Eruption early in human prehistory may have been more whimper than bang
By Erin Wayman
If Hollywood’s right, the apocalypse will be brutal. Aliens, nuclear war, zombies, plague, enslavement by supersmart robots — none of them are good endings. Some archaeologists, however, believe an apocalypse has already come and gone. About 75,000 years ago, they say, a monster volcanic eruption nearly wiped out humankind, leaving behind only a few thousand people to repopulate the world.
The explosion of Indonesia’s Toba volcano was the largest eruption of the last 2 million years. The volcano coughed up some 2,000 to 3,000 cubic kilometers of ash, enough to fill almost three-quarters of the Grand Canyon. Unleashing hordes of light-blocking particles, an eruption that size should have cooled the planet and reduced rainfall, killing off plants and creating food shortages.
Archaeologists recognized in the late 1990s that the disaster might explain a population bottleneck recorded in modern people’s DNA. Genetic evidence indicates that the human population drastically declined and variation in the gene pool plummeted around the same time Toba exploded.
The story sounds neat and tidy. But researchers are still trying to verify whether our species’ near-extinction experience was fact or fiction.