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Author
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Topic: Proposed algorithm for evolution by ID
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Carl
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Member # 677
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posted 25. February 2003 23:42
I have been working on evolution/ID for several years, and would like to post my proposal for comment and comparison with the evidence.
Very briefly, I propose that macroevolution is a different process than microevolution (I have specific definitions for both terms). Microevolution is just what Darwin described, commonly described as the survival of the fittest. Macroevolution is proposed to occur within a single generation among all organisms within a species, with only the required DNA bases changed. Thus the variation within a species is preserved, and the lack of gradual change (term needs to be defined) in the fossil record is validated.
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Rex Kerr
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posted 26. February 2003 01:17
From your description, I can't tell which of the following may occur under your proposal:
- Divergent speciation by microevolution (1 species -> 2 species)
- Gradual change of speciation by microevolution (1 species -> different species)
- Divergent speciation by design.
If at least the third is a possibility, then your model has a strong and testable prediction. Suppose we find a situation where one ancestor species has given rise to two descendent species. If we look at the sequence similarity between these two species, what we would expect to find is that if we look at noncoding spots in the sequence--those that are not particularly relevant to the function of the organism--the two species would appear to be very recently diverged. However, if we look at important coding regions, the two would appear to have diverged much further in the past (assuming a slow accumulation of changes rather than an instant jump).
Is this a fair characterization / test of your model?
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Carl
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posted 27. February 2003 00:22
quote:
If at least the third is a possibility, then your model has a strong and testable prediction. Suppose we find a situation where one ancestor species has given rise to two descendent species. If we look at the sequence similarity between these two species, what we would expect to find is that if we look at noncoding spots in the sequence--those that are not particularly relevant to the function of the organism--the two species would appear to be very recently diverged. However, if we look at important coding regions, the two would appear to have diverged much further in the past (assuming a slow accumulation of changes rather than an instant jump).
Is this a fair characterization / test of your model?
Yes.
I define microevolution as change of less than about 10 DNA bases, and macroevolution as change of more than 100 bases. Microevolution always occurs, but IMO does not produce new species no matter how long it waits. Macroevolution occurs only at speciation (as defined by paleontologists).
Comparison of two closely related species would, as you said, be a test of this process. Many chemical processes within living things remain the same or very similar. The major controls for the phenotype (physical design) of an organism (the HOX box for example) remain very similar over great varieties of organisms. Thus the gene that places the eye is very similar in drosophila, mouse and human, while the genes that identify the parts must be quite different. The problem is that such detail genes are very difficult to identify, so are also difficult to compare. The highly conserved genes would show no or very small changes, while the genes specifying the changed physical features would have far too many changes for any slow microevolutionary process.
I estimate that it will take close to 20 years before the appropriate testable genes will be identified.
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Rex Kerr
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posted 27. February 2003 03:47
I doubt you will have to wait 20 years. Your model seems to admit statistical tests on the genome level, and we have some very good candidate genomes coming up hopefully within a couple of years. Drosophila melanogaster is already sequenced; the closely related D. pseudoobscura is being sequenced now. Likewise, the nematode worm Caenorhabditis elegans is sequenced, and C. briggsae is in process. Furthermore, the C. elegans genes are already known for many processes that are not perfectly conserved between the two species (i.e. are part of what distinguish them as species).
But we may be able to address part of the point even sooner, namely whether microevolution can lead to speciation. There seem to be quite a few case studies in the literature of what appears to be imminent speciation. For example:
Michalak et al, "Genetic evidence for adaptation-driven incipient speciation of Drosophila melanogaster along a microclimatic contrast in 'Evolution Canyon,' Israel.", PNAS 98:13195-13200.
Haerty et al., "Reproductive isolation in natural populations of Drosophila melanogaster from Brazzaville (Congo).", Genetica 116:215-224.
Ting et al., "Incipient speciation by sexual isolation in Drosophila: concurrent evolution at multiple loci.", PNAS 98:6709-6713. [Note: populations are in Zimbabwe this time.]
A quote from Michalak:
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Previous work has shown that prezygotic sexual isolation and numerous differences in stress-related phenotypes have evolved between D. melanogaster populations in "Evolution Canyon," Israel, in which slopes 100-400 m apart differ dramatically in aridity, solar radiation, and associated vegetation.
. . .
Here we report remarkable genetic differentiation of microsatellites and divergence in the regulatory region of hsp70Ba which encodes the major inducible heat shock protein of Drosophila, in the two populations. Additionally, an analysis of microsatellites suggests a limited exchange of migrants and lack of recent population bottlenecks.
Common to all of these studies is substantial reproductive isolation--not complete, as in the case of traditionally-defined "separate species", but partial.
It is as though we have caught evolution--or design--halfway through the process.
Returning to the Michalak paper, one of the major differences between the two is in a heat shock protein, hsp70Ba, which is implicated in thermotolerance. The two populations--one on the cool north-facing slope and the other on the hot south-facing slope--have differences in this protein. What is the difference?
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Sequencing of the highly conserved transcribed region of the hsp70Ba gene in the Evolution Canyon lines expectedly revealed little polymorphism (not presented here, but see GenBank accession nos. AF 385405-385408). By contrast, the lines were polymorphic for a 1,222-bp insertion in the hsp70Ba promoter. Sequencing identified this insertion as a nonautonomous P element at position 184 relative to transcription start (GenBank accession no. AF377341). This P element intervenes between the second and third of the four heat shock elements (HSEs) located in the hsp70Ba promoter.
The bottom line is that the south-facing population maintains a HSP with higher activity (i.e. no P element insertion) than the north-facing population.
This isn't a very interesting change--basically, the north-facing flies have a partially broken heat shock protein relative to the south-facing flies. But it does at least hint that design hasn't happened yet--otherwise an obvious place to make changes would be in the hsp70Ba sequence itself (which is not observed). Despite this, the populations are effectively reproductively isolated, and seem to be on their way to speciating.
This isn't conclusive, but it is at least suggestive that speciation is probably attainable via microevolution. If this is in fact an example of design-in-process, I presume that your model would make some predictions about what was going on, but aside from the naive ones ("change HSP coding sequences!"), I'm not sure I can make them myself.
Alternatively, this may not be what you mean by speciation. This is speciation as defined by geneticists and population biologists. What is speciation as defined by paleontologists?
Also, as the example here shows, we've got a difference of 1200 bases through a clearly undesigned process (P-element insertion). I think that before we could realistically compare number-of-base-pairs-changed, we'd need to set a more stringent criterion as to what counted--especially given that some sources of mutation (e.g. P-element (transposon) hopping) tend to generate a bunch of different base pairs at once.
Maybe all the bases have to change in the coding sequence for the same essential protein that is responsible in part for the difference between the two species?
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Mesk
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posted 27. February 2003 20:28
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Very briefly, I propose that macroevolution is a different process than microevolution (I have specific definitions for both terms). Microevolution is just what Darwin described, commonly described as the survival of the fittest. Macroevolution is proposed to occur within a single generation among all organisms within a species, with only the required DNA bases changed. Thus the variation within a species is preserved, and the lack of gradual change (term needs to be defined) in the fossil record is validated.
Perhaps you could elaborate a little further on one troublesome point: what exactly do you mean when you say that macroevolutionary change must occur "within a single generation among all organisms within a species, with only the required DNA bases changed"? Do you really mean that the exact same mutations must occur simultaneously in thousands of individual organisms? If so, what do you propose as the mechanism for this event?
Speciation has been observed in both wild and laboratory organisms, so there are plenty of populations that could be used to study your theory. How would you propose that we test your theory against established theories of speciation such as (for instance) reproductive isolation followed by gradual genetic divergence? To be more specific, if you had two populations of Drosophila, one of which was known to have recently speciated from the other, what sort of experiments might you do to test your theory?
Mesk.
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Carl
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posted 28. February 2003 23:26
I would like to see genes identified for different physical characters before 20 years. There could be a breakthrough by science, but as yet I have not been aware of any success in that part of research. Your references certainly bear watching.
Rex said:
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Alternatively, this may not be what you mean by speciation. This is speciation as defined by geneticists and population biologists. What is speciation as defined by paleontologists?
Paleontologists cannot identify species by the breeding test. All they have to work with are the hard parts of the skeleton, and these have to show enough difference to identify before they can be called a new species.
Biologists are convinced that if breeding isolation occurs, it will be only a matter of time until major differences in form will arise, but I am not convinced. It looks to me that they are including in their definition an idea that is not yet proven, and thus avoiding the necessity of proving it.
Evolution cannot occur unless heritable differences can be found, so I prefer to specify species by DNA bases changed. Sometimes a single base change can result in a great phenotype change, but that is still microevolution, which can occur by random mutation. The example of a length of DNA being inserted to cause a change would IMO be the equivalent of a single base change. A single base mutation has been known to cause several other changes in the DNA, so I have proposed that any change of less than 10 bases would still be considered microevolution, but not speciation. Even if the change caused reproductive isolation, that few base changes should not cause major structural changes in the organism, and it could be considered still the same species.
In order to get the amount of change which paleontologists work with in speciation, there would probably be hundreds of bases changed. I agree with Dembski's thoughts on complexity, which indicates that it takes data bits (I forget his terminology) to describe differences. Thus macroevolution or speciation would take more than 100 bases changed. (Changes between 10 and 100 would be subject to investigation.) In the past this type of determination would not have been feasible, but technology is proceeding so rapidly that it should be doable. Transfer or movement of a chunk of DNA would be considered as a single mutation.
From Mesk:
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Perhaps you could elaborate a little further on one troublesome point: what exactly do you mean when you say that macroevolutionary change must occur "within a single generation among all organisms within a species, with only the required DNA bases changed"? Do you really mean that the exact same mutations must occur simultaneously in thousands of individual organisms? If so, what do you propose as the mechanism for this event?
As I have studied the fossil record, and the DNA evaluation of sequences of species, I note that species will exist substantially unchanged from first inception until extinction. No finds of gradual change into the next species have been found, contrary to what Darwin expected to find. DNA studies of Chimps and humans have shown several nearly identical sequences of DNA in the MHC, which controls immunity and identification. I have been told that the number of separate sequences would requires a minimum size population of several hundred breeding pairs. The problem becomes one of preserving a large population through significant changes in parts of the organism. Darwin's proposal of slow and gradual changes would seem at some point to provide breeding isolation in just one or two individuals, which would then go on to become the eventual new species, a very small bottleneck. Also the fossil record does not allow the millions of years that should be required for the random changes to accomplish the new organism. It seems that the only type of change that really agrees with the evidence would be simultaneous change of specified bases in a large population.
I have some ideas about how such a massive change could be done, with the aid of Intelligent Design, but I would prefer to try my proposal to see if it stands up to all the various evidence that has been gathered about the speciation process. If it does, that will be time enough to work on the mechanism. If the algorithm of simultaneous change fits the evidence, then some means of accomplishing that algorithm will be sought, but if the evidence points another way any discussion becomes moot.
[ 28. February 2003, 23:41: Message edited by: Carl ]
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Frances
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posted 01. March 2003 00:54
Carl,
May I suggest that you write up your ideas for consideration of publication in ISCID's journal? Your ideas seem to be very applicable to ID.
In Christ
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Rex Kerr
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posted 01. March 2003 06:18
I suspect that Drosphila will provide the key observations here, and quite possibly already have. With numerous easily-identifiable features such as sex combs, abdominal patterning, size of balancer, and so on, distiguishing between species is fairly easy. Unfortunately, I don't have time to do a thorough literature search to see what is already known about the molecular basis of species-specific differences in morphology. If I stumble into an expert, I'll ask them.
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No finds of gradual change into the next species have been found, contrary to what Darwin expected to find.
Isn't this a bit too strong? There is a nonintuitiveness to the amount of constancy one sees in fossils--although if you think carefully about what you would expect to find and when speciation should occur, it is, I think, less troubling than you'd initially imagine. (More on this below.) But I've seen pages and pages of diagrams of fossil shells that clearly were not the same species from one end to the other, yet had no clear dividing line between them. Unfortunately, I can't find an example on the web now. I seem to recall something similar with tree leaves also. Anyway, I'm quite confident that examples of gradual change exist. There is still a question of why this isn't seen more often.
The problem with seeing widespread gradual changes is that when you find fossils, you're likely to find a fossil of a highly successful organism--one that is competitive in a non-specialized environment, which means that by the time you see it, it has to be well-adapted. You don't expect much change when you're already well-adapted. And it's hard to get gradual change in a very large population anyway--it takes much longer for any change to propagate throughout the species.
However, what you don't see is all the subpopulations that live at the edges of the dominant environment, those that exploit small niches, and so on. Here, alleles can spread throughout the population much more rapidly. If global conditions change, you would predict that some of these groups would be pre-adapted to the new global condition by virtue of already having adapted to a niche that happened to be similar to the new condition. (E.g. high temperature or whatever.) Then you'd expect this small population to take over and displace the stable large one.
And then you'd pick up fossils of the new species, after it was abundant and well-adapted.
It's irritating that this is what one would expect from an evolutionary process with a diverse environment. It makes it much harder to study the interesting details of speciation and change in morphology, because you usually shouldn't get to see the portion of the population that was changing. This obviously doesn't mean that lack of gradual change is evidence for evolution; it just means that lack of widespread gradual change at the species level observed in the fossil record isn't very instructive either way.
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The problem becomes one of preserving a large population through significant changes in parts of the organism. Darwin's proposal of slow and gradual changes would seem at some point to provide breeding isolation in just one or two individuals, which would then go on to become the eventual new species, a very small bottleneck.
This seems intuitively correct, but it turns out to be wrong. In the Drosophila papers I mentioned above, there is partial reproductive isolation between various subspecies. You never need to have just a single pair split off and become their own species; you just need a spectrum of changes where the ends are isolated from each other yet neighbors can breed. (There are some fascinating examples of this in real life; these are often called "ring species". For example, there's some species of warbler or somesuch that spread from India around the Himalyan plateau; the clockwise and counterclockwise arms of the species meet somewhere in Siberia. Anyway, the point is that the two branches are isolated where they meet in Siberia, but never as you travel back from each arm to the origin point.)
Actually, now that I think about it, ring species present an interesting question for your theory, namely: how can it account for ring species at all? I can't see of a good way, although one could speculate that everything we think is a ring species is actually a series of species that we just haven't properly demarkated yet.
Also, I would second Frances' suggestion; it seems to me as though a careful writeup of this would be a good candidate for publication in the ISCID journal. I think it would be a good idea to nail down the speciation thing first, though, namely:
If there is this sharp distinction between species in your theory, how do you account for the blurriness between extant species? (E.g. all the different Drosophila--many of which can be told apart by inspection, and thus presumably meet the species-according-to-paleontoligist test--and ring species, such as the Greenish warbler.) Furthermore, what about the few examples of apparent gradual change that exist in the fossil record?
(It's not necessarily problematic to grant certain types of gradual changes, but I think before you write anything up you should at least decide on a hypothesis and try to support it--e.g. "the changes are always abrupt but we miss some", or "gradual evolution also occurs, but is rare compared to this process", or "this can happen gradually too, like so".)
[ 01. March 2003, 06:21: Message edited by: Rex Kerr ]
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Carl
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posted 01. March 2003 15:27
From Rex:
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No finds of gradual change into the next species have been found, contrary to what Darwin expected to find.
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Isn't this a bit too strong?
I don’t think so. I am aware of changes in snails, such as you mentioned. Gould talked about one such find in his studies, but he thought that it was a hybrid developing. As that takes no new mutations, it does not apply. There are other rare sequences, but there are also other mechanisms other than macroevolution that could apply. I would have to see the details of the change to be able to postulate if they are micro or macroevolution. (My definitions, which I wish I didn’t have to use but I see no alternative, are that microevolution is less than 10 DNA bases while macroevolution is more than 100.)
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However, what you don't see is all the subpopulations that live at the edges of the dominant environment, those that exploit small niches, and so on. Here, alleles can spread throughout the population much more rapidly.
This is what Mayr proposed. However the process must take thousands of years, according to Darwin’s ideas. In such a long period of time, and happening in each species, you would expect at least some fossils. Also the gurus of evolutionary biology talk of mosaic evolution, which as I understand it would be single organs or parts changing. Fossils never show parts of one species and parts of a daughter species in one organism. The speciation seems to rush to completion (how can you say a species is complete in a Darwinian sense ![[Smile]](smile.gif) ), then remain unchanged for a million years or more. I have difficulty blaming environment on such fits and starts in speciation, especially when the species remains unchanged for a million years while ‘the environment’ presumably causes such changes in other species sharing the same environment. This really looks more like a ‘just so’ story than real science.
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For example, there's some species of warbler or somesuch that spread from India around the Himalyan plateau; the clockwise and counterclockwise arms of the species meet somewhere in Siberia.
I am aware of this and other examples of the same. I would again go to my definition of microevolution, and consider that an excellent example of the power of Darwin’s ideas in this category of change.
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If there is this sharp distinction between species in your theory, how do you account for the blurriness between extant species? (E.g. all the different Drosophila--many of which can be told apart by inspection, and thus presumably meet the species-according-to-paleontologist test.
Paleontologists only see bones and teeth, at least normally. Location and number of hairs, and other such soft body differences would not show up. But many of such differences are observed by selection among existing variation. This is not evolution, because no heritable differences from the existing pool of variation is noted. Some of the changes are due to mutation, but mostly of single bases. Most such changes are deleterious, and impede the fitness of the flies. But all of these differences are microevolution, and expected to occur.
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(It's not necessarily problematic to grant certain types of gradual changes, but I think before you write anything up you should at least decide on a hypothesis and try to support it--e.g. "the changes are always abrupt but we miss some", or "gradual evolution also occurs, but is rare compared to this process", or "this can happen gradually too, like so".)
How about this: the changes seen by science in current and recent studies are all microevolution, as they involve selection among existing variation or few DNA bases mutating, all in accordance with Darwin’s theory. Changes seen in the fossil record are macroevolution, changes in many bases. These are two different processes, and microevolution is not involved in paleospeciation just as macroevolution is not involved in the changes we see around us.
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Mesk
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posted 02. March 2003 20:03
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Carl:
I would like to see genes identified for different physical characters before 20 years. There could be a breakthrough by science, but as yet I have not been aware of any success in that part of research.
What exactly do you mean by "physical characters"? In humans alone, genes have been identified which affect a wide variety of physical characteristics, including eye, hair and skin colour, bone density, muscle strength, cardiovascular function, amount of body fat, and many, many others. In experimental organisms the list is even longer: in the worm C. elegans, for instance, systematic screens of mutants have identified genes involved in virtually every aspect of body structure. Similar approaches in the fruitfly and mouse have had similar results. While our understanding of the way some genes map to physical characteristics is far from perfect, there are literally thousands of genes which are known to influence physical structure and function.
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Even if the change caused reproductive isolation, that few base changes should not cause major structural changes in the organism, and it could be considered still the same species.
No, it couldn't. Species are defined as groups of organisms which are capable of interbreeding. If a subgroup of a population is incapable of breeding with the rest of the population, then it is a separate species by definition.
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Thus macroevolution or speciation would take more than 100 bases changed. (Changes between 10 and 100 would be subject to investigation.) In the past this type of determination would not have been feasible, but technology is proceeding so rapidly that it should be doable. Transfer or movement of a chunk of DNA would be considered as a single mutation.
Carl, every child is born with approximately 100 mutations (base changes that were not present in its parents). Could we consider every baby a new species? You and I differ at approximately 3,000,000 sites within our genomes - perhaps that puts us in different phyla?
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Mesk:
Perhaps you could elaborate a little further on one troublesome point: what exactly do you mean when you say that macroevolutionary change must occur "within a single generation among all organisms within a species, with only the required DNA bases changed"? Do you really mean that the exact same mutations must occur simultaneously in thousands of individual organisms? If so, what do you propose as the mechanism for this event?
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Carl:
As I have studied the fossil record, and the DNA evaluation of sequences of species, I note that species will exist substantially unchanged from first inception until extinction.
You need to study more deeply. I'm not a palaeontologist, but I've seen dozens of examples of fossil series in which gradual change is clearly apparent as one moves up the geological record. And with respect to DNA sequence, your statement is completely and utterly wrong, as I showed above: every human being is born with roughly 100 new base changes, and any two humans selected at random will differ at approximately 1 in every 1,000 bases. In other species the genetic diversity is even higher.
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No finds of gradual change into the next species have been found, contrary to what Darwin expected to find.
There are numerous examples of novel species which have arisen by gradual change. The Drosophila literature contains perhaps the largest number of such examples, but there are plenty of reports from other species, including salmon (e.g. Hendry, A.P. 2001. Adaptive divergence and the evolution of reproductive isolation in the wild: an empirical demonstration using introduced sockeye salmon. Genetica 112-113: 515-534.), beetles (e.g. Brown, D.V. and Eady, P.E. 2001. Functional incompatibility between the fertilization systems of two allopatric populations of Callosobruchus maculatus (Coleoptera: Bruchidae). Evolution Int J Org Evolution 55(11): 2257-2262.) and cichlid fish (e.g. Schliewen, U. et al. 2001. Genetic and ecological divergence of a monophyletic cichlid species pair under fully sympatric conditions in Lake Ejagham, Cameroon. Mol Ecol 10(6): 1471-1488.) I strongly recommend that you familiarise yourself with the literature before making these sorts of claims.
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DNA studies of Chimps and humans have shown several nearly identical sequences of DNA in the MHC, which controls immunity and identification.
These sequences are under a form of natural selection known as purifying selection, almost certainly because the sequences in question aid in defence against an ancient, but still present, pathogen. However, examples of interspecies conservation of HLA (human MHC) alleles are rare, and massive diversity of MHC sequences in all species, including humans (who have up to 100 alleles at each HLA locus) is the general rule.
I will also point out that the existence of interspecies conservation of MHC alleles has nothing to do with the minimum population size at speciation, which you go into below. The factor relevant to population bottleneck analysis is the intraspecies diversity of MHC alleles. This is high in humans, but as I show below this is no obstacle to modern theories of speciation.
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I have been told that the number of separate sequences would requires a minimum size population of several hundred breeding pairs. The problem becomes one of preserving a large population through significant changes in parts of the organism. Darwin's proposal of slow and gradual changes would seem at some point to provide breeding isolation in just one or two individuals, which would then go on to become the eventual new species, a very small bottleneck.
This is absolutely incorrect, and suggests a far from complete understanding of the mechanisms of speciation. Speciation does not involve the formation of a new species from a single pair of organisms. Rather, it involves the isolation of an entire population of organisms from the remainder of their species, either geographically or through slow divergence of reproductive behaviour or organ structure (see the articles cited above for examples of such reproductive isolation). The ancestral population of modern humans thus contained more than enough genetic variability to produce the observed numbers of MHC alleles.
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Also the fossil record does not allow the millions of years that should be required for the random changes to accomplish the new organism.
The level of genetic divergence required for speciation takes only a few hundred generations at most; new species have been observed to form in far less time than this. In the salmon article cited above, incomplete but strong reproductive isolation was observed after only 13 generations!
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It seems that the only type of change that really agrees with the evidence would be simultaneous change of specified bases in a large population.
You have not come close to showing this with the evidence you have presented so far, all of which is entirely compatible with speciation via currently accepted means. Perhaps you could do a little research into current models of speciation before developing your theory further?
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I have some ideas about how such a massive change could be done, with the aid of Intelligent Design, but I would prefer to try my proposal to see if it stands up to all the various evidence that has been gathered about the speciation process. If it does, that will be time enough to work on the mechanism. If the algorithm of simultaneous change fits the evidence, then some means of accomplishing that algorithm will be sought, but if the evidence points another way any discussion becomes moot.
Thus far you have presented no compelling evidence to support your hypothesis of speciation via massive simultaneous genetic change. Again, I strongly suggest that you become familiar with the details of modern theories of speciation, and with the literature on observed instances of speciation, before you attempt to cast them aside in favour of an empirically unsupported model which lacks both mechanism and plausibility.
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Carl
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posted 04. March 2003 00:35
Mesk
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What exactly do you mean by "physical characters"? In humans alone, genes have been identified which affect a wide variety of physical characteristics, including eye, hair and skin colour, bone density, muscle strength, cardiovascular function, amount of body fat, <snip>
You are describing the variation which every species has. Darwin did very well on that topic. However, when paleontologists identify species, they note 'markers' by which they can be identified easily. Two adjacent species we might be discussing could be pre-hominid, in the step from knuckle walking to upright motion. A number of bones are shaped differently between the two species as the functions of the body parts dictate. Those characters that are different between species are what I am looking at.
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Even if the change caused reproductive isolation, that few base changes should not cause major structural changes in the organism, and it could be considered still the same species.
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No, it couldn't. Species are defined as groups of organisms which are capable of interbreeding. If a subgroup of a population is incapable of breeding with the rest of the population, then it is a separate species by definition.
Please note that the Darwin definition of species conflates some of the ideas that have been supported by evidence and those that are often thought to be supported but are still in doubt. The idea that as soon as a part of a group becomes reproductively isolated it will inevitably change enough to become recognized morphologically as a new species has never been supported with good evidence. Extrapolation and 'just so' stories are the major source of proof. Please note the definitions that follow.
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Thus macroevolution or speciation would take more than 100 bases changed. (Changes between 10 and 100 would be subject to investigation.) In the past this type of determination would not have been feasible, but technology is proceeding so rapidly that it should be doable. Transfer or movement of a chunk of DNA would be considered as a single mutation.
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Carl, every child is born with approximately 100 mutations (base changes that were not present in its parents). Could we consider every baby a new species? You and I differ at approximately 3,000,000 sites within our genomes - perhaps that puts us in different phyla?
Again, this is the variation found in all species, and each difference belongs in the species. The characters I am referring to are the ones that are noted to change between species.
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Carl:
As I have studied the fossil record, and the DNA evaluation of sequences of species, I note that species will exist substantially unchanged from first inception until extinction.
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You need to study more deeply. I'm not a palaeontologist, but I've seen dozens of examples of fossil series in which gradual change is clearly apparent as one moves up the geological record.
I have been reading with interest the recent big book by S J Gould, The Structure of Evolutionary Theory. As a professional paleontologist, he knows his fossils very well. I recognize that he has views that are a little different from the main stream, but I don't know of anyone that has accused him of doctoring the evidence. Of the very few examples where actual change can be noted in the record, the one that he studies was a hybrid, according to his interpretation. I have heard of other cases where genetic change can also be ruled out. I would have to see, in the other cases, if the 'more than 100 mutation' rule would apply. If not, it would be microevolution.
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I strongly recommend that you familiarise yourself with the literature before making these sorts of claims.
You have quite an impressive list, that looks like what I have seen in the TO FAQ. However, as I have studied those various examples I see either less than 10 bases changed (the best guess I can make) or a jump to a different macroevolutionary species.
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I will also point out that the existence of interspecies conservation of MHC alleles has nothing to do with the minimum population size at speciation, which you go into below. The factor relevant to population bottleneck analysis is the intraspecies diversity of MHC alleles. This is high in humans, but as I show below this is no obstacle to modern theories of speciation.
The point here, according to Li in Molecular Evolution, is that there are several MHC alleles common to chimp and human that have the same bases in non-coding places. They have to be related. And with the number of almost identical alleles the minimum population size to sustain that variety through the several speciations currently known to have occured must be in the order of at least several hundred.
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The level of genetic divergence required for speciation takes only a few hundred generations at most; new species have been observed to form in far less time than this. In the salmon article cited above, incomplete but strong reproductive isolation was observed after only 13 generations!
The species found in the fossil record have many differences between successive species. Each difference should require many DNA base changes. The more complex the change the more bases it should require to describe it. And the more bases that must be changed the more time it takes natural selection to find and prove them. Reproductive isolation with no other morphological changes could require only one or two base changes. Remember, I am not concerned with microevolutionary speciation. Darwin hit that process just right. It is the origin of novel characters that is the problem.
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You have not come close to showing this with the evidence you have presented so far, all of which is entirely compatible with speciation via currently accepted means. Perhaps you could do a little research into current models of speciation before developing your theory further?
My research seems to show me something different than yours does. Perhaps my different view of what constitutes micro and macroevolution might have something to do with it, but this view is part and parcel of the proposal. You cannot consider a different idea in the light of the original idea, but must rely on the evidence.
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kyle7
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posted 11. March 2003 00:21
Carl,
I would like to refer you to a thread I started a while back.
ID Predictions Made by an Engineer
Like you, I see a difference between micro and macro evolution. I am an engineer who has a problem with the assumption that is made by biologists -- that significant change in fitness can be achieved by microevolution. Without significant changes in added fitness, the multitude of microevolutionary changes don't have a chance of coalescing into a single genome. Basicly, the UPB (upper probability bound) is reached.
I would say that the vast number of mutations required to construct advanced lifeforms would reduce fitness or be neutral given the complexity of the systems involved. In essence it is like the mousetrap problem (an IC system). The problem is that if one would envision evolutionary development, the vast number of paths would result in dead ends. If we compare the number of possible paths starting out in the direction leading to complex biological systems, to the number that actually lead to complex systems, we reach the UPB. It is similar to the 2nd Law of Thermodynamics(SLoT). Although we can envision ways to violate the SLoT, the violations don't occur due to the low probability. The vast number of states favor local equilibrium or local quasi-equilibrium compared to the few possible states resulting in the violation. So in essence, we can argue that there is a "Second Law" principle acting on biological systems, thus preventing macroevolution.
Frances, I know that you will provide a number of links to argue against this, but I would say that your examples are cases that are designed into biological systems to provide robustness in the design.
[ 11. March 2003, 00:28: Message edited by: kyle7 ]
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Frances
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posted 11. March 2003 11:27
Kyle: Frances, I know that you will provide a number of links to argue against this, but I would say that your examples are cases that are designed into biological systems to provide robustness in the design.
Designed by what? Please show how you reached your conclusions.
As far as the SLOT, it cannot be 'violated' but similarly to the SLOT, in open systems entropy can decrease locally. In fact this is shown by the work of Adami that natural selection/mutation leads to an increase in complexity/information in the genome.
Seems to me that natural forces can explain many of the observed robustness etc of its 'design'. In fact the presence of degenerate systems rather than redundant systems is something not found outside biology. All in all I have yet to see not only an assertion of ID but also a pathway of ID. But if I understand Dembski correctly, ID does not really deal in pathways. So how can we compare an ID hypothesis with a scientific hypothesis I then wonder?
Perhaps Kyle or Carl can propose some ways? Perhaps Kyle can show some of the underlying probability calculations that led him to reject macroevolution?
[ 11. March 2003, 11:28: Message edited by: Frances ]
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brauer
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posted 11. March 2003 15:37
FYI: In the course of about 3 weeks of adaptation to a novel environment, I get yeast strains that have significantly better ways of doing things than their ancestor. They often have strikingly different morphologies and metabolisms. The course of this adaptation cannot be reversed. The substitutions in this population occur about at least once every 3 days or so.
A year of adaptation at this rate will equal "macroevolution" according to your definition. That is, the adapted population will have:
- more than 100 "differences" (including SNPs, indels and translocations) from the ancestor;
- inability to breed with the ancestor;
- different morphology from the ancestor;
- different metabolic and gene expression network structure from the ancestor.
At what point has the "macroevolution" happened?
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kyle7
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posted 16. March 2003 03:39
Frances,
The second law does apply to open systems. Engineers use it all the time. You need an auxiliary device to allow a localized decrease in entropy. This auxiliary device must have all the mechanisms to allow the specified application of energy. A life-form has all the information in the genome that specifies the boundary conditions and the detailed processes to construct the life-from. However, when naturalists try to use NeoDarwinism to explain the development of new systems, they run into problems with the Second Law of Thermodynamics because they lack an auxiliary device that specifies the precise application of energy in the construction of the new system. The stochastic nature of the Darwinian mechanism does not allow the specification needed for new systems to develop.
Matt,
If you gave your yeast culture to another biologist to examine, what would he call the cells? He would call the culture a strain of yeast. One problem with NeoDarwinian naturalism is that it does not promote thinking. You look at the changes in the yeast and say, "Darwinian evolution did it." The ID biologist would look closer at the details searching for the mechanism within the cell that causes the changes. He would predict that there is a whole level of complexity regarding the cell yet to be discovered that explains the robustness of life. As a truck can shift gears to adapt to road conditions, so a yeast culture can shift gears by adapting to a modified environment. As we learn more about the dynamic nature of the genome and the cell, the argument for design will become stronger.
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