Absolutely Dick, I was trained in Genetics and evolution and have often noticed the similarities between inherited traits in biology and the development of traditional music over the generations.

One thing I will add is that the size of a population generally is critical to it's survival - too small and the chance of adapting to it's surroundings is greatly reduced because the chance of a change or "mutation" being beneficial is proportional to the number of organisms existing at the time.

If they are the same, then that means that too few people interpreting folk traditions will make it less likely that the tradition will change in a way which appeals to modern sensibilities and therefore it will thrive less - a vicious circle of decline? That is why I'm of the school of thought that thinks that anyone getting the bug for traditional music is a bonus whether or not you personally like the way they're doing it! I think that the two worst things you can do are a) wrap the tradition up in a bubble and say it cannot be changed because it was collected at one point in history or b) disapprove of anyone trying their arm at folk music if their interpretation doesn't appeal to you at first.

You can take this analogy quite a long way and say that just like the species that have lived virtually unchanged for millenia (e.g. crocodiles), there are traditional works who's very design (whether designed from scratch or evolved over time) means that they have survived virtually unchanged despite multiple passings from mouth to ear.

The only thing that falls down in this discussion is that only in the last 100 or so years have we been able to listen back to the earliest recordings of traditional music - something which was never possible before and certainly slows down the natural evolution of traditional music while people are constantly put under pressure to constantly refer to it as "the right way to go about things"