Cultural Evolution

By this definition, culture has proven to be widespread in the animal kingdom. The social transmission system of Norway rats was dissected in a classic series of papers by BG Galef (1988) and his colleagues. Andrew Whiten (Whiten, McGuigan, Marshall-Pescini, & Hopper, 2009), Michael Tomasello (Herrmann, Call, Hernandez-Lloreda, Hare, & Tomasello, 2007) and their colleagues have studied social transmission in apes and humans in a comparative framework. This work shows that chimpanzees are rather good social learners compared to other animals, but humans prove to be much better social learners than our nearest relatives. Human children are compulsive imitators. The quantity of information that humans can acquire by social transmission thus far outpaces that of any other species. Humans can thus build up complex cultural adaptations by cumulating successive innovations to eventually evolve structures and behaviors that rival organic adaptations in their sophistication and diversity. For example, beginning about 11,000 years ago, foraging peoples who harvested wild plants began to experiment with simple schemes for encouraging the plants they targeted (Richerson, Boyd, & Bettinger, 2001). Over the subsequent few thousand years, such experiments eventually resulted in the creation of a diverse set of artificial agroecosystems based upon domesticated plants and animals. Systems adapted to most climates and soils on earth evolved, ranging from root crop dominated systems in the poor soils of tropical rain forests to caribou herding near the Arctic Circle. In favored areas, agriculture led to dense settled populations, intricately adapted agricultural technology, and complex social systems. Humans are the only species we know that is highly specialized for social learning and cultural adaptations. These skills led to a cultural adaptive radiation that bears comparison with the rapid radiations hundreds of new species of fishes in large tropical lakes.