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Newsgroups: talk.origins
From: be...@pop.networkusa.net (Bennett Standeven)
Date: Fri, 16 Jan 2004 00:41:15 +0000 (UTC)
Local: Thurs, Jan 15 2004 7:41 pm
Subject: Re: Stacking the Deck
seanpitnos...@naturalselection.0catch.com (Sean Pitman) wrote in message <news:80d0c26f.0401141825.4784ad85@posting.google.com>... OK; the ice cream cones are probably found in shops; so given any > howard hershey <hersh...@indiana.edu> wrote in message <news:bu46sv$srt$1@hood.uits.indiana.edu>... > > > Consider the scenario where there are 10 ice cream cones on the > > Except that is NOT what evolution does. Evolution starts with an > Yes . . . so start the blind man off with an ice-cream cone to begin cone, odds are that another cone is just a few inches away. This is still true even if there is only one shop in the USA. > > Up is good. Down But it does not matter, because the blind men always start out in the > > is bad. > Ice-cream cone = Good or "Up" (to one degree or another) or even > No ice-cream cone = "Bad", "Down", or even "neutral" depending upon > > Flat is neither good nor bad. > Exactly. Flat is neutral. The more neutral space between each "good" ice cream shop, with an ever increasing selection of cones within arm's reach. Of course, they'll never find any of the other shops, but so what? [...] > > And > Actually, the mesa itself, every part of its surface, represents an > > If this topography of utility only changed slowly, at any given time it > If all the 10,000 blind men started at the same place, on the same blind men on them. > > But you were wondering how something new could arise *after* the blind But since the current mesa is a local high point, there is nowhere for > > men are already wandering around the mesas? The answer is that it > > depends. They can't always do so. > And why not Howard? Why can't they always do so? What would limit them to go. [...] > > Let's say that each mesa top has a different basic *flavor* of That's not a "problem", it's the whole point. Evolution by definition > > ice cream. Say that chocolate is a glycoside hydrolase that binds a > > glucose-based glycoside. Now let's say that the environment changes so > > that one no longer needs this glucose-based glycoside (the mesa sinks > > down to the mean level) but now one needs a galactose-based glycoside > > hydrolase. > You have several problems here with your illustration. First off, involves gradual changes, in which new systems have similar functions and definitions to the old ones. > Also, their level of functional complexity is relatively I don't know exactly what "galactose-based glycoside" is, but > low (like the 4 or 5 letter word level). something tells me that it takes more than 4 or 5 amino acids to bind to it. > Also, you must consider the likelihood that the environment would change Yes. More likely the galactose was always there, but was ignored in > so neat so that galactose would come just when glucose is leaving. favor of the glucose, until the latter disappeared. > Certainly if you could program the environment just right, in perfect That's pretty easy; following the mesa analogy, either the high mesa > sequence, evolution would be no problem. But you must consider the > likelihood that the environment will change in just the right way to > make the next step in an evolutionary sequence beneficial when it > wasn't before. drops to be lower than the formerly low one, or the low one rises above the formerly high one. Happens all the time. > The odds No; the chance that two sequences will interchange in relative fitness > that such changes will happen in just the right way on both the > molecular level and environmental level get exponentially lower and > lower with each step up the ladder of functional complexity. does not depend on how complex they are. > What was so easy to evolve with functions requiring no more than a few Quite good, I'd say. I can easily imagine the relative fitness of > hundred fairly specified amino acids at minimum, is much much more > difficult to do when the level of specified complexity requires just a few > thousand amino acids at minimum. It's the difference between evolving > between 3-letter words and evolving between 20-letter phrases. What > are the odds that one 20-letter phrase/mesa that worked well in one > situation will sink down with a change in situations to be replaced by > a new phrase of equal complexity that is actually beneficial? - "Today we'll talk about unicorns" exchanging places with that of "Today we'll talk about unicode", for example. Those are 25-letter phrases; making them even longer would only increase the number of nearby phrases with potential value. > Outside of intelligent design? That is the real question here. Yes; the higher the lever of complexity, the more likely that the new > > Notice that the difference in need here is something more > He certainly may be extremely far away from the chocolate with almonds ice cream cone is nearby, since the fancier (more complex) flavors tend to appear in the stores with the largest selection. > > Changing from one glucose-based glycoside hydrolase to one with a You don't; if you want to get from chocolate to strawberry, you need > > slightly different structure is not the same as going from chocolate to > > jalapeno or fish-flavored ice cream. Not even the same as going from > > chocolate to coffee. The "island" of chocolate with almonds is *not* > > going to be way across the ocean from the "island" of chocolate. > Ok, lets say, for arguments sake, that the average density of to do it early on, when the distance is smaller. That's why fundamental differences between organisms (such as between chocolate and strawberry ice cream) are taken as evidence that they are only distantly related. > You see, the overall average density of cones is still significant to > > It will be nearby where the blind man is. *And* because chocolate with No; the blind men at the other clusters reached them when they were > > almonds is now the need, it will also be on the new local high mesa > > (relative to the position of the blind man on the chocolate mesa). The > > blind man need only follow the simple rules (Up good. Down bad. Neutral > > neutral. Keep walking.) and he has a good chance of reach the 'new' local > > mesa top quite often. > And what about the other clusters? Is the environment going to change still a part of this one. Eventually the clusters split apart and "drifted" away from each other. (Much as galaxies "drift" apart due to cosmic expansion.) [...] > > My > Agreed. > > with the closest flavor to the new need > This is where we differ. Say you have chocolate and vanilla. Getting cream with strawberries or some such. Similarly, we would not expect birds to evolve jet engines, as they [...] > The suggestion that absolutely all of the clusters are themselves It isn't necessary that they _all_ be clustered in that fashion; only > clustered together in a larger cluster or archipelago of clusters in a > tiny part of sequence space is simply a ludicrous notion to me - > outside of intelligent design that is. Oh no, you, Robin, Deaddog, > Sweetness, Musgrave, and all the rest will have to do a much better > job and explaining how all the clusters can get clustered together > (when they obviously aren't) outside of intelligent design. that some of them are. You must Sign in before you can post messages.
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