Complex sentence: Domestication has involved selection for behavioral characteristics that characterize young animals so, since "behavior is rooted in biology", domestication has resulted in an array of similar neotenous physical traits having arisen in various domesticated animals.
Split into simpler sentences: Domestication has involved selection for behavioral characteristics that characterize young animals. Because "behavior is rooted in biology", domestication has resulted in an array of similar neotenous physical traits having arisen in various domesticated animals.