A groundbreaking discovery is rewriting the story of human evolution, revealing that an ancient human species once thought to be an evolutionary dead end may have left genetic traces in people alive today. By extracting proteins from 400,000-year-old Homo erectus teeth discovered in China, scientists uncovered evidence suggesting that these early humans interbred with Denisovans, another mysterious ancient human group. That genetic connection may have eventually reached modern populations in the Philippines, Papua New Guinea, and other parts of Southeast Asia.