As waves of humans left Africa tens of thousands of years ago, eventually populating the entire planet, they were joined on their world-conquering ride by the trillions of microorganisms that compose ...

HAMBURG — For more than two decades, Herman Pontzer, professor of evolutionary anthropology and global health at Duke University, has studied human metabolism and energy expenditure, especially in ...

Some types of bacteria living in the human gut may have accompanied our ancestors for tens of thousands of years. As people moved across the world and raised families, they appear to have passed these ...