Posted on 02/11/2005 9:29:29 PM PST by restornu
Excellent stuff. Thank you. I thought that Spetner's contention that biologists haven't studied required rates of genome development to account for the fossil record and modern diversity seemed unlikely. Does Spetner address any of this work? (I am guessing that the answer is, "no", but probably that is because I am subtly reverting to my usual contempt for creationist work).
The problem is, that again and again creationists on these forums characterize evolution as entirely random; and when you ask them to explain ToE they dismally and signally fail to do so (they often either refuse, or explain a 747 in a junkyard parody of ToE, or start talking about cosmology etc (where the YEC are utterly deluded of course)). I have asked creationists to state ToE numerous times in these forums and only on 1 single occasion have I had a correct answer. I cannot think that Spetner is unaware of this yet he panders to this mischaracterization.
I don't know where you are headed, but this is from Futuyma's newest edition (note I cannot find the language you quoted above from the old edition in the new one).
"Environmental factors may affect the rate of mutation, but they do not preferentially direct the production of mutations that would be favorable in organism's specific environment" p.26, 3rd edition.
Does this help you?
There are instances where the rate of mutation appears to vary with environmental stress. There may be bacteria that have directed adaptations to specific stresses. There is no reason in principle why there couldn't be adaptive programs that only affect the genome. I don't think this line of research has turned up much. Mutation appears to be mostly stochastic, but it's of research results, not an article of faith.
Does this help you?
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Yes. Thank you. That confirms my understanding.
I've tried to read this stuff carefully with a layman's insight and the non-directed nature of mutation is a very key point. That's why I was surprised and followed up when I was told I was wrong about it.
I'll pass. I hope he does better with this than he did with his proof that Archioptrix was a fraudulant demonstration.
From what I can tell of this argument, it is the complexity argument applied to the micro/macro song. It took me years to force my way through Behe's and Dempski's technically steeped books, and I'm not about to subject myself to that again, for a physicist who gets published by Judaica press, and has already demonstrated some of the clear signs of being a serious science crank, until some noticable fraction of the biological community touts him.
Here are the two most obvious reasons I don't consider this a serious enough argument to read the book:
The micro-macro chasm is being pushed here, on The argument that random variations cannot produce "new" genes because information theory sez mutation can only be "decay" of information. This is oft-retreaded shallow poppycock that depends for what little pursuasive force it has on the irrelevent theory that the current environment is "perfect" for any set of genes. There are lots of observed counterexamples: Did you know that Haemoglobin predated creatures with bloodflow? Just to knock down one of Behe's feature players in this argument. Did you know that there is an entire chromosome's worth of genes difference between us and our nearest relative? Mutation takes place along many parameters, few of which we probably presently know about. This is just another, harder-to-discern argument that "because my giant brain can't imagine how something could have happened, it must be a miracle.". And I am, frankly, opposed to spending any more human energy on the arrogant claim than has already been spent on Dempski's and Behe's long-winded, time-consuming versions of it.
the author claims there is "no evidence" in support of macro-evolution. Now, he might have reasons for rejecting the available evidence. But claiming that it doesn't exist pretty much puts him outside the realm of serious consideration. There is far more abundant and profound evidence in support of evolutionary theory than of any other major theory in the natural sciences, and the creationist argument for dismissing all this evidence: that it is a record of the past, is completely bogus--all evidence is, practically by definition, a record of the past.
It might help you to vett these arguments if you realize that random distributions come in flavors. UNIFORMLY random genetic variation (which we probably don't have, but I'll grant you for argument's sake) Produces what statisticians call a uniform distribution (which is what I suspect you are erroneously picturing when you say random about genetic issues): any possible variation is just as likely as any other. After some winnowing function is applied to the resulting population, the distribution is no longer uniform. The selection pressure will shape the resulting population so that it is no longer uniformly distributed: if the pressure was of a uniform, linear nature, the result will be shaped curve, usually called a bell curve by statisticians, and a gaussian distribution by more serious math honks. If, then, the environment gradually changes in some direction--what do you think that will do to the creatures in the environment?
So...the unsuprising upshot of this is that environmental pressure shapes the creatures in the environment in directions favorable to surviving that environment, without any necessity to envoke an intelligent designer.
Uh, that's not what I said. I said that it is not "essential to Darwinism" that mutations are non-directed (i.e. random wrt to adaptive effect).
These propositions -- not essential vs does assume -- are not equivalent. In fact I entirely agree that evolutionary theory does indeed "assume" mutations are random wrt adaptive effect, but it's the same as any other scientific assumption: It's a default presumption or a null hypothesis; it's assumed absent some persuasive evidence to the contrary and/or some plausible mechanism which would provide for the phenomena.
I apologize that I can't recall details or the outcomes, but I know there have been occasions when scientists have pointed to data suggesting or have proposed mechanisms to produce directed mutations, and the issues were addressed so far as I know in the normal mode of spirited scientific debate without any visible panic over the possible demise of Darwinism.
There seems to be plenty of data at the present time to indicate that the vast majority of mutations are non-directed. But if there are some special cases and some particular mechanisms out there that do sometimes produce directed mutations, well, then fine. It's no problem. Or rather it will doubtless be an interesting problem to investigate and resolve.
Fine. As I said, that's the default assumption. Exceptions are allowed. They always are in science, and especially in biology, being a science that deals with objects that are characterized by high levels of complexity and diversity. There are in biology (even leaving evolution entirely aside) very, very few generalizations or "rules of thumb" that don't have exceptions.
Even (what is arguably) the single most basic and foundational generalization in all of biology -- the cell theory, claiming that all biological organisms are cells or are composed of cells -- has exceptions, for instance organisms that don't contain cells walls so that multiple nuclei are dispersed in a single mass of cytoplasm.
Also please note that the "evolutionary synthesis" Futuyma refers to was constructed circa 1940. Are there any other sciences you would restrict to the dicta of their pre-WWII status?
But now a name just popped into my head which may or may not be correct. I want to say a prolific experimentalist named "Hall," publishing in major journals like Cell and The Journal of Molecular Biology and so on, had some results suggesting directed mutation. I also *think* this may have been around the early to mid 80's. After reading furball4paws quote from the latest Futuyma textbook in msg #123:
"Environmental factors may affect the rate of mutation, but they do not preferentially direct the production of mutations that would be favorable in organism's specific environment" p.26, 3rd edition.
I'm now *thinking* that *maybe* this was how the issue of Hall's (?) seemingly directed mutations in bacteria was eventually resolved: That is that some stress induced hyper-mutation mechanism kicked in, so the calculations saying that the mutations were too improbable to be random were wrong.
Warning: these are *very* hazy recollections.
This is the main problem with discussing science with those who are neophytes in science. There is almost always an exception, especially is biology. We have generalizations to help frame problems, but there are always outliers. It comes from trying to "force" order where there is only a semblance.
E.coli has what are called mutator genes. These genes produce a product that causes high levels of mutations to occur - say they facilitate mutations. But the mutations they "facilitate" are the same ones that occur naturally, just at higher frequencies. There are "hotspots" also in bacteria where high mutation frequencies occur, but again they don't do anything that doesn't happen naturally. I could dig up some references if you want them.
There are also quite different frequencies for mutation between genes. Some mutate at high frequencies (as high as 10^-4) and some are quite resistant and mutate only at lower frequencies (as low as 10^-9). Because of all this mixing together, it would be quite difficult to prove some direction in mutation.
Having said that, I have left out transposons (the infamous "jumping genes") since they are another complicating factor. Their mutation sites are known, but I can't see much predictability in this area. Perhaps there's a molecular biologist out there that can clear this stuff up?
Warning: these are *very* hazy recollections.
I didn't realise that he claimed that. I'd got the mistaken impression from reading reviews of his work that he accepts macro-evolution and that he is arguing about mechanisms. If he truly does claim that there is no evidence for it then he is either ignorant of the mountains of evidence (which is unforgivable in someone writing a scholarly book proposing a theory to account for biological diversity) or for religious reasons he manages to pretend to himself that it doesn't exist. Does he not address the fossil record at all?
What a relief. They make our fruitloops seem quite sane by comparison.
Francis Hitching The Neck of the Giraffe. As I recall this one pretends to be merely anti-Darwin, not antievolution per se, but it then ends up making a number of typical "creation science" type arguments. It's among the more frequently cited by "mainstream" creationists. Hitchings (sp?) has also writen on "ley lines" and other new age stuff.
William Fix The Bone Peddlers. Many typical creation science type arguments concentrating of human evolution. I don't recall exactly what Fix believes, but it was something stupid like aliens did it, or the gods or some such.
Algeny and other works by Jeremy Rifkin. Famous lefty luddite. Nuff said.
On the Hare Krishna, here's something from floppy I found in the attic, something I wrote for a BBS echo in 1991, in the dark days before the internet:
Hindus -- Don't know about "mainstream" or "traditional" Hinduism (or even what the appropriate terms are here) but do know that the founder of the International Society For Krishna Consciousnes rejected evolutionary theory. Although "scientific evidence" is offered in the manner of our own "creation scientists" the real reasons are likewise religious. As explained in _Life Comes From Life: Morning walks with His Divine Grace A. C. Bhaktivedanta Swami Prabhupada_ (The Bhaktivedanta Book Trust, 1979) biological evolution contadicts reincarnation as taught by the Bhagavad-gita and the Vedas. Reincarnation teaches that the soul "evolves" but the "species" it inhabits are constant and unchanging. The Swami engages in some classic scientist bashing and anyone with an anti-evolution library ought to pick up a copy of the book next time they go to the airport. A. C. not only says that scientists "are not nice men" but even "that they are not human beings" (p.14)!!! Well, that last quotation may be just *slightly* out of context...BTW, did you know that the Vedas number the "species of life" at 8,400,000? This is actually right in the probable range of the total number of extant species (somewhere between 5 and 10+ million). Hmm...
AFAICR they are much closer to the scientific age of the universe too, than most religions. Doubleplus hmmmmm.
'Course I could never go along with the reincarnation bit, and the orange robes are a deal killer in themselves.
Remarkably Spetner does not straightforward deny macro-evolution, he claims that neo-Darwinism (accumulation of small changes) cannot account for macro-evolution. This would imply macro-evolution exists. What is clear (is) that he denies that macro-evolution is an extension of micro-evolution. Further he claims that NREH is a better explanation for micro-evolution. Spetner accepts that micro-evolution occurred. He disagrees about its causes
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Korthof's explanation from here...
http://home.wxs.nl/~gkorthof/kortho36.htm#Par3
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