Evolution and complexity

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And selective pressure also causes stasis(ie,no change) and the more pressure also leads to more stasis.

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Sorry dwise1,this is a obvious nonsequitor.Yourthermos analogy does support stasis, but it cannot rightly be applied here as it is an example of insulation/isolation from selection pressure.
Indirectly it might be argued that more selctive pressure might lead to more stasis, if you include formation of more efficient immune systems or error checking/correcting mechanisms.
Thermal Mass and or Inertial Mass might be better analogies for stasis in this case.Given a large enough popolation(mass), selective pressures would either be dilluted or absorbed.(depending on which analogy you use)Edited by Simonsays, : No reason given.

Wrong dwise...It was right on. This is what one calls moving the goal posts!
Yes, a negative-feedback control loop can help to preserve stasis.The key words here are feedback and loop.You have neither in a closed system such as a thermos.
The selective pressureis not there, as far as I can see, in such an enviroment(closed system - thermos).
Also, the negative feedback example isn't general like the thermal insulation analogy. It's specific.It only works with specific selective pressures. And your'e still going to get selection and improvement of the negavtive feedback mechanism, or extinction if the proccess is taken to an extreme. Not more stasis.

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Oh! You're complaining about the thermos!

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No, What I'm objecting specifically to is your nonsequitor... And it still exists. I'd assumed your "thermos" analogywas the warrant for your argument,both because of its content,and because of its location.(right after your main assertion)
If your "thermos" analogy is not your warrant, then what is? You have basically reworded your proposition three times(although #3 does lead to an alternate conclusion);1.)

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But if a population is already well adapted to its enviroment then selection pressure will act to resist change and hence keep the population in stasis

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(ITALICS MINE)2.)

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But if the population is already on an "ideal" genome, then selective pressurewill cause it to stay there, thus resulting in stasis

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(ITALICS MINE)3.)

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Wheras specialized species that are finely tuned to their enviroments will have less genetic diversity and will most likely not be able to survive changes in their enviroments

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(ITALICS MINE)Also, your thought experiment seems to focus on population(species?) selection and gene selection(see Dawkin's "Selfish Gene") (i.e.,an ideal genome),not on Darwin's natural selection (selection at the individual organism level)
Given that it came from Gould's and Eldridge's (first ?) conference not unusual .But applicable? I don't know. Edited by Simonsays, : dB coding errors. Punctuation error.

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What non sequitur are you talking about? I had written none.

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No dwise1. What you haven't written is a warrant. You know ... What I asked you for in my last reply. Without a warrant to connect your proposition to your conclusion you do have a nonsequitor. Again I ask you to present one.(print out the words and/or sentences in your past message/s that constitute your warrant!)

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The thermos analogy is from an old joke where a dim-witted individual says it's the most wonderous invention because it keeps hot stuff hot and cold stuff cold, but how does it know the difference? The full extent of the analogy is that the same mechanism just operates the same in both cases; it doesn't need to know anything. The thermos does not need to know whether it contains hot liquid or cold liquid, because its mechanism of preventing the transfer of heat into or out of the thermos bottle has the seeming contradictory effect of keeping hot liquids hot and cold liquids cold ...

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This sounds like a statement a student of mine made years ago. although, he was just very young, not dim-witted. He commented on how unlucky it was that the tennis balls kept going into the puddles from the recent rain. I said that it wasn't luck. The balls are there for the same reason the water was. (Was it raining tennis balls ?) No, it's just gravity. They both stop at the nearest low points of the court.

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... Evolution doesn't need to know how well adapted a particular species is in order to regulate how rapidly it changes; the same mechanisms ... cause different rates of change in different circumstances.

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Very interesting... Now if you could list for me some of those same mechanisms which under selective pressure lead to stasis ,(ie; balance,equilibrium,or stoppage of flow.)(from the American Heritage Dictionary), instead of different rates of change, then you might actually have a warrant to support your assertion.

Does anyone here (besides me) no what a warrant is in a logical argument? If so, please type out (or copy and paste) the warrant in any of dwie1's replies that you think is applicable in this case:

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And selective pressure also causes stasis (ie,no change) and the more pressure also leads to more stasis.

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I think Percy thinks he has a warrant with his thermal equilibrium (potential energy) model. But I will show in my coming reply to him where I think he misses the mark.Edited by Simonsays, : Grammar and a dB coding error.Edited by Simonsays, : ommitted words.

Oh,ha,ha,ha. Lol.
I'm sorry, I thought this was a science forum. In science forums you are required to back up (support) assertions. Edited by Simonsays, : Changed "your" to "you are".

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A rate of change of 0 is stasis

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Yes, Dr Adequate that's technically true... just as no answer is technically an answer. Although I think most people would find no answer an unsatisfactory answer. As do I with my honest request for a warrant.
I can't see how increased selection pressure could ever lead to stasis (equilibrium). To me this is an example of a supposed effect without a cause. As the saying goes,"[i]sho' me the money."

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Some of us know that "know" is not spelled "no." That is a no-no.

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And some of us know what a typo is. Also, as I have mentioned in a past post:
1. I'm under time pressure:
a.)Home computer: periodically drops into power save mode losing text,when it works at all. (safe mode)
b.)Library Comp.: limited to 1 hr., minus the time checking and replying to my tennis lesson and personal e-mails.2.) I'm an extremely slow typer.(pick peck)
3.) I haven't done much posting and am new to coding (dB/HTML)
4.) I Don't always have time to spell checkFor the above reasons you should not be surprised if I occasionally have a typo or punctuation problem.

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Some of us also understand the difference between "Truth-preservation" models and "warrant-preservation" models.

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A few of us even followed the Intutionists over the years which is also totally irrelevant to anything in this topic.

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There are, I'm sure, a lot of things I do not know. Just as there are a lot of things I do know. I never claimed to be all knowing. I will however look up these terms, time permitting. I'm not adverse to learning new things.

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Some of us even know that you are just shovelin' shit and are clueless of the topic.

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Have you ever heard of the term unwarranted conclusion ? (ie,a not warranted conclusion,a conclusion with no warrant to support it). If not, see the above quote...It's a good example of one. You have no idea what I do or do not know, have or have not read. I've noticed that True Christians/Creationists seem to have this uncanny ability to just know things.(unfettered by fact and with little or no evidence).
Unquestioned Truth is not truth at all... It's merely dogma.Edited by Simonsays, : dB code error.Edited by Simonsays, : No reason given.

Percy,
Obviously I believe they are not correct, at least not in
the the highly generalized way they are being applied. So what I'm really arguing is semantics, I guess.
If the mechanism is supposed to be a general negative feedback cycle I can't picture/model that in my mind.
If it is a special case (ie, one selective presssure affecting a single trait/character) then no problem... I think that you guys have clearly shown that that will lead to a stopping and not just a slowing down of change.
I will address those other examples tomorrow hopefully, in replies to the posters who posted those analogies. Pesto and Nosyned,I believe.
As to your improved Thermal analogy; I think you left off the selective pressure part, if it's meant to apply to the general case i'm objecting to.
Continuing your analogy and using thermal energy as the selective pressue:I think I can improve upon the thermos analogy by substituting a temperature gradient, meaning things are at different temperatures. The laws of thermodynamics want to smooth out a temperature gradient so that everything is at the same temperature. Heat flows toward cold.So when a cup of coffee is at the same temperature as the air, then there is no heat flow. The cup of coffee doesn't have to know that it's the same temperature as the air, that's just the way heat flow works. This is analogous to a population that is well adapted to its environment.And when a cup of coffee is much hotter than the surrounding air, then there is a net heat flow from the coffee to the air. This is analogous to a population that is not well adapted to its environment. The flow of heat is analogous to change in allele frequencies in the population.--Percy
And I take this coffee and pop it in the microwave... Turn it on high.
Now The coffee and the surrounding air differentially absorb this microwave energy. That is the selectivepressure. Now, since they are at different temperatures, heat begins to flow again.Then changes in allele frequency happen again to the population(they continue to evolve)( Result-no stasis)Edited by Simonsays, : Word changes.Edited by Simonsays, : Punctuation errors, and typos. Added the word "Negative" and changed "keeping" to "using".Edited by Simonsays, : wording; flows-flow.

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Simonsays writes:
I think you left off the selective pressure part...

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When I wrote... the selective pressure ... , I did not mean The with a capitol "T". As in one and only one selective pressure. I meant it to represent the more pressure (ie, more selective pressure) as in dwise1's quote.Here again is dwise1's quote that I took exception with:

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And selective pressure also causes stasis (ie, no change) and the more pressure also leads to more stasis

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selection[/i] in his quote. However, I believe it was implied when he said

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...when the mutations are there...

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Likewise, I think dwise1 did the same thing with his adaptation analogies.

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No, it's in there, but let's look at your own analogy first.

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It as in one ? I think that's a special/unrealistic case.

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Is the microwave off now?

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Sure. Microwave ovens have timers... They don't run forever.

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...Because if the microwave is the ultimate source of selection pressure...

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I never said it was the ultimate/only source.

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...then turning it off removes the selection pressure...

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How so ? Your heat flow and my Microwave input are equivalent. They're both energy flows.

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...why do you mention heat flow in connection with changes in allele frequency?...

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Because you do. You compare (say it's analogous) to changes in allele frequency of a population.

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... is it microwaves or heat flow?...

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What's the difference here?

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Simonsays writes:
I think you left off the selective pressure part...

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Percy, I qualified my statement. You left this part out of your quote:

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..., if it's meant to apply to the general case i'm objecting to...

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I'm used to seeing selective quoting like this from Creationists, not evolutionists... I trust it was unintentional.Edited by Simonsays, : Words were ommitted when I submitted my reply.

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Does anyone here (besides me) know what a warrant is in a logical argument?

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Yes, Jar, I corrected the Know-no typo. Don't worry, I left the original quote unedited so that your response still makes (sense?).I also changed my qualifying terms into italics.You seem to have ignored my qualifiers.(Try adding them to a google search for an accurate definition of warrant,in regards to my usage).I presume you are familiar with boolean logic, and that should be no problem for you.Btw a warrant as used in a "warrant-preservation" model is not the same as a warrant as used in a logical argument.

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Some of us even know that you are just shovelin' shit and are clueless of the topic.

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If by topic you are refering to the term warrant as it applies to a logical argument then no I am by no means clueless of the topic!
If by topic you are refering to all the various usages of the term warrant,then again I'm not clueless.I may not know all of them, but I have no difficulty deriving a meaning, if sufficient context is provided.(In your vernacular, I would say) "Shit man I'm no SimpleSimon". My interests include; reading(including A-Word A- Day), chess, and solving cyphers (Cyberquotes-in the Sac.Bee newspaper)(I also do the scrabblegrams,crosswords,scrabble,boggle,etc.).

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A few of us even followed the Intutionists over the years which is also totally irrelevant to anything in this topic.

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Intutionist ? Pretty arcane term there. And one that I agree is totally irrevelant in this topic.

Simonsays writes:
I think Percy thinks he has a warrant...

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You're using the word "warrant" in a way no one here is familiar with. Here's the definition of warrant from Answers.com:

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war·rant n.1. Authorization or certification; sanction, as given by a superior.2. Justification for an action or a belief; grounds: “He almost gives his failings as a warrant for his greatness” (Garry Wills).3. Something that provides assurance or confirmation; a guarantee or proof: a warrant of authenticity; a warrant for success.4. An order that serves as authorization, especially:a. A voucher authorizing payment or receipt of money.b. Law. A judicial writ authorizing an officer to make a search, seizure, or arrest or to execute a judgment.5. a. A warrant officer.b. A certificate of appointment given to a warrant officer.{QUOTEWhich of these definitions are you using?[/QUOTE]None. Although #2 and/or #3 come close. (ie, Justification for a belief, and something that provides assurance or confirmation.You can find a more accurate definition (what definition I'm using) by including in your search terms the qualifiers (logical, and argument) that I used.(as I suggested to Jar)(ie, warrant + logical + argument)

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The thermal equilibrium example of a cup of coffee and its surroundings was intended as an explanatory analogy (not a "warrant") to evolutionary stasis, where a population is in equilibrium with its environment. If you don't find the analogy helpful then we'll continue seeking an explanation that works for you.

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Percy, I'd settle for an explanation that works. I don't need more examples of Stasis and negative-feedback systems.I understand those, and can list off a bunch of examples myself, as I suppose most of you can. For example, in physics, a standing wave is an example of stasis(with phase and frequency being the controlling inputs).What I would like is a mechanism and a justification that it can be applied in the specified (general) case. Barring that I would except dwise1 adding the qualifier (may or can)lead to stasis to his assertion, since he admitted he can't identify his generalized negative -feedback system. Edited by Simonsays, : . Punctuation.

An example of stasis
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If an animal is prey to a fast predator then any change that reduces the prey's speed is under intense selective pressure and those changes can not spread in the population.

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can not ? I don't think so. If the reduced speed is compensated by some other survival trait/tactic I don't see any reason why those changes couldn't spread.

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If the prey animal lives in a warmer climate that is starting to cool then increased body fat would be another answer to the new selective pressure of the new environment. However, this would slow the prey down and the predator selective pressure will maintain the body form of the prey.

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And the predator would also be subject to this new selective pressure, now wouldn't it ? Granted there are other ways to cope with cooler temperatures; fur(hair+air) and feathers come readily to mind.So the form could change as long as the selective pressures balanced out.Edited by Simonsays, : Deleted "it".Added quotes.

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Unquestioned TRUTH is not truth at all... It's DOGMA. Seek and ye shall find !

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I can't see how increased selection pressure could ever lead to stasis (equilibrium). To me this is an example of a supposed effect without a cause. As the saying goes,"sho' me the money

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I'm sorry Pesto, I forgot to qualify this statement.(I was/am a bit frustrated with the type of replies I was/am seeing here). I was again refering to the general case dwise1 was using...not the limited case(one selective pressure)you are using.

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Let me give you a hypothetical situation to try and explain this.
We have a population of common brown skroats. Common brown skroats spend most of their time hanging out on tree trunks. There is a fairly common mutation among skroats that will turn the offspring of a brown skroat day-glo orange. The general population, being brown, is rather hard to see when sitting on the brown bark of a tree, but one of the mutated day-glo orange skroats can be seen from quite a distance. As such, the day-glo orange mutants are seen and devoured very quickly, leaving behind their brown siblings to reproduce and make more brown skroats. So long as the color of the bark of the tree does not change, the selective pressure will act to keep skroats the brown color that most of them are.

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Sounds a little like the moth camo example i've seen many times(and believe in). Ok., lets say your'e skroats are a type of moth . The bright dayglow orange wouldn't neccessarily occur all over the mutated skroat's body. If orange spots occured, they wouldn't always lead to the mutant being eaten. Mimicry is another survival trait. Some moths have spots that look like giant eyes.Some other traits would also allow the new(mutated) moth to survive. If it tasted/smelled bad, was toxic or poisonous for example. A lot of brightly colored animals are dangerous or just not good meals.Again I'm not saying there are no negative feedback systems in nature. I'm arguing against a general case. I think most extreme Stasis is due to isolation . Take Tribolites, Coalanths, and Catholic Scientist's crocodiles as examples. Water is a good radiation shield(less radiation induced mutations).Coalanths are very sensitive to light and hang out in deep caverns (I read). Tribolites and crocs also had/have the armor thing going for them. Edited by Simonsays, : Toxic typo.