It is early morning on a wide plain in Amboseli National Park in southern Kenya. With a small Dixie cup and a wooden tongue depressor, Susan Alberts picks up a fecal sample left by a female baboon named Yoruba.
Alberts is an eminent primatologist. She is both the chair of the department of evolutionary anthropology and a member of the biology department at Duke University, and the co-director of the Amboseli Baboon Research Project. But this morning, she has the less-than-glamorous job of preparing Yoruba’s poop.
Alberts carries the cup to her makeshift field laboratory — the hood of a mud-spattered 4×4 — and divides the sample among several cups, marking each with identifying details. She then treats each sample with specific chemicals according to how it will be used. “That’s for Beth,” Alberts says, as she adds some formalin to one of the Dixie cups. Beth Archie is a biologist at the University of Notre Dame and an associate director at Amboseli who heads the project’s microbiome research.
When the Amboseli Baboon Research Project was founded in 1971, microbiome research was not on the radar. The goal was to uncover the deep evolutionary roots of social behavior in primates. Since then, Amboseli scientists have followed thousands of baboons, made many important discoveries about the importance of social bonds, and been published in prestigious scientific journals such as Science and Nature. They have also picked up a lot of baboon poop. For 20 years now, the fecal samples have been used for testing DNA and steroidal hormones.
But about five years ago, those fecal samples, combined with the project’s detailed records of baboon social interactions, revealed a surprising link. Bodies host a wealth of microorganisms, which scientists call the microbiome; fecal samples specifically offer insight into the gut’s microbiome. Scientists had long assumed that the composition of the gut microbiome was largely determined by diet and environment, but the Amboseli samples revealed that a baboon’s social life is an important predictor of this microbiome.
