The effort was worth it. Pearson’s results are the first to quantify how the temporal lobe changed in Old World monkeys and suggest that these changes were directly related to changes in behavior.
“I think it is quite correct to suppose that changes in brain anatomy suggest changes in behavior or cognition,” agreed Tom Schoenemann, a Cognitive Science professor in the College who was not involved in the study. “It is just difficult to know precisely the nature of any behavioral or cognitive change,” he said. Schoenemann cautioned that some information is lost when using the skull as a proxy for the brain and that, further, brain morphology can’t always predict an individual’s behavior.
Still, Pearson’s research used advanced methodologies to get as close to understanding morphological and cognitive changes as possible.
"The 3D data processing allows you to do [a study like this] in a much more sophisticated and detailed way,” reflected Polly, Pearson’s doctoral advisor who leads a team of researchers studying vertebrate evolution in the College. “New methodologies address questions in sometimes more meaningful ways,” he said, in this case that of how species adapt to climate change.
Just as Pearson’s Old World monkeys adapted to droughts, temperature changes, and the resulting shift from tropical forests to savannas, organisms will also need to adapt to the environment created by anthropogenic climate change.
“The global temperature could change by 5-10 ºC [...] and there will always be someone who says, ‘that doesn’t matter’,” said Polly. “So, the question is how much does it matter? What reorganizations change? How fast did they change in the past? How much time was there to either become extinct or adapt?”
Pearson’s case study in Old World monkeys offers an example of how one species’ brain reorganized to adapt to a changing environment and may be indicative of a broader trend, suggested Schoenemann.
“This general idea that environmental shifts to more open environments may have led to modifications of brain areas, because of those areas' mediation of particular types of cognition,” he said, “I think is reasonably applied to humans also.”