Orangutan populations develop different cultures just like humans

We know that humans aren't the only species to develop cultures, as other great apes can learn social behaviors and pass them down through multiple generations. Now it appears we all evolved the capacity for culture at the same time.

The term "culture" evokes a lot of lofty concepts - art, literature, history, science - that may seem to be pretty much uniquely human traits. But at its most basic, all culture is simply the combined knowledge of a population, passed down over multiple generations. It's learning that goes beyond instinct and goes beyond simple trial and error. It's knowledge that operates on a larger scale than just a single individual.

Humans are particularly adept at this, of course, but we're far from the only ones. In particular, our great ape cousins like chimpanzees, gorillas, and orangutans have demonstrated clear signs of this sort of cultural processes. One of the most intriguing discoveries came about ten years ago, when researchers noticed that behaviors varied significantly from one great ape population to another.

For instance, there were clear behavior differences in nine orangutan populations scattered throughout Indonesia. Crucially, it appeared that genetic and environmental factors alone could not explain why some orangutan populations were behaving differently from others. Only cultural innovation could fully explain the differences in behavior...at least, that was one hotly contested interpretation. The controversy over the extent of ape culture has raged for the last ten years.

Now anthropologists from the University of Zurich have examined 100,000 hours of behavioral data from over 150 orangutans. Using satellite imagery and other remote sensing techniques to chart the ecology differences between the different populations, the researchers now believe they have definitive proof that the orangutan populations are shaped by culture, not just genetics or environment. While their research demonstrated that those last two were hugely important influences, they couldn't explain all aspects of orangutan behavior.

That's where cultural transmission enters the picture. Lead researcher Michael Krützen explains:

The cultural interpretation of the behavioral diversity also holds for orangutans – and in exactly the same way as we would expect for human culture. It looks as if the ability to act culturally is dictated by the long life expectancy of apes and the necessity to be able to adapt to changing environmental conditions. Now we know that the roots of human culture go much deeper than previously thought. Human culture is built on a solid foundation that is many millions of years old and is shared with the other great apes."

Since the underlying mechanisms of cultural learning appear to be the same in both humans and orangutans, that suggests we all evolved this capacity at the same time - or, more to the point, our common ancestor did. Orangutans are more distantly to us than are chimps or gorillas, and we likely diverged from them thirteen million years ago. That means the basic building blocks of culture have been around for a long, long time.

Via Current Biology. Image by Itshears on Flickr.