There's an impact meteor hypothesis, disease, super volcano, and the rapid seesaw climate change itself. https://blogs.scientificamerican.com/history-of-geolog

There's an impact meteor hypothesis, disease, super volcano, and the rapid seesaw climate change itself. https://blogs.scientificamerican.com/history-of-geology/httpblogsscientificamericancomhistory-of-geology20110727the-younger-dryas-impact-hypothesis/ https://blogs.scientificamerican.com/history-of-geology/http...