Can you be 20% (genetically) of something?

[TroutMan]

I think you’re missing that the original 64 are all the ancestors - there are no additional spouses being brought in.

[Colibri]

@tdn

What I’m trying to say (and badly, I must admit), is having 64 great great great great grandparents of a certain racial mix is no guarantee that the last resulting child will have that mix. Those 64 will have 32 children with more or less that mix, but then you’d have to bring in 32 new spouses, and who can tell what they are? You’d have to control the racial makeup of every new spouse for every generation to get the 20% mix.

As has been said, the 64 include the ancestors of all the spouses.

Descendant
2 parents
4 grandparents
8 great grandparents
16 gg grandparents
32 ggg grandparents
64 gggg grandparents

[bup]

@K364

Genetic makeup seems to me to be in powers of 2, which is never dividable by 5.

Even if there is inbreeding among your ancestors, the divisor is still 32 or 64 or 128 depending on how many generations you want to go back.

You are correct.

There is no number of fractions that are powers of two that you could add to get 1/5.

5 and every power of 2 are relatively prime.

[EdwardLost]

If you mean genetically, it would only be possible if the number of genes you have is a multiple of 5.

[tdn]

@Colibri

As has been said, the 64 include the ancestors of all the spouses.

Descendant
2 parents
4 grandparents
8 great grandparents
16 gg grandparents
32 ggg grandparents
64 gggg grandparents

D’oh! Thanks for explaining it graphically.