This message is from: "Katherine Carter" <[EMAIL PROTECTED]>
The article that Ruth cites about animal population genetics and the need to maintain a large gene pool is a good one. My own work is in population genetics of domesticated plants, where the same problems can occur. A very general rule of thumb that we use is that the size of the "effective breeding population" should be at least several hundred individuals (it should probably be significantly more for animal breeds which one wants to remain viable for many, many generations). Remember, this number refers to the "effective" breeding population, those individuals that are actually producing offspring (not to the total population number); and the calculation of the "effective" number is reduced if some individuals (usually sires) are used to a disproportionate extent. Fortunately the NFHR prohibits registration of inbred individuals, but one should still be aware of the "effective breeding population" which is a somewhat different issue. --Kathy in Maine
