Use the example in the passage and explain how dogs initially may have evolved, through natural selection, from an extinct grey wolf species.

Here are the answers to your questions:

3.4.1 Initially, within the extinct grey wolf population, there was variation in the amount of amylase produced, with some individuals producing more than others. As these wolves scavenged human food, which was increasingly starchy, those wolves that produced more amylase were better able to digest the starch, gaining more energy and nutrients. This gave them a survival and reproductive advantage over wolves that produced less amylase. These advantageous traits (higher amylase production) were then passed on to their offspring. Over many generations, through natural selection, the frequency of the gene for higher amylase production increased in the population, leading to the evolution of domesticated dogs that are highly adapted to a high-starch diet.

3.4.2 All breeds of domestic dogs belong to the same species because they can interbreed with each other and produce fertile offspring. This ability to successfully reproduce and have viable, reproductive descendants is the defining characteristic of belonging to the same species.