In a laboratory in Oregon, scientists have reached 160 million years into the past to resurrect the immune defenses of our earliest mammalian ancestors — and found that some of those ancient molecular weapons outperform the ones we carry today. The work centers on lactoferrin, a protein present in nearly every human body fluid, and the antimicrobial peptides it harbors that rupture bacterial membranes. At a moment when antibiotic resistance threatens to unravel a century of medical progress, this inquiry into evolutionary history suggests that nature's long experiment may hold lessons our own