Random mutations shot down on this site.

Does this mean that you have some sort of point relevant to the OP which you just entirely failed to bring up or did you just want to bring in some random stuff about your own different strawman to confuse the issue?TTFN,WK

Wow, that places me in some pretty esteemed, august company. Thanks, HM!Nonetheless, I wasn't aware that pointing out that a statement like "wild digital codes circulate through our homologies" was essentially nonsense - like a kind of biological I Ching - constituted being obtuse. In the circles I run with, it's considered being "truthful", or "clear", or "not being a jackass who thinks his made-up bullshit counts as science."For instance: Only someone completely ignorant of the issue would assert that differential reproductive success is something somehow different or additional to natural selection. It is selection, as is differential mating. That's why there is selection - reproductive outcomes vary among individuals. (They're different, in other words, since you seem to have some trouble with terminology.)You open your mouth on these issues, HM, and you reveal the fact that you have no idea what you're talking about. What I can't understand is why you don't think we'd notice that you're flying by the seat of your pants, here. Do you think none of us have any expertise in the biological sciences? That we're a bunch of country bumpkins you can baffle with yer fancy science-soundin' werds, like "endosymbionic"?And, of course, when this is pointed out, we get a steady stream of playground invective. A pretty predictable plan B - when your bullshit fails to baffle, discredit everybody who's seen through you. By... selection, maybe? Kind of undercuts your whole thesis, doesn't it?

First of all, I don't see it as an insult to be placed together with the 2 greats like DC and froggie. But more to the point, how is pointing out a strawman that is not quite obvious to the gullible obtuse?

Hi Hoot. You seem to be confusing a bunch of different concepts here, to the point your whole argument becomes a mish-mosh of unrelated terms, synonymous terms, or terms that are actually elements of other terms. For instance, in talking about different causal factors in speciation you state: 1. Genetic drift has only theoretically been shown to cause speciation. In other words, it is possible but no actual unambiguous cases of speciation by drift have been demonstrated. It is believed that drift may be a key factor in founder effect speciation due to the obviously small population (the possibility that rare alleles come to fixation randomly - or disappear randomly due to stochastic rather than deterministic (selection) effects). The idea is a peak shift that produces reproductive isolation from the original population. The real problem is that it is practically impossible to ascertain the relative role of selection and drift in any given speciation event. WK may have more up-to-date info.2. Gene flow has nothing whatsoever to do with speciation, except in the sense that restriction on gene flow between two populations (allopatric speciation) is an indicator that speciation may occur if the populations are separated long enough and are in environments where differential selection pressures require a change in the adaptive landscape of the two. However, gene flow ITSELF does not cause speciation.3. Differential mating (do you mean assortative mating?) is simply an odd way of saying sexual selection. Sexual selection is a special case of natural selection, not something different. Unlike drift, however, there does appear to be a good case for sexual selection leading to speciation (e.g., tree frog calls, etc., and species richness in certain groups - for a good general discussion, see Futuyma, Evolutionary Biology, Sinauer 1998 pg 490-91).4. Differential reproductive success is the result of natural selection. It's not something special that leads to speciation.See what I mean? You might want to go back to the books before you post more of what amounts to nonsense.

You are quite wrong. I don’t understand how you can say that. Are you keeping up with the literature? Daniel Hartl, a leader in this field, certainly would disagree. In his Essential Genetics/A Genomics Perspective (2002, coauthored with Elizabeth Jones), Chapter 14”Population Genetic and Evolution”is rich with experimental evidence of drift. He and others have built predictive models of drift that show striking accuracy under experimental conditions. Random genetic drift, of course, is not a selective process. OK, to the books. Let’s review the five potential causes of microevolution:1. Natural selection, or otherwise described as differential success in reproduction.2. Random genetic drift, either founder or bottleneck, that can occur when a population’s size drops below some crital level. This is NOT a selective process.3. Gene flow, which amounts to losses or gains of alleles in a population, associated with the movement of individuals or gametes. This is NOT a selective process.4. Mutation, random changes in an organism’s DNA that results in new alleles. This is NOT a selective process.5. Non-random mating, which means that the males mate disproportionately with certain females within a population (The Hardy-Weinberg equilibrium requires all males and females of a population to have equal reproductive access to one another). This is NOT a selective process. Even though some males or some females might themselves be selective in their mating, this is not the same thing as “natural selection.”Any questions? Otherwise, it's time for you to head on down to the library.”Hoot Mon

Such tripe! I was responding to the opening post by DidDug Master: I wanted him to know that mutation and selection are not the only potential causes of microevolution. Please see Message 20 for more. So get outta here with your strawman confusion?”Hoot Mon

You're lame, crashfrog. There is no significant difference between that and a buck snort. I think you watch too many soap operas in the afternoon.I'll refer you to Message 20 to help further your education. As The World Turns...”Hoot Mon

You mean, where you clearly didn't understand what Quetzal was talking about, and then told a research biologist with years of experience in his field that he needed to hit the books?Yeah, I can see how that would really help me out. Quetzal can defend his own posts, of course; but judging from your response I think we've figured out why you don't know the first thing about what you're talking about - you're having some trouble reading statements in plain english.

It seems there is more nastiness than debate here now. I'll open it again when everyone has a chance to cool down.I might note though, Hoot Mon, that you did in fact post the words quoted, that they are, as best as I know, nonsense in this context and you have never actually explained them to point out how they are not nonsense.If you wish to defend what you post fine but you will have to avoid attacking those who, legitimately, attach the words you use or concepts you put forward.If you do not wish to defend your words (even from nit pickers) then don't post them.

You are again confusing a few things here. YOU specifically stated that genetic drift was an alternative to natural selection as a cause of speciation. I pointed out that there have been no unambiguous examples of speciation due to drift. How you got from that to me denying drift occurs (which is what your chapter is apparently talking about, btw, if I understand what you wrote) is beyond me. There is LOTS of evidence of drift in small populations (where stochastic effects are much more significant than selective effects). You evidently misunderstood me. In the future, if you have any question about something I wrote or need clarification I'll be happy to provide it. Number one is of course uncontroversial. However, as I pointed out above, number 2 is NOT a cause of adaptation. In fact, drift can cause a population to become maladaptive (move off the adaptive peak of the parent population). In addition, it is not required that the population subject to drift be either a founder or suffer other types of bottleneck. Obviously drift operates more noticeably in small, isolated populations, but random frequency shifts due to drift occur in all populations (or at least that's the theory). I'd be curious as to where you got this definition of gene flow. Gene flow is simply a quantitative representation of the degree of genetic exchange between two populations. It doesn't say anything at all about gain or loss of alleles. A restricted gene flow between two populations just means that there is more chance that the usual factors of random mutation and differential selection pressures can eventually result in reproductive isolation arising between them. Other than that, gene flow has sod all to do with speciation. True, as far as it goes. However, for those new alleles to become fixed in the population (not individual organisms - another mis-statement), selection MUST drive the frequency change. The only exception - and a theoretical one at that - is the case where drift operating on a small population randomly causes the novel allele (especially if neutral or even mildly deleterious in the particular environment) to rise to fixation. What are you talking about? Hardy-Weinberg equilibrium doesn't even WORK in the presence of non-random mating! It's one of the key assumptions of the equations (along with infinite population size, etc)! Sexual selection IS a sub-set of natural selection, in that it represents a natural feed-back loop which reinforces mate choice and hence reproductive success by selecting certain traits to emphasize. LOL. Thanks, you just made my day.

Hi crash,Just as a point of clarification (not that it matters), I'm not a "research biologist". In fact, I haven't been in a lab since I got out of school (except as a visitor). For reference, I'm a tropical ecologist who specializes in: endangered species conservation; protected area design and management (local, national, regional); landscape restoration (reforestation, riparian corridor design/construction, and watershed conservation); and rehabilitation and reintegration of locally extinct or endangered species (mostly working with amphibs and small primates) to include closed-cycle production-and-release. Additionally, because of the protected area work, I've developed a pretty strong expertise in small-scale integrated farming, community agroforestry systems, and sustainable development (especially ecotourism). In other words, if you want to know the nutritional and habitat requirements of Paleosuchus trigonata, how to design and plant a biocorridor, how to develop and implement an effective invasive species program, how to transition a formerly domesticated Lagothrix lagotricha to the wild (it's a generational thing), or why that particular Shuar indigenous community shouldn't attempt an ecotourism project as a development scheme (among many other things), then I'm your man. It doesn't require a biologist to see that Hoot is off-base. Of course, I do have a few years experience .

I apologize for being ham-handed in my attempt to defend you. It wasn't my intent to misrepresent your background, of course; I simply chose a term I had hoped would be sufficiently broad as to have a good chance of encompassing what you actually did (which I couldn't remember, but I was pretty sure you weren't a classroom lecturer.)Clearly I guessed wrong. But I thank you for the correction and I appreciate the information. What you do sounds quite fascinating, in fact.

I understand and will comply. In this regard, then, I am posting here what I posted as message 75 on the "Origins of New Allelles" thread: I notice that you and a few others here are very keen on your what you perceive to be the correct usage of terms that pertain to genetics and biological evolution. You in particular, crashfrog, are “correct” to the extreme, or otherwise pedantic about common editing mistakes. Once, upthread (message 35), I meant to write “endosymbiotic” but wrote “endosymbionic” instead, and you have pestered me over this typo on several different threads now (for just a single-letter slipup!). On another occasion (message 33), you flailed at me for using the term “mariner genes” when I meant to say “mariner elements,” which geneticists often associate with “jumping genes.” These are simple cases of typos and misspellings. How would you like it if I scanned over your posts and found misspellings and typos to make a big fuss over? You’re grasping at triviality and it doesn't help your case.Then there is this matter of “digital codes circulating through our veins and homologies” (message 66), which you claim to be nonsense. Others have joined you in this claim; even AdminNosy got involved and closed a thread over it. But I’m here to tell you (et al.) that my comment about “digital codes circulating through our veins and homologies” is NOT nonsense. Maybe it offends your youthful orthodoxies somehow, but this tells me you haven’t read enough literature on the subjects of genetics and evolutionary biology to lighten up a little (this forum is NOT a refereed journal, you know). S. J. Gould is one who used the terms “homology” and “homolgies” to refer to lineages of inheritance”applicable to discussions about “homoplasy” and “convergence,” which are alternative explanations for microevolution.Furthermore, genes ARE digital codes, according to Richard Dawkins. We’re talking here about the movement in space and time of digital codes”those mobile alleles”which do indeed circulate in our bloodstreams and through your homologies.I am sincere about discussing all aspects of allelic movement and their athletic leaps across space and time. And I’m sure I’ll hear demands from you for proof that alleles are “athletic.” You will probably scream bloody murder. But I wonder if any of Archie Manning’s athletic alleles ever found their way into Peyton and Eli. If so, that might have something to do with Archie’s digital codes, circulating through his veins and homologies.Now let’s get on with this discussion about alleles and their origins.”Hoot Mon

First off, I am sorry for any insults I flung your way. That was rude and unnecessary.Now, we seem to have gotten disconnected on “speciation” vs. “adaptation.” I see adaptations as relevant to natural selection, but not relevant to drift or other non-selective means of microevolution. Please correct me if I am wrong.Now, on the issue of speciation and the role of drift, I wrote in Message 15:

quote:

---

Two British evolutionary biologists, Nick Smith & Adam Eyre-Walker (Adaptive protein evolution in Drosophila, Nature, 2002) have studied adaptive protein evolution in two fruit-fly species, D. melanogaster and D. yakuba. They determined that the two species separated about 6 million years ago, and that 45% of the separation could be attributed to natural selection. The remaining 55% of the protein differences were determined to be selection-neutral, and these difference were attributed to genetic drift.

---

They are taling about speciation here. I don’t know why you want to impose “adaptation” on a non-selective microevolutionary agency. Again, I’m open to correction here. It’s common in college textbooks. For example, Campbell et al. in Biology/Concepts and Connnections (2000, p. 271) describe gene flow this way:

quote:

---

The second agent of microevolution, gene flow, is the gain or loss of alleles from a population by the movement of individuals or gametes.

---

I don’t understand this. But if you are saying that microevolution occurs in populations and not in individuals, then I certainly do agree. I wish I could get you to examine Smith and Eyre-Walker’s Science article, reference above. They found 55% of the protein differences between two fruit fly species to be attributable to drift. And please see the work of Daniel Hartl, also referenced above. He often stresses the non-adaptive aspects of speciation. But, Quetzal, that’s just what I said:

quote:

---

(The Hardy-Weinberg equilibrium requires all males and females of a population to have equal reproductive access to one another)

---

”Hoot

The full text of the article is only available to subscribers, and the abstract doesn't even mention genetic drift. Could you provide relevant excerpts from the article that support your point? Right. We understand the point you're making, we're just trying to determine if the article actually supports your point. Genetic drift by its very nature would seem an odd candidate for the cause of much speciation.--Percy