Quote:
Originally Posted by Toby_H
In the above quoted scenerio, removing the aa's from the wild population and not removing the aa's in the captive population alters the ratio of big A's to little a's when comparing the two populations...
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This is not the comparison we're making. The wild population has a ratio of A to a (to emphasize my point, we'll say the ratio is wA:wa to indicate that this is the wild ratio of alleles A and a). We pull a founder population from the wild population, so this captive population has the same ratio of A to a (we'll call this cA:ca).
What we want is wA:wa to EQUAL cA:ca. And in this instance wA:wa ONLY refers to the frequency of alleles of the wild population when we collected the founder stock. We realize that the wild population will change, but in a large enough population (and "large enough" can be a very small number of individuals), these changes are slow. Even in small populations, changes are slow if environmental conditions are constant. The ratio of ratios that you're talking about doesn't make sense.
A ratio is a fraction. We want an equals sign in our equation when comparing captive and wild populations. We only use a division sign (ratio) when we compare allele frequencies WITHIN a population (whether it be the captive population or the wild population).
