The End of Evolution By Means of Natural Selection

A specialized dog breed where some members breed with the general dog population will tend to lose its unique character and revert, just as you say. But if it maintains its isolation it will still pick up new mutations which will cause it to not only lose its unique character but also become more and more different from the general dog population, which is how speciation eventually happens.As Dr A has explained, any dog breed is still a dog. It possesses a unique subset of dog alleles, and mixing and remixing that allele subset has only limited means of changing the breed to a new species (I know dog breeders want to maintain the breed, but remember that your true focus is on how new species are created, not how they're maintained). Mutations, which are brand new alleles completely unique to dogs, have the potential to change the breed much faster than allele remixing. Mutations are a common component in speciation.By the way, mutations do make contributions to breeding. For example, the dachshund's short legs originated through mutation (Scientists discover secret of why dachshunds have short legs).--Percy

Hi Faith,Take all the time away you need. In the meantime I'm going to attempt to describe why a unique species cannot form from an allele subset.Assume a population has 26 genes labeled a-z.Further assume that each gene has 4 alleles labeled a₁-a₄, b₁-b₄, and so forth.An earthquake occurs that causes a river to change course, and a subpopulation becomes trapped on land that is now an island. This population only has the first two alleles of each gene, a₁-a₂, b₁-b₂, and so forth.If this alone were sufficient for speciation, then you should be able to list a combination of specific alleles that could form in the subpopulation but not in the main population. How are you going to do that, given that every allele in the subpopulation exists in the main population? For example, try this one: There's not a single allele in that list that doesn't exist in the main population. No matter how you mix and match alleles in this subpopulation, it is impossible to come up with a combination that couldn't happen in the main population.That's why allele reduction does not result in speciation.--Percy

I assume Faith will be focusing her energies on the new Reduction of Alleles by Natural Selection (Faith and ZenMonkey Only) thread, so we can use this thread for commentary. This is from Message 3 in the new thread: So when Faith wants to add new features to her computer, she deinstalls some software and voil! New features emerge. --Percy

I suggest you focus your energy on the other thread.--Percy

There's nothing that obligates you to confine your participation to the other thread, but the whole purpose of that other thread was to reduce your workload so you can respond to just a single individual and not get so frustrated that you post single word messages like "ptui."--Percy

I again suggest you focus your energies on the Reduction of Alleles by Natural Selection (Faith and ZenMonkey Only) thread.--Percy

Of course there's no rush, but Reduction of Alleles by Natural Selection (Faith and ZenMonkey Only) was created so you could have a one-on-one, instead of the many on one you have here that was causing your meltdowns. If you're going to put your energies into this thread instead of that one then I hope we see no more meltdowns and complaints about how unfair it is that you're outnumbered, because we set up that other thread for the explicit purpose of helping you avoid these problems.Some people you just can't help.--Percy

I again and most earnestly encourage you to focus your efforts on the Reduction of Alleles by Natural Selection (Faith and ZenMonkey Only) thread.--Percy

Hi Faith,I notice that many of your messages have a ton of edits just after you post them. If you examine the message entry page you'll see several buttons below the message box. One of them is "Preview". If you click on the "Preview" button you'll see precisely how your message will look when it is posted. Unlike much other discussion board software, dBoard uses the exact same code to render previews as it does the messages in the threads. There won't be any differences. If you use "Preview" you'll save yourself a lot of edits, plus dBCode errors are displayed in red, making them easy to find and fix.--Percy

I disagree about how Faith is wrong. She's just repeating the same thing she's said many times, that the daughter population has the same genes as the main population, but that only a subset of the main population's alleles populate those genes. She's still denying the other possibilities, such as that new alleles and even new genes can be created.Faith somehow is failing to grasp the significance of the evidence you presented, I'm not sure why, but hopefully if we continue focusing on it the point will eventually get across. Clearly Faith passionately believes that beneficial mutations are impossible, and I guess this allows her to ignore your evidence that there is no progression of diminishing alleles as one traverses around a ring species, in any direction.--PercyEdited by Percy, : Change author.

The article you cited, The greenish warbler ring species, describes the phenotypic differences but is non-specific about the genetic differences. There is no data contradicting Faith's belief that the differences are due to allele reduction.--Percy

No, he meant genes. For example, consider two adjacent species in a ring, call them A and B. RAZD believes that A has genes B doesn't have, and B has genes A doesn't have. This would be impossible if your views about allele reduction being the only cause of speciation were correct. RAZD hasn't presented the underlying evidence yet, so stay tuned. I don't understand what you're trying to say. In many posts you have argued there are only deleterious mutations, but now you're claiming there are no mutations at all? Please clarify.--PercyEdited by Percy, : No reason given.

Hi RAZD,You're using knowledge that Faith does not accept to reach conclusions about the distribution of alleles in a ring species. You need evidence of two adjacent species A and B where A has an allele B doesn't and B has an allele A doesn't.--Percy

There's no misunderstanding, Faith. ZenMonkey described your own views back to you in detail to make clear that's there's no misunderstanding on our part. He did it because you mistakenly believe we reject your views because we don't understand them. That's wrong. We understand your views and reject them because they do not describe what actually happens in the real world.--Percy

Imagine a very simple gene whose alleles are all just a single codon. One of those alleles is TAG. This allele experiences a mutation during reproduction and becomes TCG in the offspring. It turns out to be mildly deleterious. The offspring survives and reproduces but does not thrive, meaning it contributes fewer offspring to the next generation than is average for its species.A few generations later one of its descendants experiences a mutation in the same allele in the same gene and the TCG allele by chance becomes once again TAG. If the previous mutational change from TAG to TCG was mildly deleterious, this reverse mutational change from TCG back to TAG has to be mildly beneficial.So now that you see that beneficial mutations *can* happen, let's take it a step further. Assume this gene has never had the TAG allele. It's had the TCG allele and some others, but never the TAG allele. There's nothing to prevent a mutation in the TCG allele from transforming it into the TAG allele, which is a beneficial mutation.You see, Faith, beneficial mutations are possible.--Percy