Genetic diversity is reflected in the differences among individuals for many characters, including eye, skin and hair colour in humans, colour and banding patterns of snail shells, flower colours in plants, and protein and DNA sequences. For example, diversity among Hawaiian honeycreepers (chapter frontispiece) reflects genetic diversity in their finch-like ancestor. Similarly, the vast variety of dog breeds have all been derived from the gray wolf (Vila et al. 1997). Starting with the wolf, selection based on phenotypes has produced breeds of different size (St. Bernard versus chihuahua), behaviour (German shepherd guard dogs, fox terriers, hunting dogs such as pointers, water hunting dogs such as labradors, sheep dogs, cattle dogs, etc.), shape (bulldogs, dachshunds), etc. These differences reflect both genetic diversity within the ancestral wolf and new mutations that arose during selection.