The End of Evolution By Means of Natural Selection

Hi Faith!Rest assured that everyone understands what you're proposing. It isn't complicated. Your scenario is not impossible, it could really happen, but it is an unlikely scenario among many with much higher probability, most of which include mutations, including beneficial ones. That's why everyone has been trying to help you understand the reality of beneficial mutations. See, for example, my so far unremarked upon Message 258.Finding beneficial mutations in higher organisms is extremely difficult. The larger the impact of a mutation the less likely it is to be beneficial, because the likelihood of a positive effect goes down the more widespread the changes. Beneficial mutations usually have a very tiny, indetectable impact, indetectable because higher organisms are the result of complex interactions between many different cell types. Finding beneficial mutations in humans shortly after they happen is especially difficult because not only are we complex, we have long generation times (coincidentally, just as long as the experimenters ) and experimentation on humans is frowned upon.Consider the elite athlete. For all we know some elite athletes may owe their abilities to beneficial mutations, but the kind of experimentation that might uncover such possibilities can't be done on people. But it has been done on other animals. For example, the whippet was found to have experienced a mutation that increased muscle mass and therefore speed (e.g., Why athletes should look to the whippet).Many genetic studies use bacteria because of their very short generation times, as short as 20 minutes in some cases. BlueJay provided a couple examples of beneficial mutations in E. coli in the other thread:

• Novel quinolone resistance mutations of the Escherichia coli DNA gyrase A protein: enzymatic analysis of the mutant proteins
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• gyrA and gyrB mutations in quinolone-resistant strains of Escherichia coli

The eventual product of DNA is proteins. A random genetic change can affect the resulting protein. In multicellular organisms that protein is released by the cell and travels throughout the rest of the body where it may or may not have a modified effect. Any modified effect could be deleterious or beneficial. It can be deleterious because at worst the protein's ability to function could be destroyed. And it could be beneficial because proteins are unlikely to be optimal, plus changing environmental conditions can turn previously satisfactory proteins into underperformers.--Percy

That would be a neat trick.--Percy

It's not a fantasy scenario, Faith. It's a thought experiment that addresses whether beneficial mutations are possible in principle. So let's try again.Allele TAG mutates into allele TCG which is mildly deleterious. Obviously the reverse mutation of TCG mutating back into TAG in a later generation is equally possible, so we can see that in principle there is nothing preventing mutation in a beneficial direction.Now we go a step further to consider the scenario where the TAG allele had never existed in the population but TCG did. There is again nothing preventing its mutating in a beneficial direction into TAG.So can we agree that in principle beneficial mutations are possible?--PercyEdited by Percy, : Grammar.Edited by Percy, : Grammar.

Before I comment on this I have to concur with Dr Adequate. Your unique, um, style makes it impossible to know what you're assuming and what you're not, or what you think is the context and what you think isn't. For this reason, when you're referring only to beneficial mutations you need to be explicit, because everyone here believes it is possible that at any moment you could change your mind and begin advocating anything else, regardless of what you've said previously.Evidence of mutations has been provided, so I presume you're not asking for evidence of mutations, but of beneficial mutations. Bacterial studies make clear that beneficial mutations are possible (we can provide this evidence again if that's necessary), so what you doubt is how well this applies to multicellular life. Do I have that right?--Percy

Hi RAZD,About ring species, call them A through E, Faith is arguing that both parent and daughter species can lose alleles. So if A has allele 1 and B doesn't, while B has allele 2 and A doesn't, that only means that A has lost allele 2 and B has lost allele 1. Since speciation is caused by allele reduction, if both subpopulations are losing alleles, but different ones, then speciation is only hastened. I don't think anyone has yet produced any evidence that would differentiate between Faith's view and ours concerning speciation in complex organisms like birds and lizards. I know you've been working hard at it, but length and detail isn't always effective rebuttal.I don't agree with Tanypteryx that Faith is a troll because I don't think she's doing this on purpose, but the effect is the same. Maybe I'm alone in this, but I see Faith's zaniness as more extreme this time around. For example, the refusals to consider evidence and valid arguments seem more blatant, and when she states that responses have only made her more certain that beneficial mutations play no role while never explaining any reasoning process that others could follow is especially crazy, as if she believes if she says something then it must be true, a sort of God complex.As others have argued in the past, many produce their best work when responding to Faith, and I do believe that board moderation and a more web-savvy membership is better up to the task this time around. I hope membership has a positive view of the way Smooth Operator's somewhat similar troll-like style was gradually limited to a single thread, because similar approaches will be taken going forward when deemed necessary.--PercyEdited by Percy, : Typo.

Hi RAZD!I don't think Faith is going to be able to follow the type of long structured arguments you favor.Faith rejects studies of simple and short-lived bacteria that falsify her position because she claims bacteria are too different from multicellular life to be relevant, and no one has yet produced any equivalent studies of multicellular life.What Faith doesn't have is a single example of reduced allele diversity producing speciation. Domestic breeding reduces allele diversity and never produces a new species, as creationists are fond in pointing out about cats and dogs. If reducing allele diversity was all it took to create a new species then breeders would have done it many times across human history, yet I don't think there's a single example.Faith can't explain why a parent population that has every allele of a reduced-allele daughter population never produces individuals that are not of the same species. If all it took to produce speciation was a certain mix of a subset of alleles, then just by chance large parent populations should be constantly producing individuals that are a different species. Speciation should happen all the time in just a single generation, but it never does.Faith's ideas are wrong in so many ways and on so many levels and even just at the level of simple biology that they should be overcome quickly and easily, but Faith's true genius is using her antagonistic temperament to avoid discussion.--Percy

One of the still open questions about dog evolution is whether its diversity springs from mutation after separation from wolves some 30,000 years ago, or from periodic breeding with the original wolf population.You don't want to get into a discussion about the definition of species. It's very messy. Suffice to say, and as Dr Adequate already alluded, species is an artificial categorization that humans impose upon a process of continuous change.--Percy

The scenario you describe, where both parent and daughter populations lose alleles through many generations such that the parent population comes to have alleles the daughter population does not have, and the daughter population comes to have alleles the parent population does not have, seems like it could produce speciation if it ever really happened.But the differences between the parent and daughter populations with regard to which alleles they possess is also heavily influenced by mutation. Whether you believe in beneficial mutations or not, every offspring has mutations that result in a unique allele or two (a reasonable average figure that's in the ballpark) not seen before in the species.Consider the population of rabbits in Australia (a population of millions and millions of rabbits). Each year millions and millions of baby rabbits are produced, and each one has on average one new allele. This means that each generation of rabbits gets millions and millions of new alleles. Given that reproduction is almost never perfect, this is inevitable. It isn't a case of whether it happens. It's a case of how you would ever stop it.--Percy

Since in this case the parent population possesses all alleles of the daughter population, every member of the daughter population can only possess alleles already in the parent population, just as is true for all members of the parent population. There's nothing genetically to distinguish a member of daughter population from the parent population.There isn't a single example in the technical literature of related species where one has a strict allele subset of the other. If reductions in genetic diversity were really a common way speciation happens and if mutations play little or no role then scientists should have long ago discovered tons and tons of examples of this, yet they never do. We're aware that in cases were there's no evidence you assume you're right. If you're into answering old posts, why not answer Message 309.--Percy

Yes, Faith, that's the point. Your view of evolution denies mutations and so requires that speciation happen in daughter populations that are genetically indistinguishable from any member of the parent population, since the daughter population has a strict subset of parent population alleles, just like all members of the parent population. Since on average each individual in a population receives one new allele through mutation, a daughter population having alleles unique to itself is pretty much guaranteed from day one. Yes, we know that when you're unaware of the evidence that you assume you're right. Hundreds of genetic studies of populations at varying levels of detail have been done so far, and none have even remotely hinted at the process you're proposing. One can't prove a negative, and so somewhere out there might be hiding the parent/daughter populations that support your view and we just haven't found them yet, but so far nothing.If speciation actually occurred only through loss of alleles then the evidence for this would be copiously obvious in the genetic data we already have in hand. For example, we'd find that short-lived species had many fewer alleles than long-lived species, since short-lived species will have gone through a series of many more speciation events than a long-lived one. We observe new mutations all the time. Bacterial studies in effect study mutations in real time. In more complex and longer-lived sexual species we can analyze the genomes of parents and offspring, and as the studies Bluejay mentioned reveal, each individual has on average around a hundred mutations that were possessed by neither parent, which averages to around one new allele per individual. Modern biology bemoans the demise of the naturalist. At one time biology was dominated by herds of roaming naturalists who dominated the landscape in their efforts to understand life, but while not extinct they have been largely replaced by biologists who take a genetic approach, yet despite the modern emphasis on genetics no hint of anything resembling your ideas has ever been revealed. Further, one would think that if your ideas had any merit that creationists like Michael Behe (professor of biology at Lehigh and author of Darwin's Black Box) would be advocates of ideas at least somewhat like yours, but they're not.--Percy

You've said this a number of times before, and the reason why positive mutations are so hard to detect has also been described a number of times before. If you're going to keep repeating this then at least in the interests of completeness, if nothing else, you might mention the explanation, or at least include a sideways acknowledgement that the explanation has been provided.--Percy

No, Faith, I was describing your scenario back to you. Let's go through a simple example.Assume a population with genes A through Z. Further assume that each gene has 4 alleles, 1 through 4. This means that we can give alleles names like B2 and X3.Now a daughter population breaks off. We can give this daughter population all the characteristics described in your scenario. First, it has only a subset of the parent populations genes. Let's say it has only the last two alleles of each gene. This means the parent population has alleles A1-A4, B1-B4, and so forth, while the daughter population has alleles A3-A4, B3-B4, and so forth.Let us further assume that when the daughter population breaks off that it takes with it all occurrences of some alleles, leaving the parent population bereft of these alleles. Let's say that that the daughter population takes with it all the alleles X3-X4, Y3-Y4 and Z3-Z4. So now for the X, Y and Z genes the parent population has only X1-X2, Y1-Y2 and Z1-Z2 alleles.Here's a complete list of all the alleles for each population:Parent population: A1-A4, B1-B4,..., X1-X2, Y1-Y2, Z1-Z2Daughter population: A3-A4, B3-B4,...Z3-Z4So your problem reduces to choosing a set of alleles from the daughter population for an individual such that it could never have been a member of the original parent population. This can't be done. Go ahead, play with allele combinations and convince yourself. It can't be done. If all the daughter population can do is play with a subset of the alleles from the original parent population, then it can never be anything other than a member of the same species as the original parent population.You can make this as dynamic as you like. Let us say that both parent and daughter populations fall on hard times and both decline in numbers until there is just a single individual in each, one a male and one a female. This is the most dramatic allele reduction you could imagine, since for each gene in each population there can be at most two alleles. But each individual only has alleles that existed in the original parent population. Individuals with precisely the same allele combinations as our two lone surviving individuals could easily have arisen in the original parent population and would have been recognized as members of that species. So obviously these two surviving individuals cannot be anything other than members of the same species as the original parent population.--Percy

You're asking the wrong question. It isn't a matter of whether it "occurs in reality." It's a matter of what could ever stop it from occurring.Let's look at it from a slightly different angle. Can we agree that it is possible for none of the alleles of a gene to be optimal? In other words, can we agree that is possible that a tiny change (i.e., a point mutation, an error in a single nucleotide) to one of the alleles for a gene would transform it into an allele that is superior to any of the existing alleles?If we can agree on that, then what would prevent such a change from occurring? Nothing, right?Now, taking the human race as an example, realize that each individual has one new allele on average, and that around 134 million babies are born each year. Each baby contributes one new allele to the world population. Current estimates give us around 20,000 protein-coding genes, so that's 134 million new alleles for 20,000 genes, or around 6700 new alleles per gene, on average. Every year. Year after year. Endlessly.Unless all genes contain optimal alleles, beneficial mutations are inevitable.--Percy

Hi Faith,Over at the Reduction of Alleles by Natural Selection (Faith and ZenMonkey Only) thread in Message 76 you said: Since in your view the flood was real and four thousand years ago most species were reduced to only one pair of individuals, how can you characterize ZenMonkey's scenario as hypothetical? Since the only place for an allele to be stored is in a gene, and since in sexual species each gene in an individual can contain at most only two alleles, and since you believe mutations are not a factor, how could most species today have more than four alleles for any gene? Where are you putting these "built-in" alleles if not in the gene they belong to?--Percy

An allele can be recessive to all other alleles, but not to itself. As soon as it is paired up with itself it can be expressed.--Percy