A bacterium from a boiling Yellowstone spring makes every PCR test possible
Thomas Brock found Thermus aquaticus living in water hot enough to cook an egg, and its enzymes turned out to survive temperatures that destroy ordinary proteins. Decades later, its heat-proof DNA polymerase became the engine of PCR, letting the reaction run unattended through dozens of scalding heating cycles. Nearly every DNA test since, forensic, medical or a home ancestry kit, depends on an enzyme first pulled from a hot spring nobody expected to be useful.