Modern humans have been interbreeding with Neanderthals for over 2,00,000 years, as per a new study. Researchers identified a first wave of contact about 2,00,000-2,50,000 years ago, another wave 1,00,000-1,20,000 years ago and the largest one about 50,000-60,000 years ago. They used a genetic tool called IBDmix that uses AI to analyse 2,000 living humans, three Neanderthals, and one Denisovan.