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Old 09-19-2006, 02:13 PM   #11
toyah
Quote:
Originally Posted by bill38112
All modern animal husbandry is based on inbreeding. Basically all the food sources we have all heavily inbred. That's why we have turkeys so heavy they can't fly and cattle that are nearly twice the bulk of their ancestors. It's a good thing. But food animals are not bred for longevity. Hopefully pet animals are.
The examples you cite are not because of inbreeding - they're because of human selection, and one of the methods of selective breeding is inbreeding. A nit-picky distinction, but an important one all the same. Careful inbreeding can also be used to extend lifespan though - it all depends what you're selecting for.

Quote:
Originally Posted by bill38112
By definition developing new morphs requires inbreeding. What I haven't seen discussed here is "Hybrid Vigor" or the tendency that multi generation inbreeding results in smaller, weaker, less healthy specimens. I bred dogs, cats, birds, and fish before acquiring the snakes. All of those species showed the negative effects of inbreeding after five generations.
Hybrid vigor is the absolute opposite of inbreeding depression (which is what you describe), and inbreeding depression has been mentioned in this thread already. I disagree that after five generations you necessarily can see the negative aspects of inbreeding - do you mean five generations brother x sister, or looser breedings than that - and if the matings are not as close as bro-sis then how can you decide it definitely causes problems after five generations?