According to natural selection, animals with useful traits are more likely to survive and reproduce. But can social groups also influence an individual’s evolutionary success? This is a long-debated concept known as multilevel selection.
“I think the easiest way to think about it is to think about it in our own terms … and say, I have direct friends, and those friendships impact how happy I am. They impact how productive I am," said Conner Philson, the lead author of a new study from the Rocky Mountain Biological Laboratory (RMBL) that provides evidence for multilevel selection. "But I'm also a member of groups. I have a work group, I have a friend group. And those groups, and the structures of those groups, will also impact me."
Philson is currently the executive director of the UC Santa Barbara Natural Reserve System, but he says he was “once, previously, a marmoteer.” As a PhD student, Philson worked on a long-term study of yellow-bellied marmots in the mountains of Colorado.
“We call ourselves marmoteers, which is, you know, going out twice a day, for six days a week, for five months, watching marmots do stuff. … Which is a lot of data, and that's the kind of stuff you need to ask these questions,” Philson said.
Yellow-bellied marmots are a species of large ground squirrel that live in the Rocky Mountains and the Sierra Nevada in North America. They live in social groups that can vary in size between 3 and 35 individuals.
To understand whether marmots’ groups affected their survival and reproduction, researchers analyzed decades of data. Their results show that these marmots had higher survival and reproductive success when they were part of a group, but a loosely connected one.
“I think the RMBL Marmot Project really is a success story in how important long-term research is," Philson said. "Because otherwise, we wouldn't be able to ask a lot of these questions about evolution and about natural selection."
This project has operated continuously since 1962, making it the second-longest study of individually identified mammals in the world, after Jane Goodall’s primate research.
“I don't think the lay public know that all around them there's these incredible long-term projects happening, and how when we put many of these long-term data sets together, you can learn even more things about the world,” Philson said.
