More Evidence of Evolution - Geomyidae and Geomydoecus

It's not proof at all, even for Darwinists. It's only additional evidence for a theory already in possession of a wealth of evidence. What distinguishes this evidence from much other evidence is the clarity of support it provides for co-evolution. I think we were already well aware of your opinion, but this doesn't address the topic of this thread. The paper describes research identifying a number of cospeciation events between gophers and their resident lice. This means that the gophers and lice often experienced speciation events at roughly the same time, according to the paper with a probability of less than 1% that it was due to chance.Why don't you take a look at the paper, it's pretty straightforward: --Percy

I can't be sure what you're actually saying, so let me just explain a little about random mutation and natural selection.Mutations are largely random. Where and when they occur and what affect they'll have on the organism can't be predicted. Some types of mutations are more likely than others, and some DNA locations are more likely to experience mutations than others, but to a first approximation mutations can be considered random.In a population of organisms such as lice, natural selection decides which lice survive to reproduce and which do not. Natural selection is not a random process. The "natural" part of natural selection refers to the natural environment. A random mutation makes the organism either better able to compete in the environment, or it makes it less able, or it has no effect either way. It is the natural environment imposing its will upon the organism that allows it either to survive and reproduce or to die and have its genes die with it. This is selection in the wild, which is natural (as opposed to breeding), hence the term natural selection.Random mutation is one of the engines of variability (allele remixing is another) upon which natural selection operates. The mutations create a wide range of characteristics among a population of organisms, and natural selection decides which ones have offspring that comprise the next generation.--Percy

The explanations offered by others are correct. In the sentence you quoted, the "chance alone" portion refers to the statistical probability that their findings are due to chance. It doesn't refer to mutations or to natural selection. Mutations are, to a first approximation, random. Natural selection is non-random because it is imposed by the environment in which the organism resides.Discussions about creation/evolution often focus on the evidence for evolution, and Crashfrog highlighted this particular paper because he believed the evidence it offered was particularly compelling. Evolution predicts that changing environments create pressures upon organism by making their lives more challenging. A changing environment destroys the stable relationships organisms have with their environment and with other species. Any random mutations that happen to provide an advantage in the new environment will be seized upon and rewarded by natural selection by allowing those organisms to produce more offspring more often.This particular research is significant because the DNA histories (phylogenies) of mole and lice have changed in concert. When mole DNA experienced a significant event, so did lice DNA. This would be very unlikely if selection of random mutations were itself random. It strongly suggests (P < .01) that whenever the mole changed, the lice changed, and vice versa, in a cause and effect manner. The mole provides the environment for the lice, and any changes in mole morphology (shape and structure) were accompanied by changes in lice morphology. In the aggregate lice populations also had their effects on moles and provided pressure for change upon mole populations.But not only is this evidence for evolution, since it is precisely what evolution would predict, it is also evidence against both design and divine creation. No designer or god would include in DNA the signposts of evolutionary changes that never actually happened.--Percy

I'm not sure that you could be accurately characterized as the epitome of meekness. You're pretty aggressive for someone who still misunderstands the P<.01 part, and it's causing you to misinterpret all the rest: The P<.01, which is where I presume your 100:1 ratio comes from, applies to the statistical possibility that the findings of the researchers were due to chance. It does not apply to the possibility that a mutation will be selected. The paper doesn't mention such things, doesn't even speculate about them. The word "mutation" doesn't even appear in the paper.Let's say I was doing a study on a cancer treatment, and I discovered that the treatment on average reduced mortality in the year following initial diagnosis with a P<.01 probability of being due to chance. That doesn't mean the cancer patients had a 100:1 chance of survival. The P<.01 doesn't apply to the cancer patients at all. It applies to the probability that the study's results are due to chance. In other words, it's the probability that the study's results are incorrect.Anyway, I again suggest you read the paper: But let's examine part of your concluding comments: This observation is incorrect for two reasons. First, as already explained, the P<.01 is not the probability of a random mutation being selected by natural selection. It's the probability of the statistical results of the study being due to chance.Second, and more importantly, calculating the probability that a random mutation would be selected would be meaningless for the type of information this study was focused on, and nothing in the study would enable you to reach conclusions of this nature. But I understand the conclusion you're trying to reach, and it's clear you're thinking about the interplay of mutation and natural selection in the wrong way.Mutations occur all the time, but mutations in any species that is already well adapted for it's environment are likely to be selected against by natural selection. For example, if a rabbit is already well adapted for an annual average temperature of 60^oF, then any mutation that makes it better adapted for 55^oF or 65^oF would be selected against. It is only when the environment changes that mutations affecting temperature adaptation can be selected for and become fixed in the population so that a later generation of scientists can discover it in the DNA.This is why I mentioned that the mole forms the environment for the lice, and changes in mole morphology represent a change in lice environment. This places environmental pressure upon the lice, and now the constantly occurring mutations have a better chance of making the lice better instead of worse adapted, and so have a better chance of being selected instead of rejected. And so the mole and the lice speciate in concert with one another, and the evidence for these speciation events is recorded in their DNA, which is what the scientists who wrote this paper studied.Interestingly, your own idea of directed evolution is also consistent with this evidence (indeed, it would be consistent with any evidence, which is one of its problems), but speciation is taking place today, both artificially in the lab and naturally in the wild, and no designer/builder has even been detected tinkering with either mutation or selection.--Percy

A beneficent designer would of course evolve his creations as necessary. The limited mobility of this type of lice made it necessary for the designer to evolve the lice whenever he evolved the moles.Being consistent with the evidence isn't an argument in favor of directed evolution. This is the problem with all proposals of godlike designer/builders, where whatever the evidence shows happened, that's what the designer/builder did, so they're not testable. Even worse, there's no positive evidence for any designer/builder.--Percy

I'm actually replying to both Chiroptera and Crashfrog, not just Crashfrog.I think Hoot Mon raises a good point. A good sized segment of those on the science side believes the issue is one of education, that if only people were more informed they'd be more accepting of evolution. For those of us who accept this perspective (one I'm growing less and less receptive to), Hoot Mon is arguing that we're not doing as good a job as we could of educating MartinV.But the larger issue that this brings to mind is that the education approach is not an easy one. All creationist miseducators have to do is portray their fallacies in any number of convenient and easily understood ways and the evolutionists have a multi-day re-education task on their hands, one that most creationists won't stick around for, or that discussion won't stay civil long enough for.Attempting the educational approach is worthwhile because at a minimum it makes clear to those newly arrived at the issue that there are sound evidence-based reasons for accepting evolution. But while there will be conversions in both directions, the vast majority of people who care are already entrenched in their positions, evolutionists because of evidence from the natural world, fundamentalists because of revelation from God in the Bible.So when fundamentalists attempt to influence boards of education to select certain textbooks or change the science curriculum, while attempts to educate such boards is still a good idea, there are other options more likely to have a positive effect. These options do not address the hope of reconciliation between the two sides, but they do allow science education to kept free of religious influences. Such approaches tend to ignore the specific scientific issues and stress public relations approaches that characterize the fundamentalists as special interest groups, emphasize the economic risks to a region perceived as anti-science, and highlight the negative effect on the opportunities for higher education for students from such regions applying to universities.--Percy

I actually thought Hoot Mon's example was okay. Exaptation happens when a feature becomes used for a purpose other than the one for which it evolved. In Hoot Mon's example the hitchhiker's thumb did not play a role in sexual selection, and then it did. It didn't evolve for the purpose of sexual selection, so this *is* an example of exaptation. His example has to be somewhat qualified since something else evolved (sexual selection) to change the hitchhiker's thumb's purpose, which is why it isn't a perfect example.But even if I'm wrong and Hoot Mon's example is full of holes, the point he was trying to make still holds, that a mutation might already be expressed before something else changes to make it vulnerable to selection pressures.But even though Hoot Mon's point is valid, it's a minor quibble of a point. Chiroptera was only trying to explain a principle in a general sort of way, not enumerate all the possible circumstances and permutations.--Percy

Martin, if you're getting the "1:100" number from the "P<.01" in the paper, then it doesn't apply the to probability of mutations being selected. The paper doesn't address mutation selection probability in any way. The word "mutation" doesn't even appear in the paper. The "P<.01" refers to the probability that the study's result is valid.If you're getting the "1:100" number from somewhere else, then please explain where you're getting it from.I have to concur with Chiroptera. Your misunderstanding combined with the language barrier makes it difficult to tell your post from nonsense.--Percy

I don't get it either. Hoot Mon began by suggesting that we weren't giving MartinV a sufficiently complete explanation, but his own suggestion seemed to wander off into minor quibbles that I didn't think were all that bad as far as accuracy, but I didn't see how they would be helpful to MartinV. It seemed like piling some fairly subtle detail onto someone who's already having trouble just understanding simple English.--Percy

Natural selection can only allow an entire individual to either survive to reproduce, or not. There is no method by which natural selection can select only some of the traits of an individual to pass on to its progeny. I can only assume you're thinking of populations, but it was clear that Crash was referring to individuals. In trying to keep things understandable for MartinV, something you've emphasized yourself, Crash focused on selection at the level of the individual. I suppose one could quibble about whether the point would be more clear to MartinV if made about populations rather than individuals, but this thread is already having trouble staying on topic. Now I'm beginning to wonder if you're just using MartinV as an excuse to quibble about anything you feel like. English is a second language for MartinV, he's already having trouble with simple distinctions, so it seems a foregone conclusion that drawing fine distinctions between convergence and parallelism would only be inviting further confusion. I think that for a start we should help MartinV understand what P<.01 refers to. Focusing on this would be constructive, *and* it has the added bonus that it actually concerns the paper mentioned in the opening post! --Percy

For reasons known only to himself, Hoot Mon is raising off-topic objections. This would seem to indicate that he doesn't have a basis for objecting, but he doesn't like the paper's conclusions, so he's objecting anyway with whatever comes to mind. Plus I'm wondering if there's a history between you two, because the animosity seems a little strong for a first or second encounter. Anyway, the problem with these off-topic objections is that they invite reply because they're either wrong or misleading.Perhaps it would work just to answer that if he'd like to discuss these other topics that he should propose a new thread, then drop it.--Percy