In 1878, Fritz Müller (1821–1897), a German-born zoologist, described a phenomenon in which a group of species with the same adaptations against predation was also of similar appearance. This phenomenon is now called Müllerian mimicry; such mimics include wasps and bees, all of which have similar yellow-and-black-striped patterns that serve as a warning to potential predators. In 1861, Henry Walter Bates (1825–1892), a British naturalist, proposed that a nontoxic species can evolve (especially in color and color pattern) to look or act like a toxic or unpalatable species in order to avoid being eaten by a predator. The classic example is the viceroy butterfly, which resembles the unpalatable monarch butterfly—an adaptation called Batesian mimicry. However, it has more recently been proven that the viceroy is actually a Müllerian mimic, since it seems to be unpalatable to birds, too. Bates was also a colleague of Alfred Russel Wallace, and it was Bates who introduced Wallace to botany and field collecting of animals and plants (for more about Wallace, see above).