Actually they don't. Change means to change one thing for another. Alter meant to change soemthing already in existence.
The mutation of an albino did not change something and give it skin, it altered the skin it woudl have gotten without the mutation.
OK! now you have defined a difference between change and alter. We can work with that. To alter is to change the details without changing the essesnce To change, in this context, means to change the essence. Fine.
Now that we agree, on the distinction, How does a mutagen tell the difference between a mutation that alters a gene and one that changes a gene? And what prevents the mutagen from making the second kind of mutation?
The bottom line is that mutations cannot change a species into a different species.
Let me finish my comments on your definition of "alter" and I'll be right with you on this, along with your final paragraph
If you want to use "change" and "alter" the same way fine.
No, I'm fine with non-standard definitions in order to make a distinction. I have used them myself in other arguments, for example making a distinction between "gay," the orientation and "homosexual," the so-called "lifestyle."
I just ask that you acknowledge that it is non-standard and define the distinction. Now that you have, no problem. I will point out, however that both you and I had to resort to a more generic sense of "change" in order to put the distinction into words.
I have not denied anything except mutation are a mechanism for evolution. Do you have any evidence that anything in the paragraph above has resulted in a change of species?
That's fine. Have a nice day. I would like you to provided the evidence that mutations, and take as many as you like, have ever resulted in a change of species. If you can't do that then what you have said is nonsense as far as mutations being a mechanims for evolution is concerned.
Mutations alone do not drive evolution. Mutations merely increase the amount of variation in the population. Mutations that change the genes also make interbreeding slightly more problematical. So slightly that the difficulty of breeding a specimen with a small number of changed genes is unnoticible.
Selection favors one trait over others in survivability, fertility, or mating opportunity. Each generation more individual have the selected trait, and less have the unselected traits. If you have different sub-populations being selected for different traits, then given enough generations, you will end up with different breeds. At this point, they are still all the same species, the same kind.
But this is where those slight difficulties in breeding crop up. Within each sub-population, the same changes accumulate, so they all have the same changed genes, which match up and present no barrier to breeding, but between breeds, different changes accumulate, so it becomes more and more difficult for one breed to breed with a different breed. At some point, the difficulty has become great enough that cross-breeding is impossible. However each breed can still freely breed within itself. The greater group changes from a population of one species, with sub-populations of various breeds to a collection of separate populations that can't crossbreed.
The mechanism that you are looking for, therefore, is the very "change" that you dismiss as impossible without looking at the evidence, or giving a mechanism to explain the "impossibility." I have asked you repeatedly
WHY it is impossible, and
HOW the mutation is blocked from happening and you have not answered. You have been shown that despite your claim of impossible, the genes are "changed" sometimes, and not simply "altered," and you ignore the news.
The evidence is found in
1) The existence of Ring Species which are transitioning from breeds to separate species. The farther apart the sub-populations are, the less successful cross-breeding is.
2) Hybridization. Mules and hinneys, ligers and tigons should not exist, but the separation of the parent species was never completed.
3) The human genome. We have completely mapped out the human genome and the chimpanzee genome. And we can see how close they are. They are as close as some of the species that can hybridize. We don't know whether or not we can hybridize with chimpanzees because it would be unethical to make the attempt.
This evidence establishes beyond doubt certain lines of descent. Alone, it is insufficient to establish Universal Common Descent, but when you add in other known genomes, such as dog and rat, and even more distantly similar organisms, and the fossil record it.
Sorry, but you keep making this typo and it just cracks me up.
