“Something akin to a global scale combustion caused by perhaps a comet scraping our planet's atmosphere or a meteorite slamming into its surface, scorched the air, melted bedrock and altered the course of Earth's history. Exactly what it was is unclear, but this event jump-started what Kenneth Tankersley, an assistant professor of anthropology and geology at the University of Cincinnati, calls the last gasp of the last ice age. 'Imagine living in a time when you look outside and there are elephants walking around in Cincinnati,' Tankersley says. 'But by the time you're at the end of your years, there are no more elephants. It happens within your lifetime.”