A new study suggests Southern California's major fault system is more stressed than at any point in the last 1,000 years. Researchers found that the Cajon Pass, where the San Andreas and San Jacinto faults meet, could act as an “earthquake gate” that determines whether a future rupture spreads across both faults. Current conditions resemble those that preceded some of the region’s largest historical earthquakes.

Plague was already a deadly killer 5,500 years ago, long before cities, farming, or the rat-infested conditions usually linked to historic outbreaks. By analyzing ancient DNA from hunter-gatherer cemeteries in Siberia, researchers discovered early plague strains in nearly 40% of the individuals studied and found evidence of rapid family-based outbreaks that wiped out many children and young teenagers.

A new theory suggests the universe is constantly recording its own history in the fabric of spacetime. If correct, this cosmic memory could help solve some of the biggest puzzles in physics, from black holes to dark matter and the universe’s ultimate fate.

A new study from Northern Arizona University is raising red flags about a widely used global emissions database from Climate TRACE, a consortium co-founded by Al Gore. Researchers found that the database may be dramatically undercounting carbon dioxide emissions from cars and trucks in cities—by an average of 70% across 260 U.S. cities, with some cities showing gaps of more than 90%.

Scientists have taken a surprising step toward unlocking regeneration in mammals, showing that the ability to rebuild complex body parts may not be lost after all—it may simply be switched off. Using a two-stage treatment, researchers redirected the body’s normal healing response away from scar formation and toward regrowth, successfully restoring bone, joints, ligaments, and tendons after amputation in animal studies.