Evolving finches??

Don't think of it as a deliberate change.

In a population, there are a number of versions of any given gene floating around. Plus, in each generation, there will be a number of mutations that will change some of these genes. Finally, there is generally a more complex relationship than a simple one gene / one feature relationship.

The net result is that when you look at a feature like beak size, there will be variance in a given generation due to the way all of the variety of genes interact.

Now in some situations, birds with a larger or smaller beak may have an easier time making them more likely to survive and passon their particular combination of genes.

So if such a selective pressure exists, then there may be a change in the size distribution of beaks in the next generation. THis is just what has been described.

I would not lose any sleep over this if I were you. While this does fit in well with evolution, most YEers are also convinced that such changes really do happen and have thus incorporated such small changes within populations as being normal.

Now if you want to get into where YEers think that the diversity of a given gene in a population came from or what the boundary preventing small changes from adding, then they have a harder time.

But don't worry over just a changing beak size. Nearly everyone accepts that such happens regarless of what side they choose in the larger debate.

 

I dont' think inter species adaptation is the same as evolution. Pugs used to be nearly 80 pounds at one point not too long ago. They are 12 - 15 pounds now because of breeding and environment of the animal.

 

As a YEC, let me answer your question.

The animals already have the information for the different beak sizes in their population. Natural selection is simply what determines which sub-population gets expressed as the majority.

 

Long time no see.

Now the question for you is how would a population get more than four alleles of a given gene into the population since I know that you deny the ability of mutation to produce new and useful genes?

 

I mean the genes for large and small beaks existed somewhere in the population, yes. The birds have no capability of determining which are esxpressed, but rather nature selects the ones in the population with the greatest survivability. Natural selection has no ability to 'create' new information, but only select from existing information.

I've been busy with work and the fish in the lakes around my house don't catch themselves!

There is a problem with the question. You assume that one gene controls the size of the beak. In fact, many genes would make up a beak, so there would be quite a continuum of factors in beak size. Additionally, many other factors in the bird may effect the beak size. For example, perhaps the gene that tells the beak when to stop growing is damaged. Perhaps the genes that control the rate of growth are damaged. Perhaps the genes that control the flow of raw material to the beak for construction are not operating properly. All of these genes can potentially effect the beak size... so the variation is MUCH greater than 4 alleles.

 

No, I took this in to account. From my first post.

Since no one has done gentic testing on these finches that I am aware of, we don't know what the case is for this particular case.

But the question was more general. Where we do have genetic testing, we sometimes find multiple alleles in a given population, sometimes hundreds. These must have had an origin. But it is difficult for YEers who insist on no good mutations to explain the origin of these extra alleles.