Chimpanzees' Cultural Complexity Increases With More Changeable Environments

[Judi Lynn]

By Stephen Luntz
16 SEP 2020, 17:24

Anthropologists have long suspected our ancestors were pushed into their role as masters of technology when the forests they lived in turned to savannah. This hard-to-prove hypothesis has gained support from a study of chimpanzees, showing our nearest living relatives respond to frequently changing environments by developing wider behavioral diversity.

Fifty-five years ago, the discovery chimpanzees made tools shocked the world. Today, we know that not only do they use a variety of tools but many are specific to certain populations. The same is true of behaviors – some chimpanzees escape the heat in caves or by bathing, while such activities are unknown to others. These are cultural traits, passed on from adult to child within certain groups but unknown in others.

An international team of researchers led by Dr Ammie Kalan of the Max Planck Institute for Evolutionary Anthropology tested the influence of the environment on chimpanzee behaviors. Inevitably, some behaviors only evolve under specific conditions – methods for extracting a food source will not be preserved long when living where that food is absent. The team wanted to know if all chimpanzee populations have a similar number of options in their toolkit or if certain environments inspire a larger array of distinctive behaviors. In particular, the team note in Nature Communications that this would test “the critical assumption that population diversification precedes genetic divergence” and the formation of new species.

Using a combination of their own observations and data from other researchers, Kalan and co-authors investigated whether 31 behaviors, such as nut-cracking and termite-fishing, are present or absent in 144 chimpanzee populations.

More:
https://www.iflscience.com/plants-and-animals/chimpanzees-cultural-complexity-increases-with-more-changeable-environments/