Unlike other domestic species which were primarily selected for production-related traits, dogs were initially selected for their behaviors. In 2016, a study found that there were only 11 fixed genes that showed variation between wolves and dogs. These gene variations were unlikely to have been the result of natural evolution, and indicate selection on both morphology and behavior during dog domestication. These genes have been shown to have an impact on the catecholamine synthesis pathway, with the majority of the genes affecting the fight-or-flight response (i.e. selection for tameness), and emotional processing. Dogs generally show reduced fear and aggression compared to wolves. Some of these genes have been associated with aggression in some dog breeds, indicating their importance in both the initial domestication and then later in breed formation. COUNT 9
QSN1 Instead of genetic traits for production, dogs are bred for what? ANS1 behaviors. QSN2 How many "fixed" genes demonstrate the differences between the wolf and dog? ANS2 11 QSN3 The gene differences indicate what two things done by selection in dogs during breeding for domestication? ANS3 morphology and behavior QSN4 What is the common trait selected for dogs in overall breeding? ANS4 tameness QSN5 What do most dogs show less of than wolves? ANS5 fear and aggression QSN6 Most domestic animals were selected for what traits? ANS6 production-related traits QSN7 Why were dogs initially selected? ANS7 for their behaviors. QSN8 For wolves and dogs, how many fixed genes show a variation? ANS8 11 QSN9 Dogs show less fear and what as opposed to wolves? ANS9 aggression