Per David Reich: >10-20% of the ancestors of Eurasian people are neanderthal

West African populations have up to 19% "Ghost DNA", belonging to an extinct species their ancestors interbred with

Southeast Asians have DNA of the extinct Denisovan species, as much as 3-5% in the aboriginal people of Papua New Guinea, Australia, the Philippines

These aboriginals also have DNA belonging to a now extinct, but not yet discovered hominid species

I'm sure the implications of all these findings have not yet been discovered but it's exciting to see them explored