A latest study in Spain showed that, human was the ultimate "killer" causing the extinction of mammoth. However, climate change also played a "leading role" in this "death game". About 12,000 years ago, the mammoth population began to decline sharply until it completely disappeared 3,600 years ago. What was the reason for the final extinction of mammoths? The scientific community has been arguing about this for a long time. David Nogues-Bravo of the National Museum of Natural Sciences in Spain