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Author | Topic: What is the mechanism that prevents microevolution to become macroevolution? | |||||||||||||||||||||||||||
Faith  Suspended Member (Idle past 1471 days) Posts: 35298 From: Nevada, USA Joined: |
I've read that kind of stuff already, That article you linked . No way those estimates of tens of thousands of years can mean anything to me; just a fantasy of theirs based on a different set of expectations. Obviously they can see *something* there, but their numbers are no doubt skewed by their denial of the first great "bottleneck," the starting of all human beings from Adam and Eve, as well as the second at the Flood.*
You too of course have a different set of ideas about the history of DNA on which to calculate how much diversity you would expect to see. No, you are wrong, I'm not saying diversity shouldn't be there. You are. I've many times acknowledged that there is still a lot of diversity left. Yes, the mere fact of death itself would over time kill off a lot of genetic material. But we only have 1% functioning DNA left. That suggests to me that the great flood bottleneck is probably reflected there.
* They are addressing "anatomical and archaeological" evidence for this supposed bottleneck. I wanted a GENETIC indicator of a bottleneck since others here, jar anyway, claim it's so OBVIOUS. The article says that "Such an event would be expected to leave a significant mark across numerous genetic loci and observable anatomical traits" -- well, what SORT of "mark?" What's wrong with all taht junk DNA as such a "mark?" I mean billions of human beings died in that event; it should have left a pretty dramatic "mark." Edited by Faith, : No reason given. Edited by Faith, : No reason given. Edited by Faith, : No reason given.
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Faith  Suspended Member (Idle past 1471 days) Posts: 35298 From: Nevada, USA Joined: |
Oo, this is interesting from that article you linked :
There are many reasons to believe that there may have been a number of severe population size bottlenecks on the lineage leading to living humans, principally because of the many speciation events that must have occurred. Yes, of course. THAT'S WHAT SPECIATION DOES, IT SEVERELY REDUCES GENETIC DIVERSITY. That's what a bottleneck is, severely reduced genetic diversity. Edited by Faith, : to add link
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anglagard Member (Idle past 863 days) Posts: 2339 From: Socorro, New Mexico USA Joined: |
Faith shouts:
Yes, of course. THAT'S WHAT SPECIATION DOES, IT SEVERELY REDUCES GENETIC DIVERSITY. So the act of speciation, which creates more species, means less genetic diversity. Then according to such logic, an infinite amount of species would have the least genetic diversity, while one species would have the most genetic diversity. Does that also mean that an infinite amount of numbers would have the least numerical diversity, while one number has the most numerical diversity? Guess up is down when you can't tell the difference.
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mjfloresta Member (Idle past 6020 days) Posts: 277 From: N.Y. Joined: |
Faith shouts: Yes, of course. THAT'S WHAT SPECIATION DOES, IT SEVERELY REDUCES GENETIC DIVERSITY. So the act of speciation, which creates more species, means less genetic diversity. Then according to such logic, an infinite amount of species would have the least genetic diversity, while one species would have the most genetic diversity. Does that also mean that an infinite amount of numbers would have the least numerical diversity, while one number has the most numerical diversity? You ask if speciation means less genetic diversity. I have two answers, not necessarily and probably. You have to keep the proper frame of reference. We start with a specific amount of genetic material within a population; As the population speciates, the genetic information gets divided up amongst the various isolated populations. Of course there's a lot of redundancy; that's why speciation is normally a slow process. Let's suppose we have a species that possesses 30,000 genes. Two populations form from this species that become geographically isolated. Originally, there's a lot of genetic redundancy (or overlap). So let's suppose that of the original 30,000 genes, all the alleles are present for 29,990 genes. But for a small number of genes (10 in this case) there is geographic isolation, no overlap between populations. This occurs purely by chance, remember. So, is there a reduction of genetic diversity? Not really, the sum population still possesses the full diversity of alleles among its 30,000 genes. However there has been a reduction of genetic diversity as seen in each population. Now, time adds up; This process repeats itself, until specific alleles become so poorly represented in a suficiently small population that they are in danger of being lost, should that population cease to be. In fact this is what happens, resulting in a true loss of geneticdiversity, both from the over-arching population view and as seen on the small population or individual level.. An infinte amount of species (as you brought up) would not necessarily be equated with a loss of diversity, but it likely would because of the afore-mentioned factors..
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Wounded King Member Posts: 4149 From: Cincinnati, Ohio, USA Joined: |
hey are addressing "anatomical and archaeological" evidence for this supposed bottleneck. I wanted a GENETIC indicator of a bottleneck since others here, jar anyway, claim it's so OBVIOUS. Wow! Did you even read the whole abstract? They cover 'microsatellites, Alu insertions, and single-nucleotide polymorphisms (SNPs), as well as single genetic loci, including -globin, dystrophin, and ZFX', and that is only the autosomal elements. They also refer to analyses of mitochondrial DNA and the Y chromosme.
well, what SORT of "mark?" What's wrong with all taht junk DNA as such a "mark?" I mean billions of human beings died in that event; it should have left a pretty dramatic "mark." Fer Cryin' out loud. Not a mark like a stamp on the DNA saying 'I honk for bottlenecks'. The mark is the particular patterns of genetic deiversity across different genes which suggest they originated within a population of a particular size. There is no way that anything in Junk DNA can lessen the diversity at other genetic loci, and subsequently no way that it can represent any sort of mark outside of whatever contribution comparisons of 'junk' elements such as in the case microsatellite regions themselves make to the estimates of ancient population size. You have to realise Faith that your Supergenomes that you posit are nothing but make believe. There isn't a scrap of evidence that they ever existed and the whole concept of them makesany analysis of genetic bottlenecking completely irrelevant. If we allow a very few individuals to carry the genetic diversity we would expect in a population size of thousands then our genetic analyses are next to meaningless. Which should be no surprise, when you start making up magical genetics ad hoc it is always likely to lead to conflict with the actual genetics that we see in operation all around us. TTFN, WK Edited by Wounded King, : No reason given.
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anglagard Member (Idle past 863 days) Posts: 2339 From: Socorro, New Mexico USA Joined: |
You ask if speciation means less genetic diversity. I have two answers, not necessarily and probably. You have to keep the proper frame of reference. The proper frame of reference is called common sense instead of irrational fanaticism. Your model assumes no mutation can ever exist, "good," "bad," or otherwise. The argument boils down to stating the subset of genes in one species is greater than the set of all genes of all species, which is obvously false by definition. Additionally, if humans and chimps share 98% of the genetic code, where did the other 2% come from? Bacterial devolution? Degeneration from the fall? Subsets being greater than sets? Please consider the role of common sense when making assertions.
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mjfloresta Member (Idle past 6020 days) Posts: 277 From: N.Y. Joined: |
What does "common sense" have to do with anything? To you common sense is clearly something different than to me.
I gave you the explanation of speciation that almost every biologist would agree with. How that beomes "irrational fanaticism" i'm not too sure. But tell me more about this "common sense" criteria...How does it work? I mean, when I observe that there exist many separate populations of say, finche, common sense doesn't really tell me much about the underlying genetic situation. I have to study it, to find out what's really going on. Common sense doesn't tell me anything.
The argument boils down to stating the subset of genes in one species is greater than the set of all genes of all species, which is obvously false by definition. A clear mis-representation of what I said. How is it usually phrased here? A Strawman?We're talking about a loss of genetic diversity - ie genetic information. Every subsequent speciation leads to less genetic information than before. Your model assumes no mutation can ever exist, "good," "bad," or otherwise. No, it does not; My model does not consider mutations to be a source of information great enough to overcome the loss of information due to speciation. Never does it assume the non-existence of mutations (good, bad, or neutral). This means: IF mutations increase genetic information/diversity, they have never been demonstrated (nor do any biologist hold to such a theory, that I know of) to overcome the loss caused by speciation. The Net Change then is negative.
Additionally, if humans and chimps share 98% of the genetic code, where did the other 2% come from? Bacterial devolution? Degeneration from the fall? Subsets being greater than sets? I'm not sure how this fits in..
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Brad McFall Member (Idle past 5059 days) Posts: 3428 From: Ithaca,NY, USA Joined: |
Please hold while I work out the "redundancy"
Without wedging in either the current ID or Darwinworship sense and more space for genetics, it might be possible to state more than metaphorically,quote:Where "of genes" refers to Johannsen but the set refers to parts of expressible genes susceptible to recombinant techniques only emphasis is on the subjective problem in the word "species" than the objective ostentation of "genes." I know my work below is too confident and written only "for me" just now but I see no reason that if proved by actual statistical information that vitally it is not insignificant to what may prevent abduction to all macro-issues. As for which is the larger number... well that depends through the ordertype whether the FIRST one was manifested in thought as a cardinal of ordinal before...etc.
Mendel’s “Developmental” Bionomial, Boole, and Relational Database Normal Forms - Using 1-D Frieze Patterns to take apart the the “+” in the symbolization of “A+2Aa+a” ABSTRACT--During a period in the history of biology that SJ Gould feels can be phased, organismic biologists realized that they had not properly focused on their level of preference, the organism, as molecular biology advanced. This has resulted in various versions biophilosophy and the plausible relations of contingency to form-making and translation in space among creatures. The cause of this failure in inution of a phenotype is due to failure in the history of logic to extend its line of thought theoretically far enough to be incident with outlines of form-making that might be co-ordinated Cartesiastically. Advances in the molecular nature of inheritance provide a means to support Mendel’s original use of the form of maths’ bionomial through the use “ornaments.” The traditional/classic/standard explanation that a disagreement over adaptive vs non-adaptive traits was the “fall guy” is thus shown false and the actual reason becomes a failure to project theoretical structures into the area of visible comparative ability, subjectively held by biologists. Application is made to the biology of Lichens and a potential niche construction among Cicadas, CicadaKiller Parasitic Wasps and Fowler’s Toads. +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++Olby wrote 93/4:” Added to this evidence is the well-known absence of double letters to represent the pure breeding offspring of hybrids in Mendel's scheme. Thus the three classes in this second hybrid generation (F2) are given the symbols: A + 2Aa + a rather than AA + 2Aa + aa. If these letters refer to the hereditary elements or factors to which Wilhelm Johannsen later gave the name 'gene', we would expect Mendel to have used double letters for each class. To defend Mendel's claim to the gene concept geneticists have indulged in special pleading thus: 'It is but an abridged way of expression. It was perfectly clear to Mendel that those elements occurred paired in homozygotes . . .' Or: 'throughout the papers (and even in his later correspondence with the botanist Ngeli) he has described the three classes of individuals in an F2 as A, Aa and a, evading the unproved doubleness of the "homozygote" AA class.' “ Olby's "Mendel, Mendelism, and Genetics," at MendelWeb This is why I take apart the “+” rather than focus on sexual group selection issues over the sign”\” between pollen and seed etc generalized to any living thing. The reason that the unknown or neutral phenotype arose by the early 70s was because the “doubleness” that differentiates the work of Fisher, Haldane or Wright , (Kimura etc) is false and due to a decomposable situation statistically where a ring field replaces a Cartesian space but because Russell ruled against a particular kind of mathematical proof about “ limits” the narrow focus of Boole’s x^2 only dominated the language of biology such that not even the restrictions of Woodger’s attempts (or others analytically) could be furthered within the organism and instead the plan was frustrated by criticism outside biology (creationism etc) This false double or false positive can be recomposed by splitting the “/” sign into group theory symbols of 1-D Freize patterns when ordinated to actual effective population numbers. The lie is thus given to “overcrowding” as the first and foremost image of the surface of transformative biological potential and the notion(Gould SETH 473) of wedging(Darwin) is shown erroneous because the Mendelization of population genetics with Freize pattern decompositions has increased the place of genetic rotation and revolution (Gould on Goldschmidt and D’Arcy Thompson (Gould SETH 463”He then praises D’Arcy Thompson for locating the phyletic meaning of these ideas in small mutational changes in rates, operating early in development to yield saltational origin of a new adult phenotypes”’’ “)without altering the mathematics of analytic geometry. The prejudice of 2-D is revealed as “saltational origin” and first order logic only in relational databases constricted by the historical relay from Boole’s resticted rules to X^2 only, in “perception.”
In the mean-time I for one have to remain content with my own marginilzation here:
quote: Edited by Brad McFall, : justification
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Modulous Member Posts: 7801 From: Manchester, UK Joined: |
So, is there a reduction of genetic diversity? Not really, the sum population still possesses the full diversity of alleles among its 30,000 genes. However there has been a reduction of genetic diversity as seen in each population.
Well, yes assuming that genetic diversity can never increase or that genetic diversity increases at a rate unable to combat the constant reduction in population size. This undoubtedly happens in some cases, where excessive isolation events can cause bottlenecks which may lead to extinction. The questions is - is this assumption valid and do we see evidence of this? When we look at the evidence do we see any species increasing in genetic diversity with new alleles entering the population?
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Equinox Member (Idle past 5168 days) Posts: 329 From: Michigan Joined: |
I found the bottleneck idea so striking that I put in the errancy wiki here:
Genesis 8:17 - Errancy Wiki Thanks jar for pointing out the "reply" button, and WK for suppling great information on the ways that a past bottleneck is clear to anyone who understands DNA. Have a fun day all- -Equinox
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Equinox Member (Idle past 5168 days) Posts: 329 From: Michigan Joined: |
mjflorestra wrote:
quote: Argh... This has been discussed again and again, and still some miss the past discussion. There are tons of examples of mutations that add information and are beneficial. Even on this thread I earlier posted:
quote: As a recap, here is how a set of mutations can add information, again from an earlier post:
quote:
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Wounded King Member Posts: 4149 From: Cincinnati, Ohio, USA Joined: |
I think that in this instance you are miepresenting mjfloresta's arguemnt. You left out the end of that sentence which specifies that they have never been demonstrated '...to overcome the loss caused by speciation. The Net Change then is negative.' So mjfloresta is not denying that mutations exist that can increase genetic diversity but rather that subsequent to a reduction in diversity during speciation such diversificaton will not replenish or replace lost diversity.
It is a different argument from the traditional one you are addressing. I don't think it is a much better argument, and it certainly isn't one that mjfloresta puts forward anything except his oen hypotheticals to support, but it is distinct. TTFN, WK
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anglagard Member (Idle past 863 days) Posts: 2339 From: Socorro, New Mexico USA Joined: |
What does "common sense" have to do with anything? To you common sense is clearly something different than to me. Under my belief in evolution, as supported by overwhelming evidence, what I said is common sense. What I forgot was unlike 99.9% of all biologists, you are arguing from a position against evolution. Unfortunately, and probably because I am becoming ill with "school-start flu," I was arguing from my position of commmon descent over 3.7 billion years as fact rather than as open to debate. In other words, given that you apparently don't believe in evolution, the logic in my posts naturally does not make sense to you. After this, I will try to argue acknowledging the constraints of your assumptions, so my posts, at least to you, make more sense and are less abrasive. ABE - Given evolution over 3.7 billion years, saying there is less gentic diversity today than there was in any pool of single-celled common ancestors, would be a violation of common sense. But of course one would have to buy into the "given" part of that sentence for such a conclusion to be so blatantly irrational. Sorry, mind too fogged with illness to make myself clear as I would like. Edited by anglagard, : Clarity.
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Philip Member (Idle past 4749 days) Posts: 656 From: Albertville, AL, USA Joined: |
Wounded King writes:
What do you mean "occasional"? I'm stating that the diversity of life requires at least 10 billion of such impossible *beneficial* mutations. EVERY genus and/or species of life seems to me to require at least one to a billion of such *impossible beneficial* mutations.
...At most it (macroevolution) requires, in order to fit the diversity of life we see today, occasional duplications at the gene and higher levels up to that of the entire genome. Wounded King writes:
Granted, the term 'chaotic' may seem a misnomer. (Like an astro-physicist arguing 'matter' vs. 'mass' in the equation E=mcc) But it begs the point. I mean, what non-chaotic driving mechanism could possibly account for ANY raw chromosomal mutations at the genome level? These need not be 'chaotic' although they are likely to be random. Surely your own thoughts betray you, W.K. How can you (an honest research scientist) downplay chaotic gene duplicatons in macro-evolution (A.K.A. 'beneficial mutation')? DISCLAIMER: No representation is made that the quality of scientific and metaphysical statements written is greater than the quality of those statements written by anyone else.
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Equinox Member (Idle past 5168 days) Posts: 329 From: Michigan Joined: |
WK - yes, it is a little different. Sorry about that everyone, and thanks for pointing out my error.
Speciation does not appear to me to be the loss of diversity. If I have 10 alleles for a trait, and a very small sub population because isolated, and, say, it lacks 2 of the alleles, having only 8, and then mutates enough in other loci to cause speciation, then yes it has lost diversity in the original loci, but the whole overall genus has not, since all 10 alleles are still present if you count both groups. In fact, further mutation is very likely to add alleles, perhaps "re-making" some of the missing ones in the new species, or more likley, introducing new ones in both species. For example, after some time the parent population may now have 12 alleles and the new species may have 11 (say, 2 unique and 1 that matches one of the ones in the parent species.). Now even if one of the species goes extinct, the genetic diversity has increased. Looking over geologic time, it's clear that huge amounts of genetic diversity have built up, resulting in the huge genetic difference between a crow and an extremophile. We have plenty of evidence of mutations adding information, and plenty of examples of extinction resulting in lost alleles. Extinction has been the fate of nearly every species that has ever existed, yet the genetic diversity is extremely high now. For instance, the gene for "shorter wings" in the dodo is lost now, but in the same time we've gained alleles for "beautiful buttocks", "eating nylon", "fast algal growth" and more. A great example of a time period with a net loss of genetic information due to extinction would surely be the KT time, and a conversely great time for massive gains in mutational innovation would be, say, the early teriary, or the early triassic. Fun, but perhaps not relevant. Have a fun day- Equinox
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