Whether you buy it or not doesn’t make it wrong. I didn’t say the environment was natural selection. I didn’t say the change was natural selection. I said it begins with the environment, or better yet as you pointed out better wording, the change in the environment.
The outcome for the other bird can’t be different for the same conditions, we agree. It’s food is still going to be there, under the same event.
then any given mutation would have equal probablilities of being passed on to the next generation well yes, for the genome of the survivor. No for the bird with the wrong bill. In this instance, only the bill counts. You have to survive first, reproduce second.
On the last part about the conditions, again, I wasn’t saying the climate was natural selection. I would have typed that in there if I thought so. I don’t see how it could be misread.
Those who wrote the spambot were acting purposefully. However, the spambot itself is not acting purposefully; to have a purpose requires intelligence, and the spambot is not even remotely intelligent.
I didn’t mean to say that the system was analogous to the environment. All I wanted to show was that the result of a random process needn’t be random. Do you agree with that?
Well, then I must confess I have no idea what you are getting at.
The mutations themselves can be seen as independent events; they just happen. Separate from the mutations, the set of parameters which determine how viable a given mutation will be are determined by the prevailing environmental conditions (which include elements such as climate, food availablility, predation, and so on). Given these parameters, there is only a small subset of the total possible mutations which can be viable - they are not all equally so. If an organism does not possess one of these viable mutations, it will be selected against.
Again, an organism may curse its fortune at possessing a non-viable mutation, but any such afflicted organism will similarly be selected against. Initally, it’s a crapshoot. Afterward, the results just get filtered.
Why not? Most environments are relatively stable, so are the various BBS and newsgroups. The environment does not change constantly.
So any messages that fails to comply with standard protocols cannot be posted. Similarly, any individual organisms that cannot adapt to the environment for any number of reasons will be winnowed out.
Finches aren’t designed to be posted, but their ultimate purpose is to reproduce, which is a future event.
How did the finch that had the correct bill for survival in my scenario adapt?
Two birds with two types of bills for two types of food are living on an island.
Then a change in the environment.
Then the loss off food for one and that bird is ultimately selected against.
The point I’m making here is to take a look at the bird that survived. It didn’t change for the environment. The new environment just happend. This bird didn’t change at all. It has possessed the helpful mutation for eons. It didn’t quickly mutate for the new environment. Nor did it, years before, plan for a possible change in the environment.
This is what I mean when I say that mutations are not imput to a system.
The environment is constantly changing either slow or fast and off and on. The finch that was selected against was also equipped to reproduce but survival is required first.
Where we disagree on the “random” thing is on my point that the results are without conscious choice.
This only makes sense if we are discussing populations of birds. Not individuals. You are using individual terminology alot, and is starting to make me wonder if that is part of the confusion.
Let me rephrase your scenario and then I will comment.
Two populations of birds live on an island. Each population consists of a distinct species, with its own type of bill for its own type of food. The twp species are not competitors for food.
Then a change in the environment. This change causes the food for species one to dissappear.
Species one, quickly dies out, every last one of them. Species two goes on as before.
I will now comment, based on the assumption that this is what you meant.
The first thing, nothing in this scenario speaks to evolution of species two. Species two was uninvolved in this scenario. It is a mere disctraction.
This does speak to the evolution of species one. It has just become extinct. That is a valid evolutionary event. It has happened many times before, and will continue to happen in the future.
This is a great example of how species dissappear. I don’t see how this proves your point at all.
Big problems with your reasoning:
As I pointed out, this problem says nothing about the species that lived. As far as the surviving species is concerned, the environment didn’t even change. It’s food source wasn’t effected. Any reference to what did or did not happen with that species is a red herring.
This does agree with what we have been saying about environment and mutations being input to the system. The environment changed in such a way the the only food source for one species dissappeared. We can predict that if that there were not some number of individuals within that population with some mutation that would allow them to survive on an alternate food source, that species will die. This is a valid example of how things happen. Input is random, the system is still deterministic.
The key insight to natural selection that appears to be missing is the distinction between a population and an individual. From an individual’s perspective, surviving the game is a pretty random affair. For a population, it is not the same picture.
Mutation is what puts variety in a population. If a population has no variety that already can survive a change in environment when it happens, the species will die out. That is a valid outcome. The environment works just like a sieve.
Wrong, In this case, the bill mutation is the same for all in that species, respectively, as seen in that for the selected against species, it was unable to use its bill for other food. Natural selection only selects against a bad mutation.
As far as the surviving species is concerned, the environment didn’t even change.
This is EXACTLY what I was getting at. NEITHER did the species with the good bill. Any reference to what did or did not happen with that species is a red herring.
Wrong. Dead things don’t evolve. (one of my hidden points)
How did the species with the good bill adapt for the new environment?
If after the event that changed the environment:
This bird didn’t change at all.
AND - It has possessed the helpful mutation for eons.
AND - It didn’t quickly mutate for the new environment.
AND - Nor did it, years before, plan for a possible change in the environment.
Where is the “adapting to fit the environment” if both the environment and the bird are the same after the change in the environment?
I think this is where your key misunderstanding is: “adaptation” is not an active process. Natural Selection is a negative filter: traits are selected against, not for. Those populations which survive this filter intact are said to be “adapted” to their current environment.
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But again, you are not taking into account the true nature of selection: it selects against, not for. If the environmental variables change, the set of non-viable mutations will change as well. Natural selection is the process whereby those organisms possessing such non-viable traits are removed from the gene pool. If those organisms make up an entire population (that is, the now non-viable traits are established throughout), then the population dies out; if all such populations are affected, then the species as a whole goes extinct.
In the case of the organisms/populations/species which survive such environmental changes, they have not adapted to the new environment - they were already adapted to a larger range of environmental variables. This relates back to a previous post (in another thread) I had made with respect to generalists vs. specialists: generalists have a greater degree of tolerance for various environments, thus have greater survivability when the environment changes.
Since non-detrimental mutations are essentially invisible to natural selection, such traits will likely persist, and can eventually permeate the entire population (through such mechanisms as genetic drift). Such traits may do nothing for the organism in the present. However, a future environmental change may result in those traits entering into the survivability equation: those who possess them will survive, those who don’t, die.
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But, the finch that survived, simply by virtue of not having non-viable traits in the new environment passed the natural selection filter.
Please read my post again. I hope it is clear that I was speaking of the species that survived at that point.
Somewhere, though, there is a fundemental disconnect. None of your posts indicate that you understand the idea of natural selection. You consistently give examples that evolution and natural selection do not support. Then you show the example is false. Then, you hold that up to show that evolution/natural selection is wrong. That makes no logical sense. Proving something wrong that a theory does not say, has no value concerning the theory. What you are proving is this; your personal understanding of evolution/natural selection is false. Bravo there, but… since, your understanding of it, and the true application of it don’t seem to be the same, you aren’t getting anywhere.
Okay, so its only a figure of speech, they are “adapted”.
Hmmm… So wouldn’t you have to frown on the phrase “become adapted”? What if I was to tell you that I have a biology text book that uses the phrase “become adapted” when natural selection is part of the adaptive radiation of the finches on the Galapagos Islands? The book reads: “Because of natural selection, each population became adapted to a particular habitat on its island.” Interesting, she doesn’t say just that “they were adapted” or “said to be adapted”. The author boldy says that they become adapted.
But no, they couldn’t have already been adapted, having all the mutations needed for making use of the limited food in the beginning…right? They had to become adapted…right?
I’ll Xerox the text of the book and snail mail it to you if you want.
You are, at this point, nitpicking grammar, not making an argument. Whether I say “they have adapted” or “they have become adapted” or “they can be said to be adapted”, I mean the same thing.
I admit my previous statement regarding adaptation is rather an oversimplification: adaptation involves more than simply surviving. Adaptation is the cumulative result of multiple filterings. Nevertheless, the initial statement which began this detour stands: natural selection is not a random process. The selective pressures acting on any given organism are dictated by the environmental conditions acting upon it at that time. Traits in any survivors can either be directly beneficial to the organism, or they can be neutral. Even neutral traits, however, can come to represent either a liability or an advantage in future environments (just as now-beneficial traits can eventually become neutral or detrimental).
No it’s not simply grammar. I knew you try to say so, as if there is no difference in becoming adapted and to already be adapted or becoming fit and already being fit. Didn’t you see I was going to end up pluggin natural selection into adaptive radiation?
See, we know that natural selection doesn’t really change anything. The environment doesn’t change for the survivor and the surviving finch doesn’t change. Natural selection only results in something that was there all along.
A single species of finch invades an island that has a limited supply of food. But there is other food there only the finches can’t make use of it because its bill that doesn’t favor that food. Since the environment doesn’t change for the finches that are able to survive and reproduce, then how can we say that natural selection wouldn’t act on the finches that have a slight mutation apart from what is normal for the majority of that species? That slight mutation would not be neutral to their environment. It would most certainly put the finches of that population in the rear in terms of competing for food because a thin bill is not as efficient as a thick one (or vice versa).
For this, they would have been selected against because their bill wasn’t the best fit for their environment. Instead, you want to believe that they were exempt from natural selection and jumped right into adaptive radiation. It doesn’t add up. Natural selection doesn’t work sometimes and not others.
To put it bluntly: wrong. Very wrong. In all ways wrong. Natural selection removes those organisms which are not suited to a given environment from the population. How can that be “not really changing anything”? You also fail to realize that the mere removal of said individuals constitutes a change in the survivors’ environment. As I said before, the “environment” is not simply the climate or the available food, or any other single factor. It is the sum total of all influences on an organism. Nor are organisms simply at the whim of said environment; they affect it as well.
“What was there along” is an organism’s phenotype. However, the usefulness of that phenotype will change as the organism’s environment changes.
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No, that isn’t what I want to believe. If you’ll recall, you’re the one who made the statement “natural selection doesn’t really change anything”.
Adaptive radiation is the (relatively) rapid divergence of a single lineage into multiple niches. When a population of finches invades an island, the environment for those birds has altered. Natural selection continues its work, using the new variables: those individuals who possess phyletic traits suitable to this new environment (complete with limited food supply) will survive; those who do not, will perish.
Over time, as indiviudals move to fill vacant niches, selective pressures will begin to differ from population to population. Given sufficient time (without overly drastic changes to their respective environments), these populations will become more specialized in their respective niches. This process is what results in adaptation. Note, however, that the organisms do not set out to adapt to their niches; adaptation is the result.
I’m not sure how you can translate that into “sometimes natural selection works and sometimes it doesn’t”. It’s always working. Nowhere did I say that any organism is exempt from the process. Nor can you have adaptative radiation without natural selection (adaptation is, by definition, the result of natural selection, as opposed to changes which result from other types of selection or from mechanisms such as genetic drift).
No, its not wrong. Because it’s not changing anything from the perspective of the already surviving and reproducing member.
This is only after the selection. The survivor survives and is able to pass on its (same as before) genetic information the same as it was before. Get that part, the same info as it would have had the other members of its population never been selected against. What you call a “change” is only a greater opportunity to do the same thing it has always done.
You’re focusing only on the term ‘phenotype’ as if you’re reading from a book. That’s why I made the phenotype in the example one that the finch’s survival depended on. In this case the correct phenotype meant survival; the wrong one meant death.
Thats a verbose definition of adaptive radiation but I just want to nitpick and point out you didn’t once use the word species. “Adaptive radiation results in new species” is what you meant to say somewhere in there. Hey, just nitpicking.
The individual’s perspective is irrelevant to the way the mechanism works. From our perspective, the sun appears to orbit the earth.
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That’s because the survivors were not selected against. Get that part: the survivors were not selected against. And that “same genetic information” now plays a different role than it did before.
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I’m using the term “phenotype” because that’s what natural selection works with. Only those genes which are expressed, and how they are expressed, matter. Thus, “phenotype”.
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No…no, I didn’t meant to say that. Adaptive radiation can result in speciation. Adaptive radiation is as I stated: “the (relatively) rapid divergence of a single lineage into multiple niches.” Or, if you prefer, “the divergence of a single lineage into multiple adaptive forms.” Take your pick. Unless these adaptive forms result in reproductive isolation (whether as a direct or indirect consequence), adaptive radiation, in and of itself, is not sufficient for speciation. Even in such cases where adaptive radiation does result in speciation, it is thought that sexual selection, in addition to natural selection, plays a significant role.
This is the way the probability of evolution was explained to me:
Spell out the entire Webster’s Dictionary with Scrabble tiles. Throw them in a huge bag, shake em up and pick the tiles out one by one until you’ve completely pulled the letters in the correct sequence.
How long will that take? Billions of years I assume. But eventually it will happen. It could conceivably happen on the first attempt.
That’s how scientists get over the probablity issues in evolution. Do I buy it? It’s logical I guess. But I also know it’s fruitless to debate faith.
How about this: take a bunch of Scrabble tiles and throw them in a bag. Pull them out one at a time. Now, look at what you have. What was the probability of that exact sequence occuring?
Scientists don’t "get around’ the probability issue, because it isn’t an issue with them. It’s an issue with Creationists that the scientists are then forced to address, lest ignorance spread.
With all due respect, may I ask who explained evolution to you that way. Because even with my limited knowledge of evolution, that is not even wrong (check Wolfgang Pauli if you don’t get that).