Posted on 01/26/2006 11:47:13 AM PST by PatrickHenry
Environmental stress isn't the only factor in natural selection. Sexual selection is well-recognized. Environmental stress is one of the causes of mutation, but not the only cause.
And the great hypocrisy of promoting environmental stasis in the name of maximizing the gene pool and species diversity.
Because, like *all* inheritable mutations, they first occurred *in* reproductive cells. This is such basic biology that the article didn't bother to spell it out -- it would be like an article on a new airplane design not bothering to mention that aircraft need an atmosphere to fly and don't work in a vacuum.
Nothing in the article suggests the strange scenario you described, involving all the cells in a body mutating simultaneously. That such mutations must take place in germ cell lines is a "given".
If I am missing something, please, explain it to me.
See above.
P.S. Unlike you, I have never read creationist literature.
Then it's odd that your argument is a direct repetition of one of their standard canards. If you haven't read creationist sources, you've picked up their arguments indirectly.
This is pure logical analysis and evolution has never added up in my book.
If it were "pure logical analysis", it would not contain such elementary fallacies. For a description of how new mutations enter the population and eventually lead to speciation without there ever being a point where an individual has a problem mating with the members of the population to which he/she belongs, see this.
You might also try this. Not as authoritative as Ichneumon, but it's readable.
How can you claim to have anything of value to add to these discussions if, after all this time, you're *still* unclear on the distinction between the fact of evolution and the theories about how it proceeds in specific instances?
Hint: Evolution is slow in some instances, not so slow in others, depending on the circumstances. This article addresses some particular types of circumstances which affect the tempo and mode of evolutionary change. There's no contradiction with prior research.
This article is nothing more than wild speculation
It's based on a great deal of work, which puts it far beyond "wild speculation". It may or may not turn out to hold water when further investigated, but your desperate creationist habit of trying to hand-wave away all research and considered conclusions based on a thorough examination of the real-world evidence as "nothing more than wild speculation" just makes you guys look goofy. Sorry, but "wild speculation" is what *creationists* do when they make up things based on their total ignorance of actual biology and then mistake their presumptions for established facts. For example, like *you* did here when you made wildly incorrect assumptions about how biology "must" work... Now *that* was "wild speculation"!
presented in an attempt to overcome the obvious weaknesses of the many theories of evolution speculated about by others.
And what exactly would those "obvious weaknesses" be? Be specific, let's see if you have any clue what you're talking about. Be sure not to repeat any of these other long debunked creationist canards about the "weaknesses" in evolutionary biology.
If anything, this article casts further doubt on evolution.
It doesn't, but your post casts further doubt on your ability to keep up with technical discussions.
I like the idea of mutations remaining recessive over time until drift makes them co-recessive at which point the trait gets expressed; but I don't think a saltation event even in this scenario would be likely to have a high survival index. I suspect this is more like what happens with segmentation where a simple mutation on a HOX gene can confuse enzyme production resulting in multiple segments. Or multiple wings for that matter.
Interesting when viewed together with gene duplication followed by a partial-gene mutation on the regulatory gene.
BTW, my mind is a toaster right now, so don't blame me if'n I'm incoherent.
True, but randomly occuring mutations (random with respect to the selection function) will yield a system that moves with jumps of all sizes.
There is also the genotype-phenotype relationship. It may take several small changes in genotype to make any change at all in phenotype. Likewise, some small genotypical changes may result in large phenotypical change.
I think that "random" here would be shorthand for "mutation not necessarily related to selection."
Dear Lady, don't get the idea this concept is saying a large scale saltational event is occurring, it is more like a slow 'partially or totally hidden' bit of evolution occurring before its relatively sudden expression.
If this mechanism, or process if you prefer, is the active process in a population... oh, evolving legs let's say, the legs would not end up being full blown legs like yours or mine, but simply a larger scale 'change' to existing features, such as fins, than we would normally expect, or it could result in 'leg buds' where an existing skeletal feature is replicated in another place or modified in place - such as an additional segment of bone is added. For true legs to result from these 'buds' it would still take hundreds of generations. Remember what geological time really means.
Neither do farmers.
Don't ask me, I don't know...
2x2=4 4x4=8 8x8=16 16x16=....
Well I only 'stinct' a little.
Interesting point here. It is environmental stress which interferes with the genetic "proofreading" mechanism and allows the effective mutation rate to climb in times of deep crisis.
The more I think about this, the less impressed I am by the randomness of mutations. It seems that mutations are very common. I've read that each human conceived may have 100 mutations (of various types, most irrelevant). Given that kind of genetic background, we could almost consider mutations as a given, much as we assume that the origin of life is a given. By that I mean that it almost doesn't matter where life (or mutations) come from. They're here! That said, natural selection is the whole game. And that's not random. But I suppose mine is a fringe view. No big deal.
Is there some new definition of speculation for which I am unaware?
Did you have a relevant comment, or are you just reduced to non sequitur questions?
True, but for several reasons mutations of large "size" (i.e., a large effect on the phenotype) will be far more likely to be harmful (as well as immediately fatal) than small changes.
In fact, for a continuous fitness function it can be shown mathematically that as the size of the change approaches zero (i.e., for smaller and smaller changes), the odds of a mutation being beneficial (albeit to a correspondingly small degree) approach 50%.
Dawkins discusses this point in a few of his books (including "The Blind Watchmaker" and "The Ancestor's Tale"), giving credit to statistician and biologist R. A. Fisher for having made the point originally. A direct consequence of this observation is that evolution is far more likely to proceed via accumulated small changes than by mutational "leaps" of larger effect.
Would all of the particular species acquire legs? What if a particular species were separated by great distances? If they were in close proximity to one another, would genetic drift affect all of them at the same time?
They say that when something seems laughable or nonsense it might indicate a misunderstanding.
Agreed. Sudden Origins does not contradict Intelligent Design it works Hand in Hand with it.
Gradual or rapid, depending upon the nature and severity of the enivronmental pressure, it's still solidly evolution.
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