A species of bird on the mainland can have gray, blue, or black plumage. A few gray and blue birds land on a ship and are carried past an island, which they land on and settle. The resulting population of birds is only gray or blue, as no alleles for black plumage came to the island. What is this an example of? A. Population bottleneck B. Hardy-Weingberg principle C. Genetic drift D. Founder effect