One kind of domestic cat is the Siamese. All pure-bred Siamese cats are descended from a few common ancestors. Many Siamese cats now have much larger ears, narrower faces, more angular bodies, and slanted eyes than the classic Siamese cats do. Modern Siamese Classic Siamese Image by Chantel Hurlow published under the GNU Free Documentation License Both kinds of cats still exist today. The development of the modern Siamese cat took place over a period of about 30 years. What caused some family lines of Siamese cats to change their appearance from the classic to the modern shape? A. artificial selection B. adaptation C. an increase in genetic diversity D. natural selection