlled breeding. Unexpectedly, however, domestication entails the acquisition of an additional suite of physical and behavioural traits whose connections to each other and to docility are completely unclear. This collection of associated traits has been called the “domestication syndrome”. Together with STIAS Fellow Richard Wrangham (Harvard), a hypothesis has been developed that might explain this phenomenon. It is proposed that its principal developmental roots lie in a mild neurocristopathy, that is, a partial depletion of neural crest cells from key sites during embryonic development. A paper has been written in which the evidence is reviewed and arguments made to show that the physical traits of the syndrome follow directly from the proposed neurocristopathy while the behavioural ones are indirect consequences of diminished neural crest cell numbers on the formation of the forebrain.