About 74,000 years ago, the Mount Toba volcano erupted on what is now the Indonesian island of Sumatra. The eruption caused a worldwide environmental disaster. It may have destroyed ancient human populations in many parts of the world. But experts say some groups may have survived the disaster unharmed. Earlier this month, scientists announced that they had found tiny pieces of volcanic glass from the Mount Toba eruption. Their discovery, however, was 9,000 kilometers away on South Africa’s southern coast. Some researchers believe the eruption may have caused world temperatures to drop causing a so-called “volcanic winter” that lasted for many years. Scientists suggest this cold period damaged ecosystems and reduced food resources for people around the world. But, the researchers in South Africa found evidence that the hunter-gatherers there continued to thrive.