Ancient humans had sex and interbred with a mysterious group known as the Denisovans more than once, new research has found

• We've known for a long time that early humans interbred with Neanderthals and Denisovans, other early hominin species that co-existed with Homo sapiens.• A new study indicates humans interbred with Denisovans more than once, showing that there were more interactions between these early hominin groups …