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Author
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Topic: Prof. Davison's Challenge to NDE
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John A. Davison
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Member # 1425
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posted 29. May 2006 13:27
It was a Darwinian, Theodosius Dobzhansky who proposed a perfectly satisfactory definition of species. If the hybrid produced as the progeny of two different parents is sterile, they are different species. There is nothing either vague or gradual about this clear physiological definition. It is sound experimental biology and requires no further modification or elucidation.
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Bruce Fast
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Member # 924
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posted 29. May 2006 16:52
"If the hybrid produced as the progeny of two different parents is sterile, they are different species."
Zachriel has suggested that with some hybrids, the offspring are "less fertile", I believe he could also add "often but not always infertile." Is Zachriel in error? If the hybrid of variety A and variety B produce sterile offspring 80% of the time, but not 100%, are these varieties of the same species, or of two different species?
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Zachriel
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posted 29. May 2006 18:04
Bruce Fast: "I remain puzzled at what I see as Dr. Denton's strongest case for PEH, that the evolutionary tree was deveoped from the trunk first (domain, to kingdom, to phylum ... )"
Back to scale invariance...
Look at a seedling tree. It has a very small stem that might have two or three small shoots. Consider the end of each shoot to be a species. As the tree grows, each shoot becomes the branch of other shoots. Later, when we look at the tree, we wonder why there are two or three large branches and it doesn't look as if any were created recently. All the new growth are shoots on established branches.
Now consider life. At some time in the distant past, a few species survived and eventually diversified into a wide variety of different forms; Chordates, Echinoderms, Molluscs, Crustaceans. At that distant time, they were each just a shoot of some earlier organism. Just another species.
(Unlike 'species', 'phyla', 'family', and so on, are somewhat arbitrary divisions in the nested hierarchy. It depends what you consider to be a main branch.)
Bruce Fast: "Why do we not see new phylums, orders, classes etc. pop up with the kind of pattern one would expect of a random event"
You probably do see new orders, classes, and so on. You just don't recognize them as such. They're just species today. Perhaps one day they will amount to something, but you can't tell.
However, you wouldn't see them form randomly in a scale-invariant architecture. Most shoots are just shoots. Some will eventually form branches. Only a few will grow into large branches.
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Zachriel
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posted 29. May 2006 18:14
Dobzhansky: "If the hybrid produced as the progeny of two different parents is sterile, they are different species."
Dobzhansky's original definition of species was suitable for his particular specialty, but he
later modified his definition to more properly reflect what happens in nature.
Bruce Fast: "If the hybrid of variety A and variety B produce sterile offspring 80% of the time, but not 100%, are these varieties of the same species, or of two different species?"
It doesn't matter what you *call* them. What matters is what actually happens. Darwin realized that (what biologists called) species had to blend with (what biologists called) varieties in order to be consistent with his Theory of Evolution. So, being the careful observer that he was, he noted numerous instances of hybridization between species, and how fertility of these hybrids varied over a gradient.
(Darwin lacked a valid theory of genetics, so he was wrong in some particulars. Nevertheless, Origin of Species is a profoundly reasoned and seminal scientific work.)
[ 29. May 2006, 18:15: Message edited by: Zachriel ]
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John A. Davison
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Member # 1425
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posted 29. May 2006 19:12
Nothing that Darwin proposed ever had anything whatsoever to do with the title of his book. Everything he proposed had to do only with the formation of varieties, varieties that never transcended the species barrier. Neither natural nor articicial selection can produce new species. To blindly insist that they can or ever did is without foundation. If they could it would have been demonstrated experimentally long ago.
Here is another challenge which I predict, like all my others, will also remain unanswered. When in the process of creation did the Creator or Creators hand over the reins to Nature to complete the task? My unequivocal answer is NEVER.
"The struggle for existence and natural selection are not progressive agencies, but being, on the contrary, conservative, maintain the standard."
Leo Berg, Nomogenesis, page 406.
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Supersport
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Member # 1989
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posted 29. May 2006 20:30
I posted this challenge at a debate forum and got this response:
"It seems some would have us believe this idea touted by University of Vermont biologist John Davidson that evolution has stopped. He claims that there have been no new species since Homo sapiens. This of course is complete nonsense."
His examples were the following:
Arctic Fox and Polar Bear -- 200,000 years
Daelie Penguins -- 60,000 years
American Bison -- 100,000 years
He also mentioned blind mole rats, sticklebacks, Lake Victoria Cichlids
S
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Supersport
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Member # 1989
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posted 29. May 2006 20:40
By the way, I gave the actual link to this challenge...I notice that the responder re-worded the challenge and got your name wrong. But this was his response none-the-less. S
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Jehu
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Member # 1981
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posted 29. May 2006 21:20
What makes the Polar Bear a new species? I understand Polar Bear/Grizzly Bear hybrids have been found in the wild. Of course, I don't think hybrid is the right word for it. It is more a mixed breed I think.
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Bruce Fast
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Member # 924
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posted 29. May 2006 22:59
Supersport, please understand that as this brainstorm is specifically about Dr. Davison's challenge to NDE, we must also use his definition of species -- the classic definition.
Recent news clarifies that the polar bear and grizzly bear are likely the same species based upon the classic definition. (As the resultant bear is dead, it cannot be confirmed whether it is fertile.)
The bison, on the other hand, is clearly a bovine. Interbreeding between the bovine (cow) and the bison quite readily produces fertile offspring.
I am unfamiliar with the other animals you mention, however, within this context, unless there is clear evidence that hybridizing is unsuccessful, or that the resultant hybrids are infertile, one must assume that the animals do not meet the classic definition of species.
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Bruce Fast
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Member # 924
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posted 29. May 2006 23:11
Zachriel, quote:
You probably do see new orders, classes, and so on. You just don't recognize them as such. They're just species today. Perhaps one day they will amount to something, but you can't tell.
However, you wouldn't see them form randomly in a scale-invariant architecture. Most shoots are just shoots. Some will eventually form branches. Only a few will grow into large branches.
This "slow drifting apart" view of the development of the tree of life again makes total sense when one envisions an NDE world. However, this is certainly not the picture that forms in my mind as I read about biology.
I read about the cambrian explosion. Prior to the explosion there seems to be virtually no evidence of any multi-cellular animal life. (There does seem to be some sketchy evidence that some soft-bodied animals predate the cambrian.) During the layering in the bluegrass shale, and the chineese site, there seems to be a very rapid development of somewhere between 25 and 100 phila. (There seems to be considerable debate about the count, which I don't truly understand.) No one seems to suggest that any biologist who was transported back to 10 mil after the beginning of the cambrian would say, "hey, there's about 50 species here". No, it appears that the biologist transported back in time would recognize the variety as "phila".
By the same token, if a biologist were transported back to say 150 mil, (I think it was around 250 mil that the classes popped into the scene, but I'm just talking off the top of my head -- the idea rendered is correct,) he would see all of the classes that we see today. He would not look at these classes and identify them as families. Yet if that biologist was transported back to 300 mya, he would identify very few classes.
If phyla were just species that slowly drifted apart, if orders, classes, families were just species that slowly drifted apart, then I would find NDE to be much more compelling. However, I have found no biological discussion that describes it this way.
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John A. Davison
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Member # 1425
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posted 30. May 2006 07:10
Nothing in the geological record supports gradualism at any level from species right on up to phylum. Every taxon that ever appeared appeared instantaneously and without obvious transitional intermediates. That in no way speaks against reproductive continuity but it is lethal to every aspect of the Darwinian model. It is precisely what the PEH can predict.
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Melvin H. Fox
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Member # 1684
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posted 30. May 2006 08:28
Zach,
Thank you for your lucid explanation of reproductive isolation. I understand these ideas much better now. My background is mathematics and I must confess my uneasiness with respect to the slippery definition of species you have offered. I am used to terms being well defined. But if this is the accepted practice in biology then I will adapt for our discussion.
You peak my interest when you speak of a continuum. Let’s say we have two populations separated in such a way as the gene flow between them is low to the extreme. Further suppose that this separation extends over countless generations. Will these two populations eventually become reproductively incompatible? In other words, is the limit of this process total incompatibility? If so, has this occurred? If it has, when and where did it occur?
Forgive my naiveté.
-Mel
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John A. Davison
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Member # 1425
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posted 30. May 2006 11:08
There are instances in which separated populations become incompatible when the extremes are tesed but they still may be experiencing gene flow along the connections between them. These are trivial evolutionary situations which have no bearing whatsoever on the production of novel inventions. They are blind alleys at best.
I agree entirely with Julian Huxley's and Robert Broom's shared conviction that a new Genus has not appeared in two million years. I have further extended this by challenging anyone to document a new species or any higher taxonomic category in historicsl times. None of my several challenges have even been acknowledged let alone answered. Like Berg, Goldschmidt, Broom, Schindewolf, Bateson, Mivart and Grasse, I too do not exist. It is an old story in the evolutionary literature. We are not allowed to exist because it would be fatal to the Darwinian model if we did!
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peter borger
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Member # 722
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posted 30. May 2006 11:16
quote:
Nothing that Darwin proposed ever had anything whatsoever to do with the title of his book.
I completely agree.
We cannot understand biology from natural selection. I have demonstrated that here for the genetic redundancies. To argue that natural selection is a mechanism, a force that drives speciation is like argueing that phlogiston is driving combustion.
The issue is, NS is unable to explain the existence of genetic redundancy required for species' robustness, so why would it be relevant to explain speciation?
As argued, speciation "just happened" due to genetic elements with the ability to reshuffle genomes. These elements qualify as genomic redundacies as they do not contribute to fitness. As such they could easily be inactivated and that is what has apparently happened and that is why we do not see evolution of novel species and that is why evolution is no longer in progress and that explains loads of "junk DNA" and that is GUToB.
peebee
[ 30. May 2006, 11:17: Message edited by: peter borger ]
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peter borger
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posted 30. May 2006 11:39
quote:
You peak my interest when you speak of a continuum.
The continuum Zachriel speaks of is the falsified Darwinian hypothesis of common descent. The hypothesis claims there are NO real species, but only transitional intermediates. All living organisms are not real species, but on the move to become other species. The classic panta rei principle. However, the illuion of common descent is generated through the multipurpose genome (MPG), a genome that is in a constant state of flux, contineously adjusting gene expression patterns in progeny through jumping genteic elements. This generates the variabilty within the MPG and leaves an impression of organisms slowly evolving into other organisms. This observation made Darwin believe all organism were descended from one single primordial unicellular organism. But his vision, and that of the Darwinians is plain wrong. This has been proven now beyond any reasonable doubt in the search for the socalled last universal common ancestor. If it ever lived at all:
quote:
The wealth of new biology data has found that if a single LUCA really were the common ancestor to all current live forms, it must have had genetic information in more than one version.
According to some evolutionary biologists, the implications for LUCA are strange indeed. If a single LUCA laid the foundations for the modern diversity in membranes, metabolism and so on, it must have had several different versions of many important genes, in addition to the universal sixty. Later lineages would each have pruned all but one from this set, giving rise to the current diversity in basic biochemical pathways. The idea that organisms become more complex rather than less as you get closer to the root of the tree of life is impossible to swallow. [A single LUCA] would have had the most bizarre biochemistry imaginable, says David Saul of the University of Auckland in Nature magazine [22].
LUCA cannot have evolved by a Darwinian mechanism. More than one version of the same important genes means that LUCA’s genome was chock ful of genetic redundancies lacking selective constraints to be maintained. The obvious conclusion is that there has never existed a common ancestor to all life forms. LUCA is an illusion, an idée fix created by the dogma of common descent. Some scientists have begun to realise that the idea of common descent from a single universal ancestor should be abandoned:
The naïve picture that a group of organism got all their genes from a simple last common ancestor is breaking down”, says microbiologist Gary Olsen of the University of Illinois in Nature. In the past two years, it feels like it´s all fallen together into a coherent picture [that LUCA may have been a last common global community] [22].
Biology is very clear about it – Darwin’s hypothesis of common descent is false. (FROM: Borger's GUToB, p122)
Darwin was wrong, an so are his contemporary disciples. The funny thing is, they don't see it.
Why I wonder?
peebee
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