The Iroquois kidnapped new genes
In Octavia Butler’s Dawn (Lilith’s Brood), an advanced star-faring species engineers itself to such “perfection” that it must kidnap other beings (including humans) to obtain their “imperfect” genes. Would humans ever do such a thing?
Before colonization, the native American population (who actually traveled the farthest from Africa) were the least diverse genetically, the most “clonal” continental group. Their low diversity, especially in immune genes, partly explains why the natives fell so rapidly to smallpox and other introduced diseases. Interestingly, some addressed the problem as Butler’s species did: They kidnapped “outsiders.”
The most adept at adoptive diversity were the Iroquois. When an Iroquois community lost too many members to disease, they raided their neighbors (other tribes, or else Europeans) for captives to “replace” their lost siblings and children. The raids were no picnic; but then, European colonial life was so wretched (try being an indentured servant) that some colonists joined the Iroquois voluntarily. Adoptees were quickly married off, thus contributing their disease-resistant genes.
Where else have we sought adoptive diversity? Either amongst humans, or in breeding our animals and plants?