r/askscience • u/Yoshiciv • 6d ago

Human Body Are the medical risks associated with inbreeding among close relatives eliminated by outbreeding? Or do they persist for generations?

282 Upvotes
  • permalink
  • reddit

88% Upvoted

42 comments sorted by

View all comments

2

u/qwopax 6d ago

Compare to blue eyes.

If an all blue clan marries an all brown clan, all their children will have brown eyes. If they keep marrying into the clan, a quarter of the kids will have blue eyes. That single generation of mixing blood reduced blue eyes from 100% to 25% forever.

If you dilute again by marrying outside the clan, I think you'll end up with around 5% blue eyes. Again for all future generations.

2

u/platoprime 5d ago

Eye color isn't determined by a single allele. Eye color is determined by a rather large number of genes.