Mutations

Does anyone know how much of evoloution is based off random mutation? Like what percentage of changes are postulated to be from mutations?

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You may be talking, but are
you saying anything?

That's a good question. There are a number of ways of producing a new genome.It would depend on how you define mutation. Would you include a copying error or only something caused by something like a cosmic ray? Do you include recombinations of the existing chromosomes of parents?How would you count changes? Everyone has a few changes from their parents. Do all changes count equally? What about changes that have large effects on the phenotype?What do you mean by 'based off'?

I was kinda thinking all kinds, though if someone could break it down into the different kinds it would be wonderfull. I'm currently working on a thesis, and I'm trying to collect some more data.What I mean by "based on" is, well... hmm I'm not so sure. I know that the main basis for evoloution is natural selection, but there has to be a heck of a lot of mutation for such diversity in the world to come from just natural selection. So the mutation that evoloution must be based on is what I'm talking about.

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You may be talking, but are
you saying anything?

Actually, NosyNed, I think the more important word that needs to be defined is what is meant by "random."Is there something that can happen all on its own without any consciousness involved? Or, is everything forced by an intelligence?You see, our biotechnology is sophisticated enough that we can create specific "mutations" in genes. I dare say that nobody would call these "random." They were deliberately plotted out and carried out by people intent upon it happening.How does one determine if something is "random"? When I take a coin and flip it, does it fall "randomly" or is there some consciousness involved in making it land the way it does?And if I were to take a handful of change and toss it on the ground and then take an identical handful of change and deliberately place each coin in the exact same pattern, by what criteria would you tell the two apart? And if you couldn't, why would a conclusion of them both being the product of "design" be more logical than a conclusion of "random"?And to muddy the waters even more, there is some evidence that environmental pressures can be so great and so highly specific that only certain specific mutations can survive. Even though no consciousness is involved in this (assuming that we agree that there are things that happen on their own), can the mutations really be called "random"? If the only result that can win is a 1, is it really a "random" result that all the dice we see in the next generation are 1s?

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Rrhain
WWJD? JWRTFM!

You need a real geneticist or better take some time with google yourself.Evolution is "based on" both mutations and natural selection. Selection needs variation to work on. Mutations by themselves would just produce random changes of no long term value to the organisms.If you count all 'changes' as mutation then I guess 100% of the novelty comes from them and selection pares them down.

Rrhain, we're not here to play semantics with eachothers points. All I want is an answer to my question, and as is plainly shown, you don't know it. It doesn't matter what I mean by "random".Thank you NosyNed for your help. It helped me to confirm what I had been suspecting, though I doubt I will stop looking for a more concrete answer.[This message has been edited by Rayne, 02-12-2004]

There is indeed a heck of a lot of mutation. Every new human individual carries some in the order of magnitude of a hundred new mutations.You really need to begin with a few basics of evolutionary biology; and there are a number of web sites that can help with this. The talkorigins archive provides Introduction to Evolutionary Biology; it provides background for people who encounter the subject within the context of evolution/creationism disputes.Another really excellent set of pages is provided by University of California Museum of Paleontology. It is Understanding Evolution, an evolution website for teachers. Here you will find an introduction on the nature of science; an Evolution 101 course, then additional pages specifically on supporting evidence, relevance, misconceptions, history, and aids for teachers.With respect to your specific question, you should note that natural selection does not give rise to diversity; in fact it acts to reduce diversity by weeding out what is not viable. Diversity arises by the introduction of variety, and this occurs primarily by mutation.So in a sense, all evolution is based on mutation; since this is the underlying source of variety. The moderating effects of selection work upon that raw material to maintain viability in many diverging forms. Do check out the links I have suggested for more carefully presented information; they should help you with the data you need. The talkorigins site is less glossy; but it contains more technical details on the different kinds of mutation that exist, especially if you start exploring further within the archive.Cheers -- Sylas

Ok, I concede the point that all of evoloution is based off of mutations.
Here's a new question: What percentage of mutations get passed to the offspring, and how many of these are mutations of acctual genes (not the codons that are not specific genetic codes)?Also, I am currently taking a tenth grade biology class, and I doubt that those sites will tell me more than I already know. I could just look in my biology book for that information. If you know of any other sites that are of a higher level, or if I'm wrong in judging how advanced these sites are please tell me.[This message has been edited by Rayne, 02-13-2004]

All mutations in the germ line get passed to offspring; and no others. That is, mutations which occur in sperm, or eggs, or in cells from which sperm or eggs are produced, will be passed on. No others.In humans, roughly 1 to 6 new non-silent germ-line mutations in coding DNA per generation, based on numbers from Rates of Spontaneous Mutation by JW Drake et al, in Genetics 148:1667-1686, April 1998; as discussed at the talkorigins archive (along with a lot more info on mutations generally) in the FAQ Are Mutations Harmful?. This could be out of date, but it should be in the ballpark for a good crude estimate. That FAQ goes into rather more detail about the different kinds of mutation than either of the references I gave previously. Drake's paper is on-line, but highly technical. The numbers are estimates, and the figure of 1 to 6 non-silent mutations in coding DNA, used in the FAQ, is an inference from raw mutation rates and the proportion of coding DNA in the genome. I think.Pinning down mutation rates is an active area of on-going research. I'm impressed. I have never studied this formally, but I have picked up a fair bit over the years on my own behalf. I'll rapidly defer to any professionals present. I think that the level of the talkorigins archive varies widely, but the more technical material would be above the level you indicate; yet within the range of a keen student who is willing to go beyond what is covered in school classes. The Berkeley material seems fairly basic, but covers quite a broad range of ground.But of course you may be the better judge of how well it matches your needs.Cheers -- Sylas(Added in edit. To give you an idea of the level and the credibility of material, the Introduction to Evolutionary Biology which I cited above, and a number of other files in the talkorigins archive, are included by Professor Rob Gedron of the Biology Department at Indiana University of Pennsylvania as a useful supplement for his undergraduate students in BI 112 - Principles of Biology II. Prof. Gedron lists these with a range of other resources at his pages on Evolution on the Web for Biology Students. Looking more closely at the Berkeley site, there are additional links I have missed previously. It also can take you quite deep into the material.)[This message has been edited by Sylas aka cjhs, 02-13-2004]

Rayne resonds to me:

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Rrhain, we're not here to play semantics with eachothers points.

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But that's just it: The semantics are important.We cannot have a discussion unless we agree on terms. Have you read the threads here? We have people who claim that "no new information can ever be created in the genome."And yet, they will agree that you can duplicate a gene and then mutate that gene. They claim that duplicating a gene is not an "increase of information" (all the while refusing to define what they mean by "information") since it's the exact same thing as what you already have, not "new."That is, going from "a" to "aa" is not an "increase" since the second a is exactly the same as the first a.They then claim that mutating a gene isn't an "increase of information" since all it does is change the information you have, not an "increase."That is, going from "aa" to "ab" is not an "increase" because "aa" is just as long as "ab."But don't you see how ludicrous that is? What on earth do they think an "increase of information" is and how could duplication following by mutation not be exactly that?How is going from "a" to "ab" not an "increase of information"? Even if we were to agree that going from "a" to "aa" is not it and going from "aa" to "ab" is not it, surely the two of them together is exactly it.That's why it is important. You brought up "random" and the tone of your post indicated that you were about to engage in a game of gotcha. I simply asked you to be crystal clear about your terms.

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All I want is an answer to my question, and as is plainly shown, you don't know it.

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Incorrect.What I plainly showed was that your question needs to be clarified.

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It doesn't matter what I mean by "random".

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It does when you bring it up. It's your argument. Therefore, you are the one that has to define your terms. If you don't care what "random" means, then simply talk about "mutation."Your other post seems to indicate some incredulity about the amount of mutation. You did say, after all: What is the point of this if not to eventually come around and say that the amount of mutation needed is so great that it couldn't have been random but had to be guided?

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Rrhain
WWJD? JWRTFM!

Rrhain-
You assume too much. This thread had the sole purpose of answering the single question: How much of evoloution is based off mutations? You automatically assumed, that, by asking a question that pushed the bounds of your beleif that I was planning on taking your queen with my knight.
Do you not realize that I registered with this site today? I have only found it today. I could not have the time to go through the site reading what everyone has to say on the multitude of subjects.
My use of "random" was purely to add to the sentence. But, to answer your question on the definition of "random", it would have to be this: without previous plan or prior concious thought. So no, todays biotechnological mutations would not be considered "random" in this context.Sylas-
What I ment by "how many mutations are passed to the offspring" was, how many were able to be passed on, as in the parents didn't die before reproducing, or the offspring were not killed by the mutations before being able to reproduce (you could throw some sterility stuff in there too if you want).I have a feeling I will end up checking that site out soon. (Not tonight though, too late and I have school tommarow; and more homework to do.)[This message has been edited by Rayne, 02-13-2004]

The answer is in the numbers I gave previously, but I'll try to spell it out more clearly, with a few more numbers of interest.What is passed on to you from your parents is a mix of their genomes. You get something like 3 billion base pairs from each parent, and this makes up your own diploid genome of something like 6 billion base pairs.Something like 5% of the human genome is made up of genes coding for proteins. (Ref: Human genome project) A smaller fraction will still have sequence significance; but not directly coding proteins; they may bind to other proteins and have a regulatory function, for example. But most of the genome is apparently "junk".Something like 64 (Drake's figure; this may be a bit low) new mutations show up in the germ-line of each human generation. This means that your own genome is 50% from Mum, 50% from Dad, and 0.000001% due to new mutations arising between you and your parents. Of those new mutations, around about 3 will be in coding DNA (5% of 64). Since the genetic code is redundant, a change to a codon might not actually change the amino acid sequence in expressed proteins; although it will give scope for more change as mutations accumulate in your own descendents.Perhaps as few as one or two mutations between you and your parents will actually make a difference in the proteins produced in your body. However, your children will add a few more, and so on, and over time your descendents will represent a range of diverse changes. This is the raw material of evolution.All this is "random", which means it occurs without any particular correlation for your own needs. You might have more, or less than these numbers; and the effects of any changes to your proteins might be neutral, or less often detrimental, or less often still beneficial. Detriment or benefit is a measure of the overall consequence for your reproductive fitness in your present environment; and can result from whole cascades of subtle effects.A lot of evolution is simply due to genetic drift, which refers to the accumulation of change that is neutral for fitness.The whole issue is complicated by other kinds of mutation, in which whole subsequences of DNA are cut and pasted from one place to another, or chromosomal changes (as in mice on Madeira, discussed in another thread). These are rather less frequent. Most evolutionary change seems to be simple point substitutions, or small insertions or deletions; and so the number quoted previously of 1 to 6 non-silent changes in coding DNA gives you the ball park figure.This is the background showing up in every new individual. It does not mean deformities, nor does it imply sterility. It is the normal background rate of mutation. Sure, no worries. But as I tried to hint earlier, you won't simply be able to look up answers quickly. What you need to do is continue learning the basics, both at school and as you do extended study for your own interest from other sources. It is well worth the effort, and I'm impressed that you are proposing to tackle the subject in more detail. You will find it very rewarding. I often wish I had done more biology in my own studies.Cheers -- Sylas

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Does anyone know how much of evoloution is based off random mutation? Like what percentage of changes are postulated to be from mutations?

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All of evolution is BASED on random mutaions. Natural selection then selects the best fit out of the mutants. Sciences experience with clones (genetically identical organisms, such as bacteria) seems to indicate that genes control phenotype and responses to environment. For instance, would you expect identical twins (genetic clones) to differ greatly from one another, physically? I would argue that they would not. I would argue that people with different genetic content would vary, and they do.So yes, evolution is based on mutations, with natural selection guiding the end result.

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Ok, I concede the point that all of evoloution is based off of mutations.

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AAAAAAAAAAAAAAAAAAARGGGGGHHH! Don't be so quick to accept everything people say... even Ned (though most of what he says is platinum).I firmly believe in evolution, and so far it appears that genetic mutation is an important mechanism of evolutionary change, with genes also being an excellent record of that change over time.HOWEVER, this does not mean that genetic mutation is the ONLY mechanism and so ALL of evolution is due to genetic mutation.One of the serious competitors to the genetic mutation theory of evolution, is symbiotic theory by Lynn Margulis. While it does not at to replace all genetic mutation as a source for evolutionary change, it shows that there are other mechanisms.In Symbiosis, different organisms can gradually become a necessary part of each other's lives and thus merge into a new "species". This has gotten some very good supporting evidence, and suggests that perhaps most of evolution from prokaryotes to eukaryotes was symbiosis rather than mutation. Margulis seems to make a solid point that this could also play a part in eukaryotes evolving into more complex plants and animals, and perhaps the evolution of complex animals into yet more complex species.Its those last two stages which are not very well defined though, and Ernst Mayr (in his forward to one of her books) seems to want to keep her enthusiasm in check on those possibilities.Here are three links that can help you with learning more about symbiosis: Lynn Margulis BioGood basic overview of SymbiosisMargulis's best book on the subject... Though the link is to amazon, I am not suggesting you buy it. You can probably find it in a library (that's where I found the copy I read). I just thought the link would give you a good pic of the cover and some info about the book.As for your question of what % are based on symbiosis vs genetic vs as yet possibly undiscovered mechanisms... I have no idea. Clearly if symbiosis is the major factor in evolution of simple organisms, while genetic is the major (or sole) mechanism in complex organisms, then the percentage would be skewed to symbiosis due the vast larger numbers of simple organisms. But I think that would be misleading.Frankly I think this will always remain guesswork.[This message has been edited by holmes, 02-13-2004]

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holmes
"...what a fool believes he sees, no wise man has the power to reason away.."(D. Bros)

Hey Rayne,
There is also a simple () calculation that you can make and it goes like this:2^n, where n=#of possible haplotypesHowever, the reality is that this number is not represented in the population at this time. Did they exist prior, but were selected against?...imo, quite likely. However, the symbiosis idea is interesting.