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The Evolution of Flying Squirrels
| November 20, 2007 | Posted by William Dembski under Just For Fun |
I never quite believed in the evolution of flying squirrels from regular squirrels (i.e., by increasing skin folds that allowed for better and better gliding) until I watched this video:
43 Responses to The Evolution of Flying Squirrels
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Jehu,
There are actually several recent studies in the area of experimental evolution, looking at “first steps in adaptive walks”. These studies generally look at fitness advantages of mutations in bacteriophage. They have found that in some experiments multiple mutations with fitness advantages will arise during the course of the study but generally only one will fix. Many of these are equally advantageous. I think this may get at your question.
jdd,
All beneficial mutation studies are suspect.
Usually, In order to get the a “beneficial” mutation to fix, the environment must be manipulated in order to put “stress” on the bacteria to “evolve”. Yet, time after time, when the normal “living” environment is reestablished the original bacteria will out-compete the “evolved” bacteria. In fact the further a bacteria is “evolved” away from the original bacteria the more quickly it is out competed by the original. In fact, the super-bacteria in hospitals that have acquired multiple resistance to multiple antibiotics are commonly known to be super-wimpy when forced to compete with the original bacteria.
The main point to this being, is that beneficial mutations, if they even exist at all, which I believe they don’t, always turn out to decrease fitness when forced to compete in the wild with original bacteria.
As well jdd
http://mbe.oxfordjournals.org/...../19/9/1637
of special note:
“Almost without exception, bacteria isolated from ancient material have proven to closely resemble modern bacteria at both morphological and molecular levels.” Heather Maughan*, C. William Birky Jr., Wayne L. Nicholson, William D. Rosenzweig§ and Russell H. Vreeland ; (The Paradox of the “Ancient” Bacterium Which Contains “Modern” Protein-Coding Genes)
jdd, as such, the belief in beneficial mutations, in living organisms, actually seems to be based on blind faith in Darwinism than any actual concrete evidence that can withstand scrutiny.
Jehu, “How do you prove that a trait not getting selected is a slight advantage?”
A good question, an inquisitive question. A genuinely scientific question.
I have been brainstorming “how do you prove” for the last day or so. I wonder what would happen if you studied the DNA of the flying squirrel, and of its nearest non-flying cousin. Could you find a single mutation event (point mutation, duplication etc.) that produces some amount of webbing between the front and back limbs. If you can’t, this would not bode well for NDE. If you can, then you should be able to experiment.
If you induce this mutation into a non-flyer, he should have some webbing between his limbs. If you then take an area of flying squirrel habitat, say a square mile, and isolate it from all squirrels (that might be a challenge) then place a bunch of regular squirrels, and a bunch of “flying mutants” into the forest and watch them grow. If NDE is right, the flying mutants should begin to dominate the forest. If they don’t it would be difficult to claim that exactly that happened in nature.
I know this would be a big experiment, however I am of the mind that the NDE perspective is presented as fact with very little controlled experimentation to support it. Alas, if NDE really wants to be recognized as fact, the scientific community must solve the riddle of first life, and must experimentally prove that more difficult developmental phenomenon, such as the bacterial flagellum, are possible via chance + necessity. Those will be much harder to do than proving the evolvability of the flying squirrel.
Folks,
I’ve posted several replies, but they continue to be “awaiting moderation.” I assume this is a glitch in the system, nothing I can do about it.
BA77,
A couple of things. First, I was talking about bacteriophage, not bacteria but that is a small note. Second, in the studies I was talking about, the phage were not placed in a “harsh” environment, they were adapted to a new host. The phage could have sat there unchanging forever waiting for an e-coli to happen by and not died, instead there happen to be several mutations which allowed them to infect a strep bacteria.
Third, adaptations always refer to the current environment not the ancestral environment. It is true that these adapted phage would probably not due as well on e.coli being adapted to a new host but that is not the point. What was found is that there were several paths which increased fitness on the new host but only one fixed in the end. When the different mutant forms were isolated they all had the same fitness, within measurement error.
Fourth, I read the article you posted and I don’t see how it is relevant to your point.
jdd,
The article is very relevant (in fact the evidence in the article is a crucial key) to the whole beneficial mutation debate, because it points to a consistent fact, That fact being that ancient bacteria consistently do not “evolve” as is required by the “molecular clock” of the Darwinian scenario.
Evolution is absolutely required to have a certain amount of change in bacteria over 250 million years. Yet all change to bacteria is negligible and in fact has been argued to be within the “diversity range” of modern bacteria and thus “just” a modern contaminant(I argue that the slight change just may in fact be due to Genetic Entropy). I find it very interesting that Darwinists require a certain amount of change to DNA even though the morphology was/is expected to remain the same in the bacteria.
Yet what is found time after time when the bacteria are tested…NO SIGNIFICANT CHANGE!!
If you read the paper, then you see how they try to go through all sorts of contortions trying to get the evidence to fit a evolutionary scenario. (And fail)
But the fact remains that the evidence fits the ID/Genetic Entropy mo^del to a tee and could very well falsify the evolutionary hypothesis is the evidence is pressed by ID advocates to its fullest.
The paradox is so overwhelming that , even though the test they preformed are rigorous and consistent with many fail safe checks, “they can’t believe what their eyes are seeing” and say the evidence just very well may be a modern contaminate. (Can’t doubt good ole’ Darwinian evolution can they?)
BA77,
the question from Jehu was “How do you prove that a trait not getting selected is a slight advantage?”. The experiments that I was talking about showed that several mutations arose and then tested the fitness of each mutation and found that several were advantageous but only one was “selected” that is fixed. This shows how you can show that a trait not being selected is advantageous.
The paper you posted shows that some bacteria that lives in a layer or rock thought to be 250MYA has a few genes that have not changed much since it diverged from it’s ancestor. I don’t see how this is at all relevant to the question that was asked.
jdd,
Overall in the big picture, Your papers are asserting that beneficial mutations do indeed happen and that they may become permanently fixed “if the environment changes permanently”. (They, a-priori, believe evolution is true in other words)
I hold that more information will never arise by natural processes once the bacteria have been designed, and that all adaptations away from original bacteria to new environments (although advantageously selected for) will always come at a cost of the highly integrated, poly-funtional and poly-constrained, information in the original bacteria (The paper I cited supports my position in dramatic fashion; no significant change in 250 million years though the environment has surely fluctuated). I point out, that my position is also consistently upheld with many other test (antibiotic resistance, nylon adaptation, heavy metal adaptation, etc..etc.. have all been analyzed and shown to always occur at a cost of information in the original bacteria) Whereas your position requires a “belief” that the environment change is permanent and that the mutation is truly beneficial through and through. I maintain that your test (papers) will be found to overlook complex symbiotic relationships that are in fact detrimentally affected when the “beneficial” mutation occurs.
You stated:
The paper you posted shows that some bacteria that lives in a layer or rock thought to be 250MYA has a few genes that have not changed much since it diverged from it’s ancestor.
jdd, you used the words SOME and FEW, this test IS NOT an anomaly, it is a consistent finding;
“Almost without exception, bacteria isolated from ancient material have proven to closely resemble modern bacteria at both morphological and molecular levels.” Heather Maughan*, C. William Birky Jr., Wayne L. Nicholson, William D. Rosenzweig§ and Russell H. Vreeland ; (The Paradox of the “Ancient” Bacterium Which Contains “Modern” Protein-Coding Genes)
The point being is that your paper is not rock solid conclusive proof for beneficial mutations being proven true, by a long shot, and should not be taken as such, as you are in fact doing.
jdd
I didn’t see where you posted a link to a paper. And I am curious to know how you determine the fitness of a mutation that does not get selected. Also, you are aware that bacteriophages are viruses and as such cannot reproduce on their own? Think about it.
Off Topic; Here is a song for everyone who is writing a book;
http://video.google.com/videop.....;plindex=0
Ordinary squirrels have been observed to fall from great heights with little or no injury.
Hu,
Interesting. So a little extra skin would provide even less of a selective advantage.
Considering the overlap of subject matter I ended up addressing flying squirrels here:
http://www.uncommondescent.com.....ent-150893