I am reading a debate between Young-Earth Creationist Duane Gish and Evolutionist Ken Saladin. Gish has a Ph.D. in biochemestry from UC Berkeley and Saladin has a Ph.D. in parasitology from Flordia State.
Early in Saladin's opening comments he states:
"...science is empirical. That means it's based entirely on things that can be observed. Science is not based on revealed truth or idle speculation."
The first link in his chain of evidence for Evolution is the well-know story of the peppered moth:
"In any college biology textbook you can read the story of the peppered moth, which made a visible evolutionary change in a few decades under the influence of pollution and predators. That's what evolution is: the ability of a population to adjust genetically to environmental changes."
I assume Saladin relates the peppered moth story simply because it is well-known. However, I was surprised that he gives the peppered moth such a high profile (Exhibit #1, one minute into a 45 minute introduction). Why?
1) Because the peppered moth experiments Bernard Kettlewell conducted in the 1950s have been shown (by devout Darwinists) to have serious methodological flaws.
2) The experiments have no relevance to the controversial Darwinian claim of explaining how species originate.
3) In order to extrapolate proof of Darwinism from what valid evidence we can gather from the peppered moth (if there is any) requires a truckload of the very speculation Saladin labels anti-empirical and anti-scientific.
Now Saladin gets a pass on the first point. The peppered moth story was not widely debunked until the late 1990s; the debate in question occurred in 1988. However, I highlight the debunking since the peppered moth story is still widely purported to be clear evidence for—if not proof of—Darwinian macroevolution.
This brings me to my second point. Even if we overlook the problems with Kettlewell's experiment, what does it teach us about evolution? As the moth's environment changed from lighter lichen-covered trees to darker soot covered, lichen-free trees, the darker moths became a greater percentage of the general peppered moth population, probably because the lighter moths fell prey more easily to birds. From this we are supposed to be convinced that all the diversity of life on earth could spring forth from one primitive form. But this story sheds no light on the origin of either the light or the dark moths. From the industrial revolution to the mid-20th century the darker moths survived in greater numbers, but the members of the species experienced no evolutionary change whatsoever. Genetically, they exited the period of evolution exactly as they had entered it. After Clean Air laws passed, the environment reverted back to favor the lighter moths, and, as a result, their percentages increased. The peppered moth story may serve as an example of how a species may go extinct, but what does it tell us about how species arise, which is what Darwinism is purported to do?
So how did the fabled Peppered Moth become Exhibit #1 in the case for Darwinism? By way of that noxious mixture of revealed truth and idle speculation. In this case the "revealed truth" is that God does not exist, therefore, life must have evolved from non-living matter by purely naturalistic means. The idle speculation is that any variation within a population brought on by environmental conditions is evidence that large scale genetic changes are also possible in the same way—despite the fact that the empirical evidence gathered throughout human history shows that such variation has narrowly defined limits even when guided by intelligent minds under ideal conditions.
So why does Ken Saladin give such prominence to such flimsy evidence? Could it be that's all he has? I have little expectation that better evidence is forthcoming.
5 comments:
AFAIK the moth thing is a classic example of adaptation to changing environments rather than evolution or even speciation. Although it is easy to imagine how the white and black moths could have become different species over time if they where basically isolated in their particular environments for long enough.
AFAIK the moth thing is a classic example of adaptation to changing environments rather than evolution or even speciation.
Kettlewell called what he observed “the most striking evolutionary change ever witnessed by man” (Kettlewell 48).
Sadly for Darwinists this remains true, which is why Saladin referred to it. The problem is that the moths didn't undergo any biological change whatsoever, there were just more or less of the two varieties over time.
Here are some other published examples of how the peppered moth is presented:
The peppered moth story is “the single best-known evolution watch in history” (Weiner 271).
“The peppered moth, Biston betularia, is rightly regarded as a striking example of adaptive change through natural selection and as one of the foundation stones for the modern synthesis of evolutionary theory” (Brakefield 376).
“Typical [light], intermediate and melanic [dark] forms of the Peppered moth Biston betularia . . . furnish one of the best known examples of evolution taking place before our eyes” (Blaney 137).
“Organisms can adapt to moderate amounts of certain forms of pollution: the spread of industrial melanism [darkening] in peppered moths and other insects, and of heavy metal tolerance . . . in certain plants, have provided some of the most convincing evidence for evolution by natural selection” (Skelton 954).
Although it is easy to imagine how the white and black moths could have become different species over time if they where basically isolated in their particular environments for long enough.
Sure, it can be imagined easily enough. Proponents of evolution imagine for page after page and then call it undeniable evidence. What I'd like to see is something other than stories made up to fit observed facts to the hypothesis. Macroevolution has never been observed, and what we can observe of adaption—both guided (by man) and unguided (by natural selection)—indicates that it's not possible. Yet I'm supposed to believe that given lots and lots of time the impossibility is somehow overcome. This is Darwin of the Gaps.
LB said: Macroevolution has never been observed, and what we can observe of adaption—both guided (by man) and unguided (by natural selection)—indicates that it's not possible.
By 'macroevolution', do you mean the emergence of new species?
If it could be shown that it does indeed happen would you amend your attitude to evolution? Can I presume from your comments that you do not accept it? If so, Why?
Actually I do struggle with why some people at least find the idea of evolution to be controversal in any way. To me, admitedly a non-biologist, it seems pretty straight forward and makes perfect sense. It has been many years since I studied it in school (back in 1978-79) and I haven't read much about it since. I do however have a few books on that subject lined up to read next year and in fact I'll be reveiwing one on Thursday - though it doesn't cover speciation.
Microevolution: Evolution resulting from a succession of relatively small genetic variations that often cause the formation of new subspecies.
Macroevolution: Large-scale evolution occurring over geologic time that results in the formation of new taxonomic groups.
I cribbed these definitions, but I did so in order to be precise. The peppered moths, like the Galapagos finches, exhibited microevolution in that they remained moths and finches, even if the varieties are considered different species. An example of macroevolution is a fish becoming an amphibian, then a land mammal, then a whale. Of course I don't require that this complete process be observed in order to be validated, but I also won't accept it on faith simply because it can't be observed, given what we know from what we can observe.
To me, admitedly a non-biologist, it seems pretty straight forward and makes perfect sense.
I agree that, in some cases, it makes sense. For example, when I hear some nature show narrator tell me that human females developed wide hips via natural selection as males chose them for their perceived reproductive advantages, I can see that this makes perfect sense in a post hoc sort of way, but I don't see where any science is being practiced, just storytelling.
What makes me actively doubt macroevolution, and Darwinism/neo-Darwinism in general, is a combination of factors, namely random mutation, gradualism, and survivability. Then are are the incalculably long odds against the strings of seemingly goal oriented mutations the theory requires. Then there are lots of other things.
I will freely admit that my skepticism of Darwinian Theory is rooted in my semi-fundamentalist Christian upbringing. However, I have discarded more than a few notions I was taught in church as a child. My continued dismissal of Darwinism is not now related directly to my religious beliefs, but to my understanding of how things work. Many Christians accept Darwinism. Many non-Christians reject it. So, as a Christian, I have intellectual cover to take any of a variety of positions on the origins and diversity of life.
I look forward to reading your book review.
LB said: I look forward to reading your book review.
I posted it on Thursday 22nd. It doesn't directly address any of the issues you raised but might still be of interest to you.
My passions (book wise) at the moment are history and politics (I'm considering doing a degree in it next year) as well as my continuing interest in all things philosophical. I'm attempting to fit in a few science texts too and I'll let you know if I come across anything that you might like to read.
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