Author looking for help on mutations due to incest, please

[sweetspottina]

Just doing my research...about how many generations would it take before serious, visual mutations would occur due to incestual reproduction between siblings? Thanks for any help!

[Darby]

You don't get mutations from incest.

What can happen is that recessive mutations in a family line that affect genes, usually changing the protein codes to make a non-working protein, can pair in closely-related mates and pass on two non-working protein codes. The recessives can pass along a family line, causing no real problems because they're recessive, and in matings with non-family never combine with a similar allele.

The offspring with both recessives will lose whatever function that protein was supposed to do - if it's an important protein, all sorts of bad things can go wrong. That's why these are often called "lethal genes."

I don't think that you can predict what sort of effects you're going to get, though, because the mutations themselves are random and could affect anything. Could be vision (that's an area where non-lethal effects could be easily detected), but it could be any other system as well.

One weird thing: repeated sibling crosses often remove these "bad" alleles (there's a clear selection pressure against them), so over time (if the first few generations aren't too screwed up) the situation actually improves rather than getting worse.

[sweetspottina]

Darby
Thanks for answering. I'm thinking more like a congenital problem like a cleft palate or fluctuating assymetry issue that would become a familial trait, not necessarily a mutation. Any help is GREATLY appreciated!