|
Register | Sign In |
|
QuickSearch
EvC Forum active members: 64 (9163 total) |
| |
ChatGPT | |
Total: 916,419 Year: 3,676/9,624 Month: 547/974 Week: 160/276 Day: 34/23 Hour: 1/3 |
Thread ▼ Details |
|
Thread Info
|
|
|
Author | Topic: How long does it take to evolve? | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Lamden Junior Member (Idle past 2417 days) Posts: 25 From: Lakewood Joined:
|
I am curious if anyone could help me calculate this:
Let's ignore the enigma of abiogenesis for the sake of this discussion. Ditto for the complexity conundrum which has already been discussed at length on this forum- assume every mutation would happen exactly as needed, in perfect order. I would like to know, approximately how many mutations would theoretically be needed to transform the most basic form of life into a human being? I know it is not easy to count, but I am looking for an educated guess. If DNA alone is 6 ft of microscopic code, that must been quite a bit of evolving right there! Then, let us assume a uniform mutation rate of .003 mutations per cell generation ( I lifted that number from wikipedia- please feel free to point out if I have used it incorrectly). Next, we figure that the life span of a cell is somewhere between a week and a year - (another tidbit I picked up online at biology.about.com ; again, I welcome corrections as needed). Let us assume a uniform rate of 1 month per generation. Once we know the number of mutations needed, the mutation rate , and lifespan, how long would a best-case-scenario human evolution have taken? I think that this is a crucial starting point, and would much appreciate if someone could help provide a layman like myself some light on the subject. Edited by Adminnemooseus, : Put in blank lines.
|
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Adminnemooseus Administrator Posts: 3974 Joined: |
Thread copied here from the How long does it take to evolve? thread in the Proposed New Topics forum.
|
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Dr Adequate Member (Idle past 305 days) Posts: 16113 Joined: |
Hello and welcome. That's an interesting question. The answer, I'm afraid, is not going to be that simple. The figure you have from Wikipedia is, I presume, the rate of single nucleotide substitutions. But there's lots of other ways the genome can change, and these have to be taken into account. For example, about 21% of the human genome consists of long interspersed nuclear elements. Single nucleotide substitution isn't and can't be responsible for these: Wikipedia says:
LINE elements propagate by a so-called target primed reverse transcription mechanism. This mechanism was first described for the R2 element from Bombyx mori: A specific nick on one of the DNA strands at the target site is generated by the endonuclease encoded by the R2 element. Thus, a 3'OH group is freed for the R2 reverse transcriptase to prime reverse transcription of the LINE RNA transcript. Following the reverse transcription the target strand is cleaved and the thus created cDNA integrated. So, at what rate does that mechanism produce copies? I don't know. I don't know if anyone knows. But stuff like that would have to be considered in order to answer your question: it would make no sense to treat LINEs as though they were produced by a series of single nucleotide substitutions when we know for a fact that they're not. Then we should consider SINEs. And gene duplication ... So, there's no easy answer.
|
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
AZPaul3 Member Posts: 8527 From: Phoenix Joined: Member Rating: 5.2
|
As Dr. A has already pointed out mutation rates depend on what mutation type is being considered. Another thing is that evolution, even assuming some useful mutation just shows up when needed, doesn't work in that strictly linear a fashion.
If the goal is to determine how many mutations it takes to go from the simplest single cell progenitor to human then you have to make so many assumptions on so many processes that, ultimately, any number you come up with will have error bars larger than can be useful. You will have learned nothing. If the goal is, as you say,
... how long would a best-case-scenario human evolution have taken? then we already have that answer. Not a best-case-scenario but an only-case-scenario. 3.8 billion years give or take a couple hundred million years or so. The earliest life on this planet is dated around 3.8 billion years ago. From then until humans, about 200,000 years ago. So pick a number from 4.0 to 3.5 billion years and that's the best you are going to get. And because I'm feeling impish I'll add this. We live in a probabilistic universe, not a deterministic one. If you back up to 3.8+- billion years ago and let the whole scene run unhampered yet again you will most probably not have humans. Ever.
|
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
nwr Member Posts: 6409 From: Geneva, Illinois Joined: Member Rating: 5.3 |
I would like to know, approximately how many mutations would theoretically be needed to transform the most basic form of life into a human being? Personally, I wouldn't even try to guess. However, I was just reading a blog post by Larry Moran, and noticed this paragraph:
quote: So it seems that Larry's answer is 22 million. Larry Moran is a biochemist at U. Toronto, and I have come to respect his views on evolution related topics.Fundamentalism - the anti-American, anti-Christian branch of American Christianity
|
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Dr Adequate Member (Idle past 305 days) Posts: 16113 Joined: |
Yes, but that's not starting with the simplest organism, is it?
|
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
AZPaul3 Member Posts: 8527 From: Phoenix Joined: Member Rating: 5.2 |
Let's see:
22,000,000 mutations in 6,000,000 years, that's 3.67 mutations per year times 3,800,000,000 years gives us 13,946,000,000 mutations start to finish divided by 20,939,940 species involved equals 666. uhh
|
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
dwise1 Member Posts: 5948 Joined: Member Rating: 5.5
|
In your model, you start with single-celled asexually-reproducing organisms and then move on through many levels of sexually-reproducing animals. Unfortunately, your model does not take that into account.
Your model is based on mutation rates in body cells (AKA somatic cells). But in sexually reproducing animals, such mutations are of no interest in evolution. Rather, the mutations that are of interest are the ones occurring in germ cells (AKA gametes), which is to say in the sperm and eggs. When body cells mutate, those changes disappear when that body dies. When gametes mutate, those changes are passed on to other bodies -- ie, to the offspring of the body in which the gametes had mutated -- and then have a chance of being passed on further to future generations. Your model's use of somatic cell mutation rates and cell replacement times may be useful when dealing with the asexual organisms which use fission and budding and the like, but as soon as you start dealing with sexual reproduction then the generational time changes to that of the organism (eg, about 14 years for humans, a year for dogs). Your calculations would need to take that into account.
|
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Lamden Junior Member (Idle past 2417 days) Posts: 25 From: Lakewood Joined: |
And responding with intelligent answers.
The reason I think this discussion is so important , is because I have seen far too much irrelevance from both sides of the c/e debate. In order for evolution to win this debate, or at least this arm of it , they don't need to prove that evolution happened. They just need to prove that it COULD happen. And in order for the creationists to win, they don't have to prove that creation happened. They just have to prove that e/v could NOT happen. So i figger, if we could figure out a best case scenario, and there still is not enough time to evolve, we would have ruled out e/v. Unfortunately, it seems as though no one has no idea how to figure out, a) how many of the relevant mutations are needed. b) how long is the regeneration cycle c) what percentage of the relevant mutations are thought to be beneficial d) how long should it take for each beneficial stage to dominate its population e) How many of the beneficial mutations will be thwarted by subsequent fatal mutations I could start puking out guesses for every one of these numbers, but unless someone can procure some meaningful inputs, I fear that neither camp will be very much impressed from a calculation based on contrived numbers. I do, however, believe, that an inability to provide any estimate whatsoever as to the likelihood or possibility of evolution occurring is a strike against the theory. Perhaps not a fatal blow, but a serious shortfall .
|
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Coyote Member (Idle past 2127 days) Posts: 6117 Joined:
|
I do, however, believe, that an inability to provide any estimate whatsoever as to the likelihood or possibility of evolution occurring is a strike against the theory. Perhaps not a fatal blow, but a serious shortfall . There is quite a difference between being able to observe evolution via the evidence of fossils, genetics, laboratory experiments, and real life observations and being able to explain all the fine points of how it occurred. You can't erase all of the evidence for evolution because of not knowing the exact rate of mutation for 3.8 billion years, though I'm sure creationists would like to do so.Religious belief does not constitute scientific evidence, nor does it convey scientific knowledge. Belief gets in the way of learning--Robert A. Heinlein How can I possibly put a new idea into your heads, if I do not first remove your delusions?--Robert A. Heinlein It's not what we don't know that hurts, it's what we know that ain't so--Will Rogers If I am entitled to something, someone else is obliged to pay--Jerry Pournelle If a religion's teachings are true, then it should have nothing to fear from science...--dwise1 "Multiculturalism" demands that the US be tolerant of everything except its own past, culture, traditions, and identity.
|
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
subbie Member (Idle past 1276 days) Posts: 3509 Joined:
|
Lamden writes: The reason I think this discussion is so important , is because I have seen far too much irrelevance from both sides of the c/e debate. I'd love to see some examples of what you would consider "irrelevance" from the scientific side of the debate.
Lamden writes: In order for evolution to win this debate, or at least this arm of it , they don't need to prove that evolution happened. First of all, science isn't about proving anything. Science is about coming up with the best explanations for the evidence we have to date. Science never proves despite what you might hear from the popular media. Second, science has already won the debate, over 100 years ago. There is no scientific debate to win. All the evidence supports the ToE, none of the evidence supports creationism in any of its guises. We don't need to know the specifics of every step along the way, nor do we need a mathematical calculation to establish the possibility of something that all the evidence shows actually happened. I strongly suspect you have some unstated, ulterior motive for your questions.Ridicule is the only weapon which can be used against unintelligible propositions. -- Thomas Jefferson We see monsters where science shows us windmills. -- Phat It has always struck me as odd that fundies devote so much time and effort into trying to find a naturalistic explanation for their mythical flood, while looking for magical explanations for things that actually happened. -- Dr. Adequate Howling about evidence is a conversation stopper, and it never stops to think if the claim could possibly be true -- foreveryoung
|
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Tanypteryx Member Posts: 4411 From: Oregon, USA Joined: Member Rating: 5.4
|
In order for evolution to win this debate, or at least this arm of it , they don't need to prove that evolution happened. They just need to prove that it COULD happen. As has already been pointed out, science is not about proving anything, it is about a coherent explanation of all the evidence. So far, all the evidence and observations from multiple branches of science support the theory of evolution. No evidence refutes it. Life evolves and all the evidence shows it.
And in order for the creationists to win, they don't have to prove that creation happened. They just have to prove that e/v could NOT happen. Sorry, but this is not true. Whether or not evolution is true says nothing about the validity of creation.
So i figger, if we could figure out a best case scenario, and there still is not enough time to evolve, we would have ruled out e/v. Well, 3.8 billion years is a long time, and complex multicellular life has been around for about 0.6 billion years. In that time, millions of species have evolved and gone extinct.
Unfortunately, it seems as though no one has no idea how to figure out, a) how many of the relevant mutations are needed. b) how long is the regeneration cycle c) what percentage of the relevant mutations are thought to be beneficial d) how long should it take for each beneficial stage to dominate its population e) How many of the beneficial mutations will be thwarted by subsequent fatal mutations a) What is a relevant mutation? b) What is a regeneration cycle? c) You are asking the same question as a. d) What do you mean by beneficial stage? And why does it need to dominate the population? e) I have no idea what you are asking here, but all fatal mutations cause death.
I could start puking out guesses for every one of these numbers, but unless someone can procure some meaningful inputs, I fear that neither camp will be very much impressed from a calculation based on contrived numbers. You are correct. The numbers you want will only be guesses, there is no calculation involved. What would be the point in trying to figure out these numbers? What could that possibly tell you? We have seen numerous calculations of supposed odds against various aspects of evolution happening. They are all based on a total lack in understanding the concept of probability and an even larger misunderstanding of genetics and evolution.
I do, however, believe, that an inability to provide any estimate whatsoever as to the likelihood or possibility of evolution occurring is a strike against the theory. Perhaps not a fatal blow, but a serious shortfall . The likelihood of evolution happening calculates to exactly 1, so fatal blow averted. What if Eleanor Roosevelt had wings? -- Monty Python One important characteristic of a theory is that is has survived repeated attempts to falsify it. Contrary to your understanding, all available evidence confirms it. --Subbie If evolution is shown to be false, it will be at the hands of things that are true, not made up. --percy
|
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
dwise1 Member Posts: 5948 Joined: Member Rating: 5.5
|
Lamden:
I started studying "creation science" in 1981 and began discussing it on-line with creationists around 1986. Before then, in the early 1970's, I was a kind of "fellow traveller" of Christian fundamentalism during which time I learned a lot about their proselytizing methods and training materials -- it was during that time that I first encountered young-earth creationism. So you might say that I've been around the park more than a few times and I have acquired a nose for certain smells. What I am smelling here is a creationist using a not-so-common ploy: a reasonable person attempting a reasonable discussion in which both sides are weighed fairly and without him taking either side. Of course, when we do engage in that discussion (as I always try to do, much to the chagrin of the creationist) we quickly discover that "reasonable person" as being a creationist in sheep's clothing who's taking the standard course of attacking evolution in order to "prove" creation by process of elimination as per their Two-Model Approach, a false dichotomy intended to deceive the courts and the public. Like I said, I've been around the park more than a few times and I have seen many things. That is what I am smelling from you. Of course, I could be wrong, but your next actions will determine that. And even if I am right, that does not automatically mean that you might not be a reasonable person after all. Nor that we could not have a reasonable discussion after all. Do please stay and let us have a reasonable discussion.
|
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Dr Adequate Member (Idle past 305 days) Posts: 16113 Joined: |
I do, however, believe, that an inability to provide any estimate whatsoever as to the likelihood or possibility of evolution occurring is a strike against the theory. Perhaps not a fatal blow, but a serious shortfall . You did not ask about "the likelihood or possibility of evolution occurring". You asked how long it would take to get from a simple organism to humans. You are now lying to us about the topic of your own thread, which you started, which we can all read, in what is only your second post ever on this forum. Are you trying to set some sort of a record?
|
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
RAZD Member (Idle past 1426 days) Posts: 20714 From: the other end of the sidewalk Joined:
|
Welcome to the fray, Lamden
I do, however, believe, that an inability to provide any estimate whatsoever as to the likelihood or possibility of evolution occurring is a strike against the theory. Perhaps not a fatal blow, but a serious shortfall Not really a valid conclusion: if you don't know then you can't know or even suppose what the answer is. But maybe if we look at part of the picture and see what some of the evidence shows, we can get a better idea: Just a moment...
quote: So that's about 40 million years to develop from a mouse to the largest known land animal.
quote: Sticking just to elephants then ...
quote: So the largest Elephant took longer to reach the same approximate mass as the giant rhino, but still had time left over ... and the time to reach the size of a modern elephant would be less. With 70 million years available for such a transition to occur, not all the time was used to increase size. Also note that the growth in size is not necessary in every generation, so the fastest observed growth rate would necessarily be less than the maximum possible growth rate if evolution focused solely on size. From this I would conclude that the time available exceeds the time necessary in a minimum step-by-step track. And I see no reason not to expect a similar excess of time to reach any possible evolutionary position in the fossil and living organism catalog. Evolution is a drunken walk not a fast-track trade deal, it doesn't know where it is going or when it will get there. It certainly is not interested in any "goals" you may think are important. Enjoy
... as you are new here, some posting tips: type [qs]quotes are easy[/qs] and it becomes:
quotes are easy and you can type [qs=RAZD]quotes are easy[/qs] and it becomes:
RAZD writes: quotes are easy or type [quote]quotes are easy[/quote] and it becomes:
quote: also check out (help) links on any formatting questions when in the reply window. For other formatting tips see Posting TipsFor a quick overview see EvC Forum Primer If you have problems with replies see Report Discussion Problems Here 3.0 by our ability to understand Rebel☮American☆Zen☯Deist ... to learn ... to think ... to live ... to laugh ... to share. Join the effort to solve medical problems, AIDS/HIV, Cancer and more with Team EvC! (click)
|
|
|
Do Nothing Button
Copyright 2001-2023 by EvC Forum, All Rights Reserved
Version 4.2
Innovative software from Qwixotic © 2024