Evolution and complexity

We're not perfect angels here, but you've been given a bit of a rougher time than is normally given to a professed newbie to evolution, and I think it's because you said "I am a scientist..." in Message 19. People are therefore holding you to a higher standard than they would your average newbie who possesses little to no science background. Certainly the misconceptions and questions you're asking are pretty much the exact same ones those with no science background have, and you come across not as a scientist of the stars who happens to be unfamiliar with biology, but instead as someone unfamiliar with science altogether, so it's a bit puzzling.--Percy

Hi Simonsays,I'm puzzled about why you have a problem with this: Those three statements are correct and consistent. Can you explain where you think the problem lies?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

You're using the word "warrant" in a way no one here is familiar with. Here's the definition of warrant from Answers.com: Which of these definitions are you using? 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.--Percy

No, it's in there, but let's look at your own analogy first. So the microwave energy being absorbed by the coffee and causing the coffee to heat up is selective pressure. Hopefully I have this right and am just rephrasing what you just said. Let me know if I have this wrong, though, because there's no point in you reading on if I've got this part wrong.So you go on to say: Is the microwave off now? Because if the microwave is the ultimate source of selection pressure, then turning it off removes the selection pressure, and once the selection pressure is gone there should be no change in allele frequency.Or is the microwave still on? If so, then why do you mention heat flow in connection with changes in allele frequency?In other words, I think you're confused about which part of your scenario is analogous to selection pressure. Is it microwaves or heat flow?If we go back to my analogy you'll see that it more neatly explains the situation. Don't worry about how the coffee got hotter than the surrounding air, it just is. The coffee will attempt to reach equilibrium with its environment by allowing heat to flow from it to the air. The heat flow is analogous to changing allele frequencies, and how close the temperature of the coffee and air are to each other is a measure of adaptation. Zero temperature difference corresponds to perfect adaptation where no more heat flows and allele frequencies no longer change.--Percy

No, I left it out intentionally because my analogy applies to your "general case" objections. I think it must be a case of this particular analogy just not working for you, but let me give it one more shot.A population experiences changing allele frequencies when it is not well adapted to its environment. A cup of coffee experiences changing temperatures when it is not the same temperature as its environment.A population experiences relatively stable allele frequencies when it is well adapted to its environment. A cup of coffee experiences no change in temperature when it is the same temperature as its environment.In this analogy, a population is in equilibrium with its environment when it is well adapted to it. And a cup of coffee is in equilibrium with its environment when it is the same temperature as it.Changing allele frequencies are what happens to a population not in equilibrium with (not well adapted to) its environment. And net heat flow is what happens when a cup of coffee is not in equilibrium with its environment.The purpose of the analogy is to illustrate how organisms don't need to "know" they should change or stop changing. The change just happens through the application of the known physical laws of the universe. In the same way, the coffee doesn't need to "know" when it should start or stop changing temperature. The application of the known physical laws of the universe will cause the coffee to stop changing temperature as soon as it is in equilibrium with (same temperature as) its environment.And just as evolution doesn't stop just because a population is well adapted to its environment, heat flow doesn't stop just because a cup of coffee is the same temperature as its environment. But any minute change in the population away from equilibrium will put it out of equilibrium with its environment (it will be less well adapted), and the natural laws of the universe strive to restore equilibrium (restore good adaptation). And any minute change in the temperature of the coffee will put it out of equilibrium with its environment and again the natural laws of the universe will strive to return it to equilibrium, so that even though there might be minute temperature changes resulting from minute heat flows in and out of the coffee, the net heat flow will be zero.If this analogy doesn't work for you then we'll just move on to some other explanatory approach.--Percy

I gather you say this is because you're thinking of selection pressure as independent of adaptation. For example, you say this: So if we consider a relatively unchanging environment, you would consider the selective pressure of that environment to also be a constant. I think you're probably saying this because there is always selection occurring, but what you're missing is that the net result of this selection is no change. It is net selection that's important, not the constant selection events that eliminate offspring that are too far from good adaptation. This constant selection that results in zero net selection is analogous to the coffee cup at the same temperature as its environment, since there is a constant exchange of heat with the environment back and forth, but no net heat flow, no temperature change.I think you're thinking of a population that is already well-adapted to its environment as being kept there by an active selective pressure, as if it were a force pressing in on it from all sides and keeping it in one place. But place a ball bearing in a bowl and it will come to rest at the lowest point where it experiences no forces. It is only when you give it a small nudge that it experiences forces that return it back to lowest point.So heat-differential does have some good analogous qualities to selection pressure. When there's no heat differential, there is no reason for temperatures to change, they're already the same. In the same way, when there's no selection pressure because the population is already well-adapted to the environment then there's no reason for the population to change.--Percy

Right. I covered that. That's the part where I described the coffee cup as still exchanging heat back and forth with the environment (you can imagine this at the molecular level if you prefer, with molecules from the coffee exchanging momentum with molecules from the environment through collisions), but since the coffee is at the same temperature as the environment the net result of these dynamic exchanges is zero.--Percy

Perhaps your use of "warrant" is standard terminology with people you usually talk with, but no one here is familiar with it. If you want to be understood then you'll want to use words in ways your audience understands. Otherwise we'll end up wasting lots of time trying to figure out what you're saying instead of discussing the topic. Just like now. I'll second Dwise1 on this. There have been many attempts at explanations in this thread, and while we can tell you have problems with them, it isn't at all clear what those problems are.--Percy

You're saying that a book for middle school is using warrant in an obscure and non-standard way? Could you provide the text on p. 70?By the way, the title is What's Darwin Got to Do With It: A Friendly Conversation About Evolution. Dwise is not claiming ideal genomes exist in nature. You're taking his simplifications made for the sake of exposition and somehow concluding that he's claiming that's what exists in nature. He's not. Negative feedback mechanisms abound everywhere. They are the primary type of feedback mechanism for producing useful results by keeping systems within reasonable operational limits. Positive feedback mechanisms spiral out of control, like microphone feedback. If you're looking for a one-word synonym for evolution, you're not going to find it. Change over time, adaptation over time, descent with modification, natural selection, these are all part of the definition of evolution. How much each is emphasized depends upon how much detail you're seeking.--Percy

Why would you want to single me out since everyone's telling you the same thing? But you did claim it was standard terminology. You chastised people for not understanding what you were talking about.A quick websearch reveals that you're talking about the work of Stephen Toulmin, where he suggests a nomenclature for logical analysis that includes the divisions 'claim', 'evidence' and 'warrant.' My guess is that your book is attempting to unsuccessfully apply Toulmin's nomenclature and analysis.You can find a description of Toulmin's work at the Wikipedia entry for Stephen Toulmin. In the introduction it says that he sought "to develop practical arguments which can be used effectively in evaluating the ethics behind moral issues. His works were later found useful in the field of rhetoric for analyzing rhetorical arguments."In other words, his work hasn't been found useful in scientific discussions, and both you and your book's attempts to do so only result in confusion. You're allowing yourself to be unduly influenced by the writings of someone with a poor grasp of both Toulmin argumentation and its appropriate areas of application. You can find the Socrates example of a logical argument at literally thousands of websites. If you check a few out you'll see that none use the term "warrant."But that's not what's important. Let's say for the sake of argument that you're dead right and Toulmin argumentation is precisely what's required here. Unfortunately for you, you've wondered into a bizarro world where no one is familiar with Toulmin argumentation. If you want to be understood you'll have to adjust your terminology.--Percy

"Everyone" only refers to the participants in this thread, of course. Examples would be Crash in Message 56, Chiroptera concurring in Message 57, jar in Message 70 and dwise1 in Message 64It was more than "a handful of people not being familiar" with your use of "warrant" - no one could figure out what you were on about.Your usage is not only unfamiliar to the "man or woman on the street", it's unfamiliar to scientific discourse. As I explained, the terminology is part of Toulmin analysis, a specialized approach suitable for fields like rhetoric. You won't find it anywhere else. As I suggested before, check out as many of the thousands of sites using the Socrates example as you like and see how many use the term "warrant" to explain it. You tried using terminology that other people understand and it didn't work as well for you as what's happening now? You enjoy general derision at your inability to express yourself clearly? Except that you weren't clear, and that's because you don't have a clear understanding of Toulmin analysis, nor does your book, and no one else here is familiar with it. A lack of understanding is reflected in both you and your book's usage of the word "warrant". Just contrast you and your book's usage of it with the clear exposition of it at Wikipedia. You even referred to my explanatory analogy as a "warrant", which is how we ended up discussing this instead of the topic.I can only repeat what I've already said. If you'd like to be understood so that discussion can focus on the topic instead of on your odd word usage, then speak plainly using common definitions. When you require unfamiliar terminology, then introduce the term and define it.--Percy

I don't know if Simonsays will return, so I'll post a couple thoughts deriving from the recent experience with Simonsays, and also with IamJoseph.Good writing is simple and easy to understand, but there's a general perception among laypeople that scientific writing is the opposite. This probably stems from exposure to unintelligible scientific writing, but the unintelligibility stems from their own unfamiliarity and hopefully not from unnecessary complexity or terminology in the prose.Some of those who bring this misperception here seem to believe that everyday words and modes of expressions aren't appropriate here, that it is necessary to use complex terminology and phraseology to communicate an air of authoritative knowledge and fluency. Some very old timers here might remember TrueCreation's early attempts at participation where he would try to shoehorn the most complex terminology he could into his messages, often with hilarious results (TrueCreation began participating while still a young teen - he quickly improved).What we should really try to do is use the most understandable terminology possible to communicate what we mean. Depending upon topic, this may require specialized terminology, but if a common word will do then we should use it. In other words, eschew obfuscation, er, I mean, be clear. --Percy