Cheetahs are basically all the same. Any two randomly selected cheetahs will be so similar genetically that a skin graft from one will likely provoke no immune response in the other. In the distant past, cheetahs underwent a population bottleneck—an evolutionary event in which a species nearly dies out and is repopulated by a few individuals whose genes are then disproportionately reflected in the ensuing generations. All humans can trace their ancestry back to a single woman. When did she live?
John Quincy Adams
Back in the day
Though the Roman Emperor Diocletian ordered the persecution of Christians several times, his so-called Great Persecution began with an official edict. Churches were razed, scriptures burned, and practitioners executed. A few years later, he became the first Roman emperor to voluntarily abdicate, after which he retired to Croatia to grow cabbages in peace. The reign of Constantine soon made Christianity the empire's preferred religion. When asked to return to the throne, how did Diocletian reply?
Born on a day like today
The mechanically gifted 10th child of a French glove-maker, Vaucanson created some of the world's first robots. His famous gold-plated "Digesting Duck" had hundreds of moving parts and could eat, drink, and defecate. In 1745, weavers pelted Vaucanson with stones when he created the first fully-automated loom, which utilized punch-card technology. Decades later, his ideas would prove pivotal to the Industrial Revolution. How many songs could his mechanical flutist perform?