Humans are probably the only species on Earth that actively fantasizes about its own extinction — and definitely the only one that actively participates in it. Even that whole thing about lemmings running off cliffs is a myth, but we bald-ish primates not only turn existential doom into entertainment (consider the entire post-apocalyptic genre writ large) or religious movements, we constantly invent new ways to derail our global society and put all of us at risk of mass death.
The latest serious entry to this category is artificial intelligence, which isn’t actually intelligence, nor does it reflect a brand new fear. But the dramatic advancements made in AI over the last several years has finally made it something that scares people almost as much as nuclear weapons or the hand of God. Will AI truly become an agent of mass destruction? Nobody actually knows, but that isn’t stopping people from making some outlandish bets.