The answer is in their genes—especially those that encode for basic life functions, such as metabolism. Thanks to the lowly C. elegans worm, we’ve uncovered genes and molecular pathways, such as insulin-like growth factor 1 (IGF-1) signaling that extends healthy longevity in yeast, flies, and mice (and maybe us). Too nerdy? Those pathways also inspired massive scientific and popular interest in metformin, hormones, intermittent fasting, and even the ketogenic diet. To restate: worms have inspired the search for our own fountain of youth.

Still, that’s just one success story. How relevant, exactly, are those genes for humans? We’re rather a freak of nature. Our aging process extends for years, during which we experience a slew of age-related disorders. Diabetes. Heart disease. Dementia. Surprisingly, many of these don’t ever occur in worms and other animals. Something is obviously amiss.

In this month’s Nature Metabolism, a global team of scientists argued that it’s high time we turn from worm to human. The key to human longevity, they say, lies in the genes of centenarians. These individuals not only live over 100 years, they also rarely suffer from common age-related diseases. That is, they’re healthy up to their last minute. If evolution was a scientist, then centenarians, and the rest of us, are two experimental groups in action.