https://thenextweb.com/syndication/2020/02/19/research-early-humans-in-africa-may-have-interbred-with-an-unknown-species/

One of the more startling discoveries arising from genomic sequencing of ancient hominin DNA is the realization that all humans outside Africa have traces of DNA in their genomes that do not belong to our own species.

The approximately six billion people on Earth whose recent ancestry is not from Africa will have inherited between 1% and 2% of their genome from our closest but now extinct relatives: the Neanderthals. East Asians and Oceanians have also inherited a small amount of ancestry from the Denisovans, another close relative of Homo Sapiens.