New Species Fills Billion-Year Gap in Evolution of Cyanobacteria

On this day in 1796, the physician Edward Jenner administered an inoculation derived from cowpox pus into the arm of 8-year-old James Phipps. Jenner's hypothesis that exposure to the relatively mild cowpox virus conferred immunity against smallpox helped develop the modern-day vaccine.

The 60-Year-Old Scientific Screwup That Helped Covid Kill — All pandemic long, scientists brawled over how the virus spreads. Droplets! No, aerosols! At the heart of the fight was a teensy error with huge consequences.

58-Million-Year-Old Mammal Footprints Found in Wyoming