Modern humans outside Africa have 2 -- 4 % Neanderthal alleles in their genome .
Some Melanesians have an additional 4 -- 6 % of Denisovan alleles .
Modern humans outside Africa have 2 -- 4 % Neanderthal alleles in their genome , and some Melanesians have an additional 4 -- 6 % of Denisovan alleles .