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Author
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Topic: Speciation
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warren_bergerson
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Member # 262
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posted 12. May 2004 10:01
John,
If I any interpreting your comments correctly, then you are saying that speciation, at least in vertebrates, is due to one and only one mechanism and process. If that is what you are saying, then I would agree that your hypotheses is testable either by showing the proposed process and mechanisms does not produce speciation or by showing that speciation can be produced by some alternative process or mechanisms. Your hypotheses would, for example, be disproved if interbreeding between two groups produced embryo’s that always died in the third month of the development process. Right?
However, even if your hypotheses was confirmed by testing, I am not sure that such a finding would disprove modern Darwinian or neo-Darwinian theory. It would not, IMO, be particularly difficult to incorporate findings supporting your hypothesis into the modern descriptive form of Darwinian theory.
Rex,
I read the examples you posted, but, IMO, they do not satisfy the requirement for scientific testability. First, your predictions appear to depend in large measure on ‘subjective acceptability’ rather than on objective interpretation of an explicitly formulated theory. At least IMO, you can’t have objective independent testing if predictions must first be approved by the supporters of the hypothesis.
Second, finding any or all of the listed predictions to be wrong would not result in the falsification of modern Darwinian theory. The modern theory could simply be modified to fit the new facts.
IMO, there is nothing inherently wrong with the ability to successively modify hypotheses to reflect accumulating facts. In fact, I think successive approximation is an important positive feature of a type or class of scientific hypotheses. However, again IMO, a distinction should be made between hypotheses that simply change to reflect new facts, and hypotheses that are improved and refined.
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nosivad
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Member # 767
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posted 12. May 2004 20:08
Rex Kerr
You cannot correct my mistakes because you, like everyone else, knows absolutely nothing for certain about the process of macroevolution (speciation). For you to just repeat Darwinian dogma means nothing to me, because that is all that it is. The failure to transform species gradually means to me that they were produced instantaneously. I presented the evidence for that in the paper "The Case for Instant Evolution". Comment on the evidence instead of just continuing to support an hypothesis that never had any credibility in the first place. I am obviously wasting my time if all I can ellicit is the same old Darwinian aimless, purposeless scenario. It just won't wash anymore.
Warren
You obviously have misinterpreted just about everything I have published. There is no conceivable way that Darwinism can be patched up or rescued from its inevitable oblivion. The most remarkable thing to me is that anyone any longer gives it any credibility whatsoever. It was dreamed up by a pair of Victorian naturalists who happened both to have read Lyell and Malthus. It is the most thoroughly tested and failed hypothesis in the history of science. What more can I say?
[ 12. May 2004, 20:16: Message edited by: nosivad ]
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Rex Kerr
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Member # 632
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posted 13. May 2004 01:41
Warren, scientific theories must make predictions, and they must be falsifiable, but there is no reason why the most detailed predictions also have to be the ones that, if they fail, will falsify the theory.
So your criticism is largely misguided. I haven't seen anything from you that is anywhere near as detailed as what I've already described. I'm not here to teach a course on evolutionary biology. If you want more detail, read a textbook on evolution (preferably a mathematically oriented one). Or if you want to induce me to come up with predictions with greater specificity, come up with some of your own and I'll match the specificity and detail. Explain where the "subjective acceptability" comes in, and I'll fix that, too.
nosviad, I was intending to show that your question, "How can the alteration of the habitat destroy organisms that are capable of evolutionary change? Shouldn't they be responding to such alterations?" was only a problem for your theory (and maybe Warren's?), not for "Darwinism", as you like to call it. I left off that proviso in my reply to J@MIT since I assumed that he was speaking of modern evolutionary biology (and that you were also, given your "only reasonable conclusion" statement, which means that you were ruling out a Darwinian explanation).
[ 13. May 2004, 01:42: Message edited by: Rex Kerr ]
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nosivad
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Member # 767
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posted 13. May 2004 07:28
Rex Kerr
I don't have theories. I have two closely related and untested hypotheses. Actually, the Prescribed Evolutionary Hypothesis is already receiving support from studies on yeast and coelenterates. There is still no compelling evidence that evolution ever involved the environment in the emergence of new higher life forms.
"Evolution is in a great measure an unfolding of pre-existing rudiments."
Leo Berg, Nomogenesis page 406
Needless to say, that which has been revealed by unfolding must already have been there. I just wish Berg had used was instead of is in the above quote. Once the realization that evolution is no longer occurring is accepted, everything falls into place, at least for this investigator. Forgive me for my obvious heresy, as I am convinced that is how it is perceived by the adherents to "the standard evolutionary model" (neoDarwinism).
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warren_bergerson
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Member # 262
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posted 13. May 2004 13:55
John,
At least IMO, modern Darwinian theory cannot be both a religion and a testable-falsifiable scientific hypothesis. It may be neither. My impression is that modern Darwinian theory is something like a descriptive hypothesis consisting of the set of currently known facts regarding evolution and the currently accepted interpretations of those facts.
If your predictions prove correct, it might be argued that Type 1 speciation is due to the mechanisms you propose but that Type 2 or apparent speciation is due to traditional Darwinian mechanisms. Such an interpretation, it could be argued, is completely compatible with modern Darwinian theory.
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nosivad
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Member # 767
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posted 13. May 2004 16:26
Warren
There is no modern Darwinian theory. There is only a failed Darwinian hypothesis. Theories are hypotheses that have been verified to some extent. Darwinism, like Lamarckism, fails to qualify. I'm sorry to seem so arbitrary but that is what it boils down to.
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RBH
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Member # 380
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posted 13. May 2004 19:03
warren_bergerson wrote quote:
My impression is that modern Darwinian theory is something like a descriptive hypothesis consisting of the set of currently known facts regarding evolution and the currently accepted interpretations of those facts.
And it's my impression that quantum mechanics is something like a descriptive hypothesis consisting of the set of currently known facts regarding sub-atomic entities and the currently accepted interpretations of those facts.
RBH
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warren_bergerson
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Member # 262
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posted 14. May 2004 08:49
There are some interesting comparisons between quantum mechanics and Darwinian evolution theory. It would, however, seem somewhat dubious to suggest the two are on an equal or even similar footing.
Both quantum mechanics and evolutionary theory are efforts to address complex causal relationships. In both instances, the available data does not appear to be compatible with the simplistic Newtonian form or model of causation. While both situations involve ‘hypothesis formulation problems’ the types of solutions adapted seem very different. Physicists in order to address the complexity associated with quantum mechanics accepted the new stochastic form of predictive hypothesis. Evolutionary biology, by contrast, apparently abandoned falsifiable predictive hypotheses and went with the highly modifiable, highly adaptive descriptive form of hypotheses.
Viewed from a distance, there might not appear to be a great deal of difference between a single descriptive ‘theory’ which is continually be modified to reflect new knowledge, and a series of testable, falsifiable, hypotheses that are proposed-tested-falsified-replaced. However, at least IMO, the falsify and replace approach is real science and the descriptive theory approach is not.
At the very least, John Davison has demonstrated that it is possible to formulate and explicitly express testable, falsifiable, predictive hypotheses addressing the subject of speciation. The semi-meiotic is not the only speciation hypothesis that could be formulated that would satisfy the ‘explicitly expressed, testable, falsifiable predictive hypotheses’ criteria. Where are the ‘Darwinian hypotheses’ that fit these requirements?
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nosivad
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Member # 767
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posted 14. May 2004 11:23
Warren
The Darwinian hypotheses DO fit the requirements you have mentioned and they have failed every test that has been made. Instead of admitting that failure, the Darwinians have stopped testing, confident that they have to be right as any alternative view of the universe is unacceptable. It is raw naked ideology.
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Rex Kerr
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Member # 632
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posted 14. May 2004 23:42
Darwinian evolution predicts that the features that are most important for survival will change most rapidly. It predicts that genes important for those features will change rapidly also. In particular, it predicts that nonsynonymous mutations (those that change amino acid composition) will be kept more frequently than synonymous mutations.
A key difference between humans and primates, and between primates and other mammals, is the size of our brains. Given the rapid increase, a Darwinian model would assume that there is considerable selective pressure for that increase. Therefore, genes that control brain size should show an excess of nonsynonymous mutations.
Kouprina et al., "Accelerated Evolution of the ASPM Gene Controlling Brain Size Begins Prior to Human Brain Expansion", PLoS Biol. 2004 May;2(5):E126. Epub 2004 Mar 23.
quote:
Primary microcephaly (MCPH) is a neurodevelopmental disorder characterized by global reduction in cerebral cortical volume. The microcephalic brain has a volume comparable to that of early hominids, raising the possibility that some MCPH genes may have been evolutionary targets in the expansion of the cerebral cortex in mammals and especially primates. Mutations in ASPM, which encodes the human homologue of a fly protein essential for spindle function, are the most common known cause of MCPH. Here we have isolated large genomic clones containing the complete ASPM gene, including promoter regions and introns, from chimpanzee, gorilla, orangutan, and rhesus macaque by transformation-associated recombination cloning in yeast. We have sequenced these clones and show that whereas much of the sequence of ASPM is substantially conserved among primates, specific segments are subject to high Ka/Ks ratios (nonsynonymous/synonymous DNA changes) consistent with strong positive selection for evolutionary change.
So we not only have a detailed prediction based on Darwinism (or, rather, on modern evolutionary biology), but the prediction was confirmed.
In fact, never finding molecular evidence of selective pressure would come very close to falsifying Darwinism. Unless a mechanism could be found that somehow prevents it, the Darwinian prediction is that genes under strong selective pressure must (in the stochastic sense of "must") accumulate nonsynonymous mutations faster than synonymous ones.
So there are Darwinian mechanisms at work during speciation, and these apparently lead to primary differentiating characteristics between species.
In fact, we expect positive selection (measured by nonsyn/syn ratios) to cause speciation, either by accident (in allopatric scenarios) or because speciation is selected for (in sympatric scenarios). Either way, we expect to find evidence of positive selection in some of the genes responsible for incompatability between species.
Presgraves et al., "Adaptive evolution drives divergence of a hybrid inviability gene between two species of Drosophila", Nature. 2003 Jun 12;423(6941):715-9.
quote:
Here we identify a gene that causes epistatic inviability in hybrids between two fruitfly species, Drosophila melanogaster and D. simulans. Our population genetic analysis reveals that this gene--which encodes a nuclear pore protein--evolved by positive natural selection in both species' lineages.
This is another detailed prediction from modern evolutionary biology that has been confirmed!
So, to Warren: yes, there are detailed falsifiable predictions made. I've shown some of the ones that succeeded. There are numerous others.
And to nosviad: if you've read this post, you will notice that the claim that "The Darwinian hypotheses...have failed every test that has been made," is false. Now that you are aware that it is false, I trust you will at least include a qualifier in your future statements. The claim of "every" is unsupportable.
(Most weaker claims about evolutionary theory failures are also unsupportable. But I've only shown one example here, so one who has read this post (and not refuted it on substantive grounds) would only knowingly be propagating a falsehood if they continued to claim "every" test was a failure.)
[ 14. May 2004, 23:51: Message edited by: Rex Kerr ]
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nosivad
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posted 15. May 2004 07:23
Rex Kerr
If you are going to support Darwinism you must provide an example of how selection has produced a new species. That has not yet been done. Furthermore, you assume speciation is in progress right now as if that were an established fact. It is very much in question, as I and others have indicated. The simple truth is that the experimental transformation from one species to another has never been demonstrated through the agency of sexual reproduction. For all practical purposes Darwinism is not and has not been an experimental science. I have proposed an alternative mechanism and until it is proved to be inadequate I will continue to consider it viable. Incidentally, even if the Semi-meiotic Hypothesis fails to produce a new species, it does not mean that such a device was not instrumental in the past. I find it very significant that scrambling the chromosomes of yeast can result in evolution in reverse. It may one day be possible to apply the same techniques to vertebrates to produce our ancestors as well. Of one thing I am now certain. Natural selection of randomly generated genetic change has never played a significant role in the evolutionary process. That is what has led me to the only conceivable alternative, namely, the Prescribed Evolutionary Hypothesis which is in complete accord with the Semi-meiotic Hypothesis.
[ 15. May 2004, 07:25: Message edited by: nosivad ]
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warren_bergerson
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posted 15. May 2004 07:50
Rex,
You bring up an important point. Evolutionary biology and evolutionary biologists clearly do generate predictive scientific hypotheses with testable predictions. Many of these hypotheses and predictions, as you note are confirmed by testing. There are also many instances predictions are not confirmed and where the hypotheses are rejected and replaced with hypotheses that fit the fact. The issue here, at least IMO, is not whether evolutionary biologists perform scientific analysis.
The question, IMO, is whether these testable hypotheses and testable predictions arise from 1) a predictive scientific theory of evolution or 2) a descriptive body of knowledge. A second interesting question, somewhat beyond the scope of this thread, concerns the logical form of the predictive hypotheses being generated in evolutionary biology. Do these hypotheses predict evolutionary change based on fixed mechanical processes, or are they predictions generated using goals, functions, and purpose, combined with the intelligent processes and mechanisms needed to achieve these goals. An interesting question, but beyond the scope of this thread.
The fruit fly example has some interesting implications. To begin, since species are known to exist, all hypotheses need to predict the existence of some type of physical species boundary mechanism. The finding that a species boundary can involve changes in a single gene would confirm my suggestion that species boundaries can be very simple.
If species boundaries involve simple genetic changes, then it seems reasonable to predict that the mutations involved in producing these changes would be relatively common. This in turn would lead to the prediction that it should be relatively easy to artificially create species boundaries and new species. Furthermore, it would appear reasonable to predict that speciation would be a relatively common occurrence in nature. None of these predictions appears to be confirmed by observation. Does this mean Darwin has been falsified?
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Rex Kerr
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posted 15. May 2004 14:49
The examples I gave above, regarding nonsynonymous/synonymous mutation ratios as indicators of positive selection, are the result of a predictive scientific theory, not of a descriptive body of knowledge. As in all biological sciences, much of evolutionary biology concerns descriptive knowledge only, but there are definitely predictive theoretical components as well, or we'd have no idea how to go look for positive selection (for example).
Also, I think the "reasonable prediction" of ultra-rapid and common speciation is missing some important data. In order to predict the rate of speciation based on mutations to genes, we need to know (1) how many genes can induce speciation (and the minimum number needed), (2) how many changes need to be made to one of these genes, (3) the probability of each of these changes, and (4) the impact on fitness when some but not all changes have been made.
Unfortunately, we don't have this detailed level of understanding yet, so it's very hard to compare rates of speciation with predicted rates. Hopefully in the coming decades, the genetic mechanisms that maintain reproductive barriers between species will be more fully characterized, and then we'll be able to do the calculation.
nosviad seems to have a basic misunderstanding of the nature of scientific evidence. Of course, it would be a tour de force to document in detail all changes and mechanisms for those changes that were involved in a speciation event, and demonstrate that they were entirely characteristic with modern evolutionary theories. (Probably with some small tweaks, as is always the case with theories in biology.) But one of the major reasons we can do scientific research is that this isn't always necessary! Instead, we can make predictions about what should happen assuming various hypotheses; if these predictions differ, then we can reject those hypotheses that fail to make appropriate predictions, and gain confidence in those that succeed.
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nosivad
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posted 15. May 2004 17:41
I can assure Rex Kerr or anyone else that I have an excellent understanding of what constitutes scientific evidence. I regard that comment as a gratuitous slur and Kerr should apologize, especially now that we presumably have new standards of civility on brainstorms. I was an experimental scientist, not an armchair theoretician like Stephen J. Gould, Richard Dawkins, Ernst Mayr, William Provine and the many others who preferred speculation to the laboratory bench. The four I mention share the following common features. None ever did an experiment to test their common Darwinian beliefs. With the possible exception of Mayr they are professed atheists which means by definition that they have rejected purpose or goal in evolution. Collectively they have produced an enormous amount of literature, nearly all of which was was presented as if there were never any critics of the Darwinian scheme. They are all known primarily as evolutionary theoreticians, having virtually no experimental or practical field credentials. Mayr, Gould and Dawkins, in particular, have presented their convictions with supreme arrogance, Mayr describing himself as a "dyed-in-the-wool Darwinian", Gould characterizing intelligence as an "evolutionary accident" and comparing evolution to a "drunk reeling back and forth betwen the bar room wall and the gutter." Dawkins is in a class by himself with such fantasies as "Climbing Mount Improbable".
By way of contrast the investigators on whom my own work securely rests were first and foremost professional scientists, Bateson and Goldschmidt experimental geneticists, Broom and Schindewolf hands on paleontologists, Leo Berg a field ichthyologist and zoogeographer, and Pierre Grasse a general zoologist with an encyclopedic command of his field, a characteristic he shared with Leo Berg. They all independently saw through the Darwinian scheme and presented their evidence with consummate clarity in relatively few but highly significant publications, publications that for obvious reasons have been ignored by both the Darwinian and the Fundamentalist factions. I find it difficult to believe the typical Darwinian has even read their works. If they had they would have abandoned Darwinism long ago as I did.
"No sadder proof can be given by a man of his own littleness than disbelief in great men"
Thomas Carlyle
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Rex Kerr
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posted 15. May 2004 20:14
I am trying to be as polite as possible, but I am going to err on the side of accuracy, not on the side of politeness. This is, after all, what scientists are supposed to do.
So if you, or anyone else, makes a comment that shows a basic misunderstanding of the scientific process--or has double standards where evolutionary science has to produce extraordinarily solid and complete evidence relative to other disciplines--then I either have to conclude that the person making the comment misunderstands or is willfully misrepresenting the scientific process.
Let's look at some examples.
There are theories of continental drift causing separation and merging of continents. Do we conclude that they are all an utter failure because we have not observed two continents merging in recorded human history, and have likewise failed to merge continents?
There are theories of star formation. These must all be a failure because we have never created a star.
There are theories of hurricane formation. Yet we cannot predict exactly when hurricanes will appear, so these theories must be an utter failure too. (Never mind that these theories also explain why we can't predict.)
Mendel's experiments with peas, and all phenotypic genetics since, must also be regarded as a complete failure since we cannot say yet precisely how all the steps work between a genetic defect and peas being yellow vs. green.
And so on.
To claim that evolutionary biology can only be supported by a complete tale of all selective pressures causing all genetic changes resulting in speciation that establishes a complete physiological reproductive barrier--and note that we have offered almost everything less than that with you rejecting it as incomplete to the point of worthlessness--is to abandon the incremental, provisional, and indirect method of gaining knowledge about natural phenomena.
Now, it just so happens with whole genome sequencing that within a couple of decades we probably will be able to fully document a speciation event, but the point I am trying to make here is that this is not the only way to support modern evolutionary theories.
So I stand by my original statement, with the following proviso: perhaps you understand the scientific method well, but simply failed to apply your knowledge of it when you made your comments above. If this is the case, I apologize for my overly broad characterization and hope you are more careful in the future.
[ 15. May 2004, 20:14: Message edited by: Rex Kerr ]
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