davidH

Ok, so getting back to the topic, lol!

Do you deny that the odds for evolution to have occurred to our level of complexity to be vast?

From everything that I have heard and read the odds do seem to be vast.

Mutations very very rarely are benefical mutations. Yet how many mutations are needed for us humans to arise from a simple structure? (not going into detail about how that simple structure first came to be).

ok, so you say that that is why it took millions of years for life to evolve - because of the odds that time limit is absolutely necessary otherwise it won't have been feasible.
But I question whether over even all these years whether it would have been possible of life to evolve.
Every textbook I have read states that mutations are very frequently fatal - I see that too in all the precautions that are taken in a nuclear power plant and those working with radioactive material.
Why all the precautions if mutations aren't extremely harmful?

I wonder if each of you here when you first accepted evolution had looked at the odds of it happening. Seriously though, is there any book from a mathematician's view of what the odds of life happening and evolving are?
That's one thing that when reading about evolution I have had trouble about. The odds seem so vast that I don't think it could have happened.
Even learning about the DNA and replication and mRNA and all that - it only brings even bigger doubts about evolution.
Cause there is always the chance of an organism having a benefical mutation and then getting a harmful one again which destroys the benefical mutation.

Are the odds vast? Even over the millions of years you give them?

Coragyps

I would say, as a non-expert in the field, that there is not yet sufficient data on our sample of one to calculate the odds of life, or intelligent life, arising on some particular planet. However, the probability of it happening on Earth is 1.0000. It already did.

daemon

The "odds" of evolution aren't really a very good argument. Take, for example, a deck of thoroughly shuffled cards. Lay them all out. The odds of any given configuration is approximately 1 in 8*10^67. Take two decks of cards. The odds of that configuration? Even longer, about 1 in 10^166. The argument from evolutionary "odds" is based on assuming that, since the odds of any given configuration is low, intervention is required to lower those odds. However, would you even argue that the configuration of two decks would have required a miracle to have the sequence it does? The odds of any given configuration are incredibly low, yet, through "chance," there it is.

This is only scratching the surface of the errors in this line of thought, however. How are you establishing the odds? Is it really as random as you think it is? To continue with my example, my calculations above only count if you have some truly random way of shuffling... the more information you have about the original state of things and the forces involved, the lower the odds we're concerned with become.

Finally, to turn the question on its head, what are the odds of, for example, a diety existing? Is it really relevant?
Billions upon billions.
There's a semantic shift here--you first off establish that most mutations are harmful, which I believe is correct, then jump to asking why precautions exist if all mutations aren't harmful. Though, really, what kind of question is this? Do you do things that have a good chance of hurting you when you could lower that chance?
I sincerely doubt it, and would be very skeptical of any such work. How would they be deriving their calculations? Where are they getting their data from? How reliable is it?

I do know various creationists have attempted to create such documents, but they are infamous for their lack of research, arbitrary assumptions which increase--never decrease--the odds, and outright misinformation. Such a track record does not reflect well on their efforts.
This is known as an argument from personal incredulity, which is, in essence, non sequitur if you're trying to claim it as some sort of evidence against evolution.

theyeti

It depends on what you mean. In general, no, I don't think that our level of compexity is unlikely. But that's just my intuition. I don't know that we can figure out at this time what the likelihood of the evolution of our level of complexity is. It may be likely, it may be unlikely, but either way it happened. We can see this from Earth histroy. Unless you're a YEC who denies Earth history, then the question is how it happened, not if.

You're going to have to support this assertion with something better than you've done so far. There is nothing in your facts nor your reasoning that would convince me.

How many times must we go over this? Mutations are only rare in well adapted organisms. Those that are not well adapted will have frequent beneficial mutations. This is why the rate of evolution is faster after global climate change and mass extinction. Going back to our example of duplicated genes and subfunctionalization, a new duplicate that is subfuntionalized for a given activity will generally be inefficient to start out with. So in this case the chances of a beneficial mutation are quite high. But once it's reached a local optimum, no mutations, exept for very drastic ones, will have a chance of being beneficial. Claiming that beneficial mutations are rare in highly adapted proteins tell us exactly what we should expect if evolution by natural selection is true. But the fact that relatively few of them are at a global optimum is also what we expect.

That it took millions of years is an empirical fact. We know it's true from Earth history. You can deny evolution when looking at Earth history, but it requires some serious mental gymnastics. So again, the question isn't really
"if" but rather "how". Dawinian evolution has the added bonus that it makes us expect gradual evolution, at least on a geological time scale. Thus it fits quite well with what we observe.

Incidentally David, what is your explanation for the vast amounts of time involved in Earth history that preceded ourselves? How do you explain the presence of "precursors" to ourselves, like primitive hominids, that were preceded by primitive primates, who themselves were preceded by primitive mammals, and so on? Coincidence? Deceptive deity?

No, most mutations are neutral or weakly harmful. A small number of them are beneficial, even in well adapted organisms. The number that are fatal is relatively small. Nearly everyone is born with at least a few new mutations. The mutation rate per gamete per generation is 7.73 according to <a href="http://www.graylab.ac.uk/cgi-bin/omd?query=gamete" target="_blank">this page</a>. I don't know how you got your earlier number, but it's way off -- you probably saw the mutation rate per gene. So this means that on average you will have around 14 point mutations that distinguish you from your parents. And that doesn't even take into account other forms of mutation, like duplication (which are certainly more rare). Could they be fatal? Sure they could, but the fact you're here suggests that they're not. Gametes die all the time, as do zygotes, fetuses, and sometimes young children. That's the whole point of natural selection.

Nuclear power plants, at least in the reactor cores, put out enough radiation to give you a lethal dose within milliseconds. That's why the precautions.

There is no legitimate calculation on "the odds of it happening". Such a calculation would depend on the particular model that you're looking at. If that model is too unlikely, then you have to scrap it for a more likely model. Our currently model of mutation and selection works quite well, though there are obvious details left to be filled in.

If you want a book by a creationist mathematician that isn't total garbage, look for something by Bill Dembski. But he hasn't been able to produce a calculation, even after promising his critics that he would, and he's far more sophisticated than your typical creationist. And his critics are quick to point out that such a calculation is only meaningful with respect to a particular chance hypothesis, not all possible chance hypotheses.

David! Pray tell what odds?! Unless you present us with a detailed and accurate calculation, then this is nothing more than an argument from incredulity. Even if you could do such a calculation, all you would have shown is that a particular model is wrong (or unlikely). For example, you might show that mutation and selction won't work by themselves, but you would not have disproven evolution. You still have to contend with all of the evidence that it did happen before you can convince someone that it didn't.

What do you make of things like the fossil record, nested hierarchies, bigeography, molecular phylogenetics including those pseudognes that we've been going over, and so on? How would you explain these except through common descent? I don't really entertain people who claim that airplanes can't fly when I see them flying.



Yep, this can happen. But there's this thing called natural selection that tends to preserve good mutations and weed out bad ones. Most people take it for granted, but we have it good these days. Most species have tremendously high morality rates. For animals like insects, it's something like 99% that die before reproducing. Bad genes get weeded out very quickly, and good ones are strongly preserved, even if they give only a slight advantage.

.

You simply don't give scientists enough credit. They have taken the mutation rates and observed rates of change into consideration. They are more than enough to account for evolutionary change seen throughout geological time.

theyeti

[ February 04, 2002: Message edited by: theyeti ]</p>

scigirl

David,

Here's some actual data on the time issue of evolution:While I was reading the book, Origin and Evolution of the Vertebrate Immune System, I came across an interesting passage in Chapter 1:
I did some calculations based on these numbers. This means that there was one rearrangement every 714,000 years. That doesn't seem too unreasonable, does it, especially considering that mice, and presumably many of the other species, have a generation time of less than a year.

Also David, I don't think we really know that much about the rates of those other types of mutations that could cause evolution, such as gene duplications, genome duplications, integration of viral genomes, and jumping genes.

I agree with the yeti. All the circumstantial evidence points to evolution, and against YEC. Just like in a murder trial--the weapon was there, the murder had a motive. . .

Now we are trying to figure out how. And it is a very exciting field, and time to be studying evolution.

scigirl

Kevin Dorner

davidH: I strongly suggest you read Richard Dawkins' Climbing Mount Improbable which discusses this very thing: the probabilities.

Usually I find that his prose, while informative, is rather mild and I don't find myself overly praising it while reading it. But that all changed with chapter 5: The Forty-Fold Path To Enlightenment. It is the best piece of writing about evolutionary biology for the general reader that I have read thus far, that comes to mind at least... Given that its subject is the evolution of eyes, it has to be.

[ February 04, 2002: Message edited by: Kevin Dorner ]</p>

scigirl

One more piece of data about the "time" factor, from The Blind Watchmaker by Dawkins:

This was a computer model of eye evolution.
And so on. With their conservative numbers, they approximated that the amount of time these changes would take was fewer than four hundred thousand generations. For simpler organisms, "it seems that it would take less than half a million years to evolve a good camera eye."

More realistically, the time required is even shorter, if you do allow for a higher heritable percent, and you allow for simultaneous changes.

scigirl

davidH

"I would say, as a non-expert in the field, that there is not yet sufficient data on our sample of one to calculate the odds of life, or intelligent life, arising on some particular planet. However, the probability of it happening on Earth is 1.0000. It already did."

I'd just want to point out to whoever wrote this that this is circular reasoning at its worst, I too could say that because there is life on this planet the probablity of there being a God is 100%. But I don't because it doesn't prove anything.

You ask me to show you my reasoning for the odds being vast.

Yeah, but there has to be a configuration, the odds of their being a configuration are 100%. However as far as I have understood evolution, there didn't have to be a "configuration" when life began. There could have been no life as we see in many planets that are similar to our own in distances from a sun like ours.

You see if you think about it the odds of mutations occurring in an exact place in the DNA so they aren't harmful, then more mutations occurring in the same place again so that a sufficient lenght of benefical DNA is formed that produces a protein that somehow helps a cell, without during this time another mutation occurring that damages the cell and causes natural selection to remove it, what are the odds?

There can't have been (at that early stage) any proteins that weren't already essential that could have been altered to produce another one.
Even if there was duplication - it is potentially fatal too. (read in Biology Principles and Processes).

"Yet another abnormality occurs when a section of chromosome replicates so that a set of genes is repeated; this is duplicationn. Again, duplication is frequently harmful. However on occasions it may be accounted for."

I put the others down too.

"This is called deletion and, as it leads to the absence of certain genes, it can have a profound effect on the developement of an organism. In fact all but the shortest deletions are usually fatal."

I can see why this is so. you remove one, then all the rest to a certain point is completely messed up.

Translocation may benefit an organism but since no bases are added or lost it on its own couldn't lead to major changes.

Addition is as bad as deletion, the changing of bases will ruin the triplet but couldn't on its own cause a major benefit, there would probably have to be quite a few more changes too.

And yet you have said

and yet another of you agrees with me;

Now, what type of mutations are the most common to organisms?
Even if the mutation is weakly harmful, won't that put the organism at a disadvantage so it will probably be removed by natural selection?

This experiment is flawed and cannot be compared to evolution.
A computer program is complex and consists of orders and rules - there's nothing random about that.
It doesn't even come near the complexity of living organisms, you see when the program is ordered to mutate (or whatever) the resulting program would still have to be a combination of those same instructions - the resulting "eye" didn't display any capability that the original program didn't have.
The program would have to invent new instructions which I assume is what would have to be need to illustrate "upward" evolution.
Infact thinking about it - wouldn't this actually support a creator?
That a program first has to be programmed with a set of instructions and rules that it must stick to before it will evolve in the way it would have had to.
An interesting thought that.

Ah, the murder had a motive.....What motive is there in evolution? (not serious, lol)

Circumstantial evidience.......
What do you mean by this? Evidience not based on scientific means but directly on the circumstances you find it in?

You say that life started millions and millions of years ago.

What evidience do you have on this (no circular evidience please ie. evolution had to have taken that long therefore life must have started that long ago).

(I always seem to find that for every answer I find, many more questions arise!I suppose we can never know everything.)

scigirl

DavidH,

You can't be serious. You want evidence of descent with modification? Read ANYTHING from talkorigins.

What I meant by "circumstantial," is that the evidence points to descent, but does not necessarily prove with 100% assurance that evolution happened.

Just like finding a motive, weapon, blood, etc does not prove with 100% assurance that "Ray killed Steve." Each piece of evidence individually may have another explanation (which no doubt the defense attorney will argue).

So because we can't be 100% sure, should we stop trying to prosecute murderers? I hope not! Instead, we look at the entire picture, and convict on "beyond a reasonable doubt."

We will never be able to say with 100% proof that X evolved into Y. What we can do though, is look at the patterns of all organisms on the earth. Is the abundant fossil evidence consistent with YEC? No way. Is it consistent with evolution? Yes. Every time a fossil is discovered, the same question is asked. And the answer has been "it supports evolution" for over 100 years.

Evidence for an old earth--learn anything about physics, and radioactive decay. This is not circumstantial data, it is hard-core math proofs. The earth is over 4 billion years old, not 6000. This is a mathematical fact. Again, read talkorigins, or other threads around here.

Now, scientists have proven beyond a reasonable doubt that descent with modification did occur. So they are trying to figure out how using genetics. If they are wrong, than they should find evidence that genetic phenomenon are insufficient to cause evolution--both in theory (the eye example) and in practice.

What have they found so far--that genetic mechanisms do seem to be sufficient for causing evolution.

I noticed you critiqued my eye example, but not the mouse-human data. Any thoughts there, DavidH?

scigirl

theyeti

I would like you to list these planets and tell us where they can be found.

Quote:

You see if you think about it the odds of mutations occurring in an exact place in the DNA so they aren't harmful, then more mutations occurring in the same place again so that a sufficient lenght of benefical DNA is formed that produces a protein that somehow helps a cell, without during this time another mutation occurring that damages the cell and causes natural selection to remove it, what are the odds?

This all sounds very confused and I'm getting the impression that you're not listening very well. The odds DEPEND ON THE ENVIRONMENT. In the proper environment (where members of a population are not highly adapted), the odds are quite good. This is especially true considering that such a mutation needs to occur in only one organism out of many. Then sexual recombination can allow several such beneficial mutants to be brought together; it also prevents any one mutant from being stuck permanently with a bunch of bad genes.

David, this is talking about large chromosomal duplications, not individual gene duplications. Try reading the earlier stuff we posted on that. Gene duplications are very rarely fatal, and very often helpful. Many genes exist in large gene "families", where one can actually trace the history of duplication and divergence from an ancestral gene. The globin family is one such example.

Also, "in that early stage" as you talk about, things like whole genome duplications would have probably been more easily tolerated, since there was less complexity in the system.

Here are some additional references on gene duplication. Even if you don't read them (which you won't) at least looking at the titles should give you an idea of the importance of duplication.

Begun DJ., Origin and evolution of a new gene descended from alcohol dehydrogenase in Drosophila. Genetics 1997 Feb;145(2):375-82

A Amador and E Juan, Nonfixed duplication containing the Adh gene and a truncated form of the Adhr gene in the Drosophila funebris species group: different modes of evolution of Adh relative to Adhr in Drosophila. Mol Biol Evol 16: 1439-1456.

Inoue K, Dewar K, Katsanis N, Reiter LT, Lander ES, Devon KL, Wyman DW, Lupski JR, Birren B., The 1.4-Mb CMT1A duplication/HNPP deletion genomic region reveals unique genome architectural features and provides insights into the recent evolution of new genes. Genome Res 2001 Jun;11(6):1018-33.

Brown CJ, Todd KM, Rosenzweig RF (1998) Multiple duplications of yeast hexose transport genes in response to selection in a glucose-limited environment. Mol Biol Evol 1998 Aug;15(8):931-42 Nature 387, 708 - 713 (1997)

Hoshino A, Johzuka-Hisatomi Y, Iida S., Gene duplication and mobile genetic elements in the morning glories. Gene 2001 Mar 7;265(1-2):1-10.

Araki H, Inomata N, Yamazaki T., Molecular evolution of duplicated amylase gene regions in Drosophila melanogaster: evidence of positive selection in the coding regions and selective constraints in the cis-regulatory regions. Genetics 2001 Feb;157(2):667-77

O'Malley BW, Stein JP, Means AR., The evolution of a complex eucaryotic gene. Metabolism 1982 Jul;31(7):646-53.

Wagner A., Birth and death of duplicated genes in completely sequenced eukaryotes. Trends Genet 2001 May;17(5):237-9.

Nadeau JH, Sankoff D., Comparable rates of gene loss and functional divergence after genome duplications early in vertebrate evolution. Genetics 1997 Nov;147(3):1259-66.

Force A, Lynch M, Pickett FB, Amores A, Yan YL, Postlethwait J., Preservation of duplicate genes by complementary, degenerative mutations. Genetics 1999 Apr;151(4):1531-45.

Soltis DE, Soltis PS., Polyploidy: recurrent formation and genome evolution. TRENDS IN ECOLOGY AND EVOLUTION 1999 Sep;14(9):348-352.

Taylor JS, Van de Peer Y, Meyer A., Genome duplication, divergent resolution and speciation. Trends Genet 2001 Jun;17(6):299-301.

Courseaux A, Nahon JL., Birth of two chimeric genes in the Hominidae lineage. Science 2001 Feb 16;291(5507):1293-7.

Jelesko JG, Harper R, Furuya M, Gruissem W., Rare germinal unequal crossing-over leading to recombinant gene formation and gene duplication in Arabidopsis thaliana. Proc Natl Acad Sci U S A 1999 Aug 31;96(18):10302-7.

That last one is particularly interesting. It shows that the rate of duplication and exon shuffling is 3 e-6. That's about 3 for every million. Not a lot, but in a population of several millions, there will be many in each generation. So this rate is more than enough to account for the observed numbers of genes, even without genome duplications. Of course, this study was done on a plant species, and I don't know if the animal value is comparable.

Ding ding ding! Give that man a prize! Yes, that's what natural selection does. It removes harmful mutations, even the weakly harmful ones, given tight enough selective pressures. That's why what we are left with is organisms that either have neutral or beneficial mutations. Then they reproduce like mad and pretty soon all members of a populatoin have those beneficial mutations. This is oversimplified, but it's the general idea behind natural selection's ability to generate more adaptive organisms. The fact that harmful mutations are more frequent doesn't matter.

Quote:

This experiment is flawed and cannot be compared to evolution. A computer program is complex and consists of orders and rules - there's nothing random about that.

Evolution is not random either, David. It consists of a very non-random component, natural selection. In this simulation being referred to, the "mutation" aspect was indeed random -- computers are capable of that you know. The fact that they used a computer is irrelevant; what matters is if their simulation was a reasonable model of what we think goes on in nature. Now there may be some reasons to think that it's not, but the fact that they used a computer is not one of them.