Orangutans in Sumatra are more culturally diverse than orangutans in Borneo. They are also more clever and boast bigger brains. Photo by Christiian Conradie and Caroline Schuppli
June 3 (UPI) -- According to a new survey, cultural lifestyle changes inspire evolutionary adaptations more often than previously thought.
One of the best examples of a cultural change with evolutionary impacts is the development of dairy farming. The increased production of animal milk for human consumption inspired genetic changes in milk drinkers.
Genes responsible for lactose tolerance became common in populations where milk consumption was common. The same genes are rare among non-dairy cultures.
Authors of a new study on the subject, published this week in the journal Nature Communications, found "gene-culture co-evolution" isn't unique to humans. Cultural changes, scientists determined, also trigger evolutionary changes among other animals, including killer whales.
Researchers found different killer whale clans have adapted unique jaws and digestive systems to help them catch, process and digest different prey species.
The hunting strategies and prey preferences of older killer whales are taught to the next generation. As a result, a cultural lineage forms among clans. These distinct dietary preferences trigger evolutionary changes among whales, just as they do among humans.
Scientists surmise the evolutionary effect is great enough to drive species' divergence. As a result of cultural differences between clans, killer whales could be in the process of splitting into different species.
Researchers suspect cultural differences can also drive brain evolution. Orangutans in Sumatra, which demonstrate greater cultural diversity, have bigger brains and are smarter than orangutans in Borneo.
The new survey determined gene-culture co-evolution is most common among birds, dolphins, whales and primates.
"There is even evidence that the cultural traditions of one species can drive the evolution of another," Andrew Whiten, professor of psychology and neuroscience at the University of St. Andrews, said in a news release. "Reed warblers, for instance, learn to recognize cuckoos as brood parasites by attending to the alarm calls of other birds, a knock-on consequence of which is that natural selection favors cuckoos with unusual plumage patterns."