"Around 75,000 years ago, something very odd happened. Genetic diversity imploded, the population bottlenecked and suddenly most species of Homo whathaveyou vanished like the daughter from the first season of Family Matters.
The prevailing explanation is the Toba catastrophe theory, which posits that a supervolcano erupted near Lake Toba in Sumatra. The Toba eruption created an explosion of around 2,000 megatons (more than 150,000 Hiroshima bombs).
The cloud of ash pulled the same trick as the K-T disaster, obscuring the sun and plunging the planet into a volcanic winter. The global temperature dropped up to 10 degrees, which is mind-boggling given that climatologists lose their shit over one and two degree shifts.
... the ensuing havoc resulted in the extinction of every member of the Homo genus save Neanderthals and modern man. Homo sapiens didn't escape unscathed, though--the blast may have reduced the human population to approximately 10,000 people.
Ten. Thousand. People. In comparison, Wrigley Field holds around 40,000 fans. After the Toba event, the entirety of mankind, all the remaining humans in all the world, could be consigned to the bleacher section."
WE'RE ALL INBRED, LET'S HOLD ORGIES