Ever wonder what it is about some people that makes them able to run marathons into their 70s? For the first time, scientists have identified a genetic pathway that may regulate the rate at which we age. Building on their research is expected to improve our understanding of how to keep our bodies healthy even as they grow older.

Because people want to live forever, most scientific research on the aging process focuses on longevity, meaning ways to stretch our natural lifespan. What it tends to overlook is age-related behavioral decline, which seems remiss since if we are all going to live forever we’d want to do so with bodies and brains that have remained healthy. Longevity and behavioral aging aren’t necessarily related processes; just because we extend one doesn’t mean the other gets pulled along with it.

Researchers studying nematodes called Caenorhabditis elegans, worm-like creatures about 1 millimeter long, discovered two genes that appeared to have recently undergone a “selective sweep,” genetic editing due to the natural selection process. These particular nematodes are frequently used in anti-aging research because their naturally short lifespan means any changes to longevity are easy to observe. A paper detailing the research was published in the scientific journal Nature.