mutation and evolution

(This thread is a spin-off from Message 49 by Spofforth in the thread Teaching the Truth in Schools in the Education and Creation/Evolution forum. --Admin)

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In what population of organisms, except bacteria which I am guessing that you are not making the assumption that they can evolve immediate multicellular and complex capabilities, are there hundreds of billions of organisms?

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I think you misunderstand. How did you calculate the odds? Did you consider that there are astronomical numbers of experiments running simultaneously and that this has been occurring for a couple of billion years?

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If evolution can only happen at the population level, there still is not the grand scale number of organisms necessary fro mutation to be the driving factor.

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Attempting to cut the numbers by appealing to populations isn't relevant to the issue. Consider: Ten species with 100,000 individuals each. For simplicity, lets say they reproduce at the same rate and produce one offspring per generation. Each generation can be considered as 1 million genetic experiments-- ie, each generation produces 1 million individuals, each with a mutation or two. That these mutations do not cross species does not cut the total number of mutations. It does mean that the mutation is limited to the offspring of originating population. Perhaps nine of the ten species die out, but the tenth survives as it had the lucky mutation.

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Only the students that have demonstrated an understanding of biological systems and the scientific method should be allowed to investigate further.

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Funny, you want student to understand biological systems but do not wish to expose them to a key component of biology.

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What do you think a modification in the genetic code is doing? It is coding for a new amino acid which is coding in turn for a new protein.

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Ah... my mistake. Usually, creationists who make statements like "mutation can't create new proteins" mean "a completely new protein unrelated to any other." Or something very much like that. The reason creationists opt for this restricted definition is that mutation can and does modify existing protein and this happens quite a lot. So really, you've cut the rope from under yourself.But what is with the "coding for amino acid which is coding for a protein" part? Amino acids don't code for anything. They are components, like Lego.

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If the protein happens to fit with the other proteins that are present in the organism that organism might survive the mutation.

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Ta Da!!!!!! You are almost there. See, it isn't so hard to understand.

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Although the mutation is present it may not even get the chance to thrive in an environment and the organism may never pass it on to the next generation.

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Right-o. This would be natural selection.

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If we do not know the origination of the original genetic code we cannot teach that all organisms originated from the same lineage despite the fact that some evidence might point in that direction.

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What if all the evidence points in that direction?What you are basically arguing is that if we don't have all of the information we can't teach what we do know. We don't have all the information for any subject. Would you like to ban all knowledge, as it is all incomplete?

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If you want to be truly neutral in the science classroom no theories can be taught, just the scientific fundamentals that would allow the student to investigate further on his/her own.

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The idea of being 'truly neutral' sound pretty good until you realize that being neutral means presenting theories which have no evidence right along side theories that have great deals of evidence.No theories? We may as well call science class "nap time" then, because there won't be anthing to teach. Everything you learn is based upon something containing that dirty word-- theory.------------------
No webpage found at provided URL: www.hells-handmaiden.com[This message has been edited by Admin, 02-25-2003]

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The problem I see with that line of reasoning is that if you take into account that a new species can only arise from a previous species, according to evolutionary theory, then you can only take into account the mutations that occur within the parent species.

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This is a repetition of the first objection you made, and I responded to it.

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The key component I would want them to know before knowing any theory is the scientific method.

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Why do you hold this up as so important, but dismiss the results it produces? Very few things have as much evidence behind them as does the ToE.

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I just meant that if the right amino acid was not in place then the protein would most likely be an irrelevant part of the organism.

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If an amino acid is not in the 'right' place then you have a mutant protein and I supppose the change is likely to be irrelevant, but sometimes it makes a difference.

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My contention would be that the existing protein is not modified all that frequently because the point mutations that would be most likely to survive often do not even change the protein.

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Have you bothered to look it up? I've found quite a few examples and posted a couple of them for you. Have you decided to look the other way?

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If you are looking at the codes for amino acids there can be several variations of bases that code for each one thus lowering the frequency of mutations that cause protein changes.

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Do you mean that several different stretches of DNA code for the same protein? Well, sure. And they code for a slightly different version of the protein. You are talking about mutation and the effects of mutation but claiming the opposite.

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I would certainly not argue against natural selection, I would however argue that it is acting on variation that is already present in the population.

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It does act on variation that is already present in the population, in a sense. When you get a copy error you automatically have a new variant in the population.------------------
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Spofforth,Consider the human species. I did some quick math and worked out the following. If we assume the human population at an even 5 billion and assume the figure of 4 mutations per individual, as suggested in the article I cited, and further assume that 1 in 100,000 mutations are beneficial ( this article suggests that in fact the rate of beneficial mutation is 1 in 1000 ), you find that there should be 18,000 or so new beneficial mutations in the current generation of humans. That is quite a few. Consider that this process has been in place for billions of years, stretching through our line right back to the beginning. Nowhere along that line do we have to worry about 'trading' genes between species, as is a concern of yours. Every creature in our lineage can be considered the same population.As for the mutation rates being reduced due to populations being divided, pretend that you are a scientist running an experiment. You want to track mutations in 1000 bacteria. You don't want to watch all 1000 personally, so you divide up the population into ten sets of 100, each set to be watched by a student. The mutation rate is the same as if you hadn't divided the population. The total number of mutations is the unchanged. Imagine that you put your 1000 bacteria into a freezer in one lump. Ten bacteria have a mutation that allows them to survive and reproduce. The rest die. Now back up, and put those ten sets of 100 in the same freezer. The same ten that survived before, survive now. The rest die. The result is roughly the same. If these ten are in the same population then you'll have a flurry of life in one petri dish and 9 dull dishes and potentially one new species. If the ten are divided amonst the various dishes then you'll have several new species ( potentially ). But the total mutations and hence the total potential for adaptation remain the same.------------------
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Yes there is evidence that tends to lead in the direction of evolution.

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That is a serious mistatement of fact. Since Darwin proposed his version of evolution 150 years ago, it has passed every test. Every bit of evidence that we've been able to scrape up has fallen into place in support of the ToE. Despite what creationists promulgate, there is no real challenge to the theory at the moment and there never really has been.

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I just find it hard to promote a theory as fact if the lineage of DNA cannot fully be traced from generation 1 to generation x.

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Really? Can you trace your lineage back even 2000 years? How about all the way to the beginning 6000 years ago? Seems this would be an easier task but can you do it? Nope. Guess we can write off decent from Adam then. Did you read the Jet's Challenge thread? EvC Forum: How does evolution explain the gaps? The same issue came up there.

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I have looked at them and they are discussing what I would consider microevolutionary changes.

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All evolution is micro in the short term. That is, a horse does not suddenly give birth ocean adapted offspring. The change is slow and takes much longer than the lifespan of a human. We only get to see a few seconds of the ball-game. There is nothing anyone can do about this. Relationships of long duration we have to infer from the evidence we have at our disposal.

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I believe that microevolutionary changes do occur because there is variation within every population.

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Yes, indeed. Evolution does occur because there is variation within a population. Your mistake is in assuming that, or insisting that, this variation is stable. It isn't. Mutation is rampant. And it does produce variant individuals. Hence there is no hard micro/macro barrier. The distinction, as creationists use it, is just a smoke screen.

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The thing that I cannot conceive, even given the possibility of billions of years, is that microevolutionary changes could lead to the wide scale variation in organisms today.

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Yet you believe in... what.... ? Magic? A creator unlike anything you experience who poofed everything into existence? That doesn't make sense. Evolution has reams of evidence and more comes to light every day. The alternative has zero evidence-- not one shred. Yet you are incredulous about evolution? It simply does not make sense.

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The changes that are seen cause organisms to fit into specific niches and occur in response to environmental changes, ie. presence of nylon and not carbohydrate or pesticide resistance, however the populations tend to rebound as the stimulus is removed and the fitness of the "mutant" decreases in the population.

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Changes don't 'cause' organisms to fit into niches. It isn't teleological.Fifty or a hundred years ago there would have been no nylon for the nylon-bacteria to digest. Why would it have code in its genome for this ability? In other words, if you wish to describe all adaptation as variation within existing DNA, you have to explain why the bacteria would have the ability to eat nylon prior to nylon having been invented. Why would its genes code for the ability to eat something that was yet to exist for it to eat?We have plenty of examples of speciation-- ie. examples of populations splitting into variant groups THAT CANNOT INTERBREED. That pretty much kills the idea that populations 'bounce back' in all cases. Once the split occurs, there is no going back.------------------
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Puntuated equilibrium to explain gaps in the fossil record, modern synthesis to correct for Darwin's nonrandom mutation?

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Punctuated equilibrium is the idea that rates of change varies. It is not a contradiction or a challenge any more than stating that your car can travel at any speed between 0 and 100 contradicts the idea that your car usually travels 45 or 50. Darwin assumed a steady rate of change but that assumption is not integral to the idea of evolution as decent with modification. PE appears to explain more data. It encompasses Darwins original idea, and adds to it. It does not invalidate the ToE.Darwin did not know about genes and genetics. No one, at the time, knew about genes. Even Mendel, whose name is sure to come up, didn't know about genes per se. The modern synthesis adds this information to the ToE.Imagine that someone writes a set of instruction for building a car. Then, a while latter, someone else realizes that those instructions do not include some principles of aerocynamics and so adds those principles to the origin set of instructions. Does that addition invalidate the original set of instruction? Or that even the IDEA of building a car is invalid?

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Sure you can make inferences from the evidence, but that does not make a theory fact.

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Put it in more familiar terms. The police come upon a murder scene. All they have is what they find at the scene. In other words, all they have are a few details. They gather this evidence, or what they think is evidence, and carefully analyze it. A particular carpet fiber identifies an auto manufacturer. That sort of thing. Eventually the police accumulate enough evidence to make an arrest. The DA tries the accused and that person is found guilty of murder and imprisoned. Yet this is all on the basis of "just a theory" that was constructed by analyzing much less evidence than we have for evolution. So, because it is "just a theory" do we consider the case unsolved and let the killer go free? After all, no one was there to SEE the murder so we don't have any 'real' evidence. All we have are inferences and theories, not 'facts.'

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Perhaps chromosomes were designed with the ability to alter genetic material in response to environmental change.

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Perhaps? Where is the evidence? It seems like this sort of thing should be easy to prove. You should get the same mutations for the same conditions, assuming you start with the same reasonable similar individuals.This should also mean that species should not ever go extinct, because their chromosomes would alter themselves to fit new conditions. This would be a hyper-efficient evolutionary mechanism.Neither of these conditions are verified by the data available. The is evidence of an increase in mutation rates in stressed organisms ( go figure ) but the mutations themselves are random.

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Intelligent designer: synthetic material will arise someday as a result of human intelligence designed by me, there may someday be a need for natural means of disposal, Poof --> nylon eating bacteria?

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Poof..... riiiight!!!!------------------
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A couple of things came to mind.

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The environment has changed (albeit back) so the result
would be for the trait frequencies to re-align.

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If the environment changes back to a condition similar to its original state, as you assume, then the selective pressure return to those that created the original species just as you say. And so the traits would tend to re-align. If the conditions change yet again to a third option the trait frequencies are not likely to re-align.In other words, if you have conditions A, a short time at B and then a return to A, the trait frequencies would 'bounce back' If, however, you had A>B>C, there would be no selective force driving the traits to return to conditions suitable for A.

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Of course no new species have been created via selective breeding
(that I am aware of) so that still remains another issue.

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I'd argue that some dog breeds are in fact separate species, but that is just me. I'd argue that some breeds would never be able to cross-breed without human assistance.------------------
No webpage found at provided URL: www.hells-handmaiden.com[This message has been edited by John, 02-28-2003]

I thought you'd agree. I didn't really mean it as a response to you, but more as just clarification on a couple of points.------------------
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