The recent discussions on gene pool size have had some statements made that can obscure the real situation. A distinction has to be made between potential and reality. For example, a statement was made that a large research oriented breeder may have more breeding animals but a smaller gene pool. That could happen, but it is not realistic. We have a large lab mouse breeder in our state and they produce very homogenous strains of mice (a requisite for validity). However, the demand for any particular strain is small, so they have hundreds, if not thousands, of specialized strains. Thus, the facility has access to a large gene pool even though a given line may have little variation. While animal research is not a favored topic here, the needs of these people are very varied and specific, so any research breeder that only had a small number of strains would go out of business for lack of demand. This discussion is obviously directed at one particular ferret breeder and this breeder has more color lines and other characteristics than any other source I'm aware of. So lets not damn an operation because of what could be, even if that isn't realistic. Another potential that was mentioned is that a smaller breeder with a wide source of ferrets can have a larger variability in genes. Again, this can be true to start, but limited breeding can eliminate these and lose the wide potential quickly. If the animals don't produce enough offspring, all their genetic potential may not be passed on. A small breeder may start with a good gene pool, but the low number of offspring may limit the gene variation in each succeeding generation. This is how isolated populations get homogenous. We've heard about deer mouse strains that can't interbreed. How did that happen? Genetics is a probability game, and the odds for expression are not uniform. For any probability prediction, it's accuracy is limited to predicting the outcome of a large number of trials, not individual events. So for a range genes to be expressed in succeeding generations, large numbers of offspring are required, or constant infusion of outside genetic material. If a group has 20 genes for some characteristic, but only 8 offspring, how many get transmitted? How do you think ethnic characteristic in humans came about? Even with the genetic potential, the low birth/survival rate winnowed down the potential even in large geographic areas. Suddenly, a group has distinctive hair color, eye color, cheekbones, height, etc. even though the whole human race has many more possible types. When you throw in the recessive, dominant and incomplete dominance of genetic traits, the picture gets more muddy. A recessive trait can be passed along and express itself generations later after having "disappeared." I've seen a number of people express interest in horse racing. On a Nova program a few years back, they contrasted the lack of change in time records in horse racing versus human track events. They stated that all current race horses in the US can be traced back to 5 horses imported in colonial times (I accept their statement as true, I don't care enough to check it out and consider them a credible source). The lack of genetic variation has produced a fairly standard horse and their speeds have not improved much over this century. Track events have shown a tremendous change, even in the years before training method improvement became emphasized and a factor. One explanation is the huge variation in human genetic makeup creates different capabilities. The point underlying all this is that hypothetical constructs can be made to explain all sorts of outcomes. Testing them against results has to be done before they can be accepted. A small breeder could have a larger gene pool than a large breeder if certain constraints are accepted. However, these constraints are not the reality. Many small breeders concentrate on producing specific traits. Their ads state so. I don't see all that much emphasis on producing variation, but creating certain packages of desirable traits and then locking them in. Just because small breeders introduce new stock, they do so often with a specific purpose. They choose what to introduce. This is not the random breeding that produces wide genetic variation. ( )--(a) (@=@=) \ Till next time.......Rudy the ferlosopher O__) \ \___ \ \ /\ * ) \ [Posted in FML issue 1534]