scientists have long been interested in differences between dogs and wolves in their social behavior toward humans. dogs and wolves share a common ancestor. in trying to understand the differences, a researcher analyzed data collected from 18 domesticated dogs and 10 wolves that had been raised by humans. if she discovered that the degree of social relationship a dog exhibited toward humans was positively correlated with a chemical modification of a part of a chromosome rather than what alleles a dog had, this would be an example of .