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Does evolution happen by chance?

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Description: Is evolution directed or not
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mentari
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« on: March 31, 2009, 11:47:28 AM »

I hope this is not a stupid question because many people say that me being  YEC fundamentalist Christian is actually not very bright. So perhaps somebody can help me out:

Does evolution happen by chance ?
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Mefiante
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« Reply #1 on: March 31, 2009, 13:29:36 PM »

Does evolution happen by chance ?
You need to be considerably more specific about what exactly you mean with “by chance.”  If you mean, for example, that somewhere a lizard suddenly grows a beak, some feathers and a pair of wings, and thus “by chance” turns into a bird, then that is a creationist straw man, and a very silly one at that.  In fact, if such a thing were to be observed, it would refute evolution.

Strictly speaking, evolution is the study of gene and allele frequencies.  This means that evolution concerns itself with how certain genes (or alleles) become abundant or scarce, and the factors that play a role.

Evolution has two main drivers.  First, there is “a source of diverse raw genetic material” carried by the totality of organisms belonging to a particular species.  Second, there is the collection of environmental factors that determine which of those organisms are more suited to their living conditions and are better able to produce offspring.  The better-adapted ones will survive and procreate preferentially, and so their genes will become (relatively) more abundant, while the less successful ones will tend to become scarcer.

It should be noted that the process is statistical, not strictly deterministic: any one poorly adapted specimen could outlive and outbreed any one well-adapted one but, overall, the well-adapted ones will outlive and outbreed the less well-adapted ones.  This part of evolution is what is called “natural selection.”

The “raw genetic material” mentioned earlier varies among all the individual organisms of a species.  This variation has an element of chance (or randomness) to it insofar as specific genetic differences between individuals are for all intents and purposes unpredictable.  The genetic makeup of a specific organism is largely determined by that of its progenitors (parental line) but not entirely.  Copy errors and mutations are chance occurrences that keep feeding (and possibly extending) the range of genetic diversity, which the environment then filters for suitability.

Many such variations are largely neutral in terms of their effect on survivability.  By pure chance, some genes will be more and some less abundant from generation to generation, just as you are unlikely to find exactly the same number of heads and tails in a long series of tosses of a fair coin.  This accounts for so-called “genetic drift” where the genome of a population changes over time.  However, sometimes a sudden change in the environment (which, again, for all practical purposes is a random event) can make one of these variants more successful than the others and so ensure its proliferation.

Therefore, the answer to the question is that, while evolution has some elements of chance to it, it does not produce haphazard results basically because less suitable variations are soon eliminated.

'Luthon64
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bluegray
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« Reply #2 on: March 31, 2009, 17:25:15 PM »

To that excellent answer, I can only add this link: http://en.wikipedia.org/wiki/Weasel_program Wink
And maybe another short summary: Variation in genes is random, natural selection is not.
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mentari
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« Reply #3 on: March 31, 2009, 20:50:39 PM »

You need to be considerably more specific about what exactly you mean with “by chance.”  If you mean, for example, that somewhere a lizard suddenly grows a beak, some feathers and a pair of wings, and thus “by chance” turns into a bird, then that is a creationist straw man, and a very silly one at that.  In fact, if such a thing were to be observed, it would refute evolution.

Depends what you define as "evolution". I understand it to mean the transmutation of species.
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scienceteacheragain
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« Reply #4 on: March 31, 2009, 20:58:27 PM »

There is no need to add to Luthon's excellent description  Smiley
However, I would like to point out a discrepency between the title of this post and the description.  The most simple answer to the question: "Does evolution happen by chance" is no, but it does not follow that it is "directed" either.  There is no dichotomy there, not even a false one.  
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« Reply #5 on: March 31, 2009, 21:06:41 PM »

Does evolution happen by chance ?

I agree with bluegray V, good answer 'Luthon64. I would like to suggest an alternative answer - No.  Wink

This is what Richard Dawkins said in an interview -
You said in a recent speech that design was not the only alternative to chance. A lot of people think that evolution is all about random chance.

That's ludicrous. That's ridiculous. Mutation is random in the sense that it's not anticipatory of what's needed. Natural selection is anything but random. Natural selection is a guided process, guided not by any higher power, but simply by which genes survive and which genes don't survive. That's a non-random process. The animals that are best at whatever they do-hunting, flying, fishing, swimming, digging-whatever the species does, the individuals that are best at it are the ones that pass on the genes. It's because of this non-random process that lions are so good at hunting, antelopes so good at running away from lions, and fish are so good at swimming.
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mentari
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« Reply #6 on: March 31, 2009, 21:16:45 PM »

There is no need to add to Luthon's excellent description  Smiley
However, I would like to point out a discrepency between the title of this post and the description.  The most simple answer to the question: "Does evolution happen by chance" is no, but it does not follow that it is "directed" either.  There is no dichotomy there, not even a false one.  

Again it depends what concept you as signal sender is sending to me signal receiver using the symbol string 'evolution' - what protocol are you using.
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scienceteacheragain
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« Reply #7 on: March 31, 2009, 22:01:50 PM »

Since the question is yours, what do you mean by evolution?
Using the simple definition you offered above, the answer is still "no".  Additionally, I can't think of any variation or nuance of the definition of evolution in Biology that would change my contention that "by chance" and "directed" do not establish a dichotomy.
 The definition of "directed" possibly could, but that is a seperate issue and would depend on why someone takes issue with it (I only picked up on it when I re-read my post, but I suspect Luthon would have called me on it if she were online) Grin.
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« Reply #8 on: March 31, 2009, 22:32:11 PM »

Depends what you define as "evolution". I understand it to mean the transmutation of species.
Have you actually read my reply?  It includes a definition of what evolution is.  And the phrase “transmutation of species” is a dead giveaway.  Speciation is, considered from the gene/allele frequency perspective, actually incidental, a mere by-product of the influence of the environment on genetic interactions.  It is why Richard Dawkins wrote of The Selfish Gene.



Again it depends what concept you as signal sender is sending to me signal receiver using the symbol string 'evolution' - what protocol are you using.
You’re dodging the issue here, especially considering that you have given your understanding of evolution in the post immediately before the one cited above.

You’ve been here before using a slightly different name, haven’t you?  And before?  And before?

'Luthon64
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mentari
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« Reply #9 on: April 01, 2009, 10:39:34 AM »


Strictly speaking, evolution is the study of gene and allele frequencies.  This means that evolution concerns itself with how certain genes (or alleles) become abundant or scarce, and the factors that play a role.


Wikipedia:
In biology, evolution is change in the genetic material of a population of organisms from one generation to the next. Though the changes produced in any one generation are small, differences accumulate with each subsequent generation and can, over time, cause substantial changes in the organisms.

== rephrase ==
The concept that Gould had in 2002 with the word evolution is change in the genes of an organisms.

But Darwin didn't know about genes, who is Gould interpreting, the wikipedia nr.1 reference doesn't tell us. Who is this person that decided that "genes" must be associated with the word evolution ? Because theories are always formally defined.
The concept Darwin had with "evolution" was the unrolling of pre-fabricated beings by God , this is how a reader read OoS in 1859. Is this the same concept Gould had in 2002 and what is the relation to Genes, how did Darwin solve a problem he couldn't define.

I am the old mentari but lost my user name and password.

« Last Edit: April 01, 2009, 10:54:59 AM by mentari » Logged
Mefiante
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« Reply #10 on: April 01, 2009, 12:20:33 PM »

But Darwin didn't know about genes,…
And what of it?  Isaac Newton didn’t know about spacetime manifolds or complex numbers or photons or quantum electrodynamics either.  That hardly invalidates his observations on statics, dynamics, optics or gravity.  And nor did Darwin’s ignorance of genetics invalidate his observations re descent with modification.



… who is Gould interpreting, the wikipedia nr.1 reference doesn't tell us.
Why, he’s giving you a synopsis of things put forward by the people who put together the “modern evolutionary synthesis.”



Who is this person that decided that "genes" must be associated with the word evolution ? Because theories are always formally defined.
That would be Julian Huxley, R. A. Fisher, Theodosius Dobzhansky, J.B.S. Haldane, Sewall Wright, E.B. Ford, Ernst Mayr, Bernhard Rensch, Sergei Chetverikov, George Gaylord Simpson, and G. Ledyard Stebbins among others, i.e. the people who put together the “modern evolutionary synthesis.”



The concept Darwin had with "evolution" was the unrolling of pre-fabricated beings by God , this is how a reader read OoS in 1859.
Do you have any evidence in support of this rather remarkable contention?  Any at all?  Because your idea that Darwin’s concept had any “god” in it is, as far as I can tell, pure fabrication.  Not only that.  It also seems that none of your previous discussions here have disabused you of the ridiculous notion concerning “the unrolling of pre-fabricated beings” by your god (or anyone else, for that matter).  But even if Darwin (or any 19th century reader of his work) had inserted a god into evolution, we have learned a few things since then, including about the superfluity of a god in evolution.  Perhaps you’d care to join the rest of us here in the 21st century right after you first find out how science advances and how knowledge accumulates.



Is this the same concept Gould had in 2002…
Ignoring the fallacious take on what Darwin (or a 19th century person) had in mind with evolution, the answer is still a resounding, “No!”



… and what is the relation to Genes, how did Darwin solve a problem he couldn't define.
For the first part, read the link I provided earlier.  Then you will realise that Darwin left unsolved the problem of heredity and the mechanisms by which it proceeds.

'Luthon64
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Sentinel
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« Reply #11 on: April 01, 2009, 12:30:55 PM »

I'm in no way as knowlegable on this topic as some of the other members of the forum, but I would like to add something that may shine some light on your post, mentari.

The concept that Gould had in 2002 with the word evolution is change in the genes of an organisms.
[...]
But Darwin didn't know about genes, who is Gould interpreting... how did Darwin solve a problem he couldn't define.


What you are referring to is the scientific method, also discused here.

The wonderful thing about this, as I see it, is that it allows advancement. Theories are also constantly tested. In other words, if research provides additional information, this will be incorporated in the theory, thereby expanding what we understand about the theory and perhaps even to fine-tune the definition.

It is almost unfathomable to think that modern research into genetics can once again prove a 150 year old theory like Evolution. The scientific method has proven itself once again.

So what if the definition of the theory "evolved" as well? It still does not change the original concept, as outlined by Darwin?

In any event, I would not define Evolution as per your quote from Wikipedia. That can perhaps be classified as a description of the theory. I would, in layman's terms, define Evolution as the History of life. Scientists act as investigators, to determine this history.

In the past, they had fossil records to go by, but as science progressed, they found genetics as additional resource for their investigation. Darwin would have given anything to have had this to his disposal.

Sentinel

PS. Luthon posted something while I was typing, but I'll post this anyway
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« Reply #12 on: April 01, 2009, 12:50:32 PM »

The only comment I can make in addition to Luthon's post (that makes mine look as if it was done by a 3yr-old Smiley ) is on the following:


The concept Darwin had with "evolution" was the unrolling of pre-fabricated beings by God , this is how a reader read OoS in 1859.
Do you have any evidence in support of this rather remarkable contention?  Any at all?  Because your idea that Darwin’s concept had any “god” in it is, as far as I can tell, pure fabrication.  Not only that.  It also seems that none of your previous discussions here have disabused you of the ridiculous notion concerning “the unrolling of pre-fabricated beings” by your god (or anyone else, for that matter).  But even if Darwin (or any 19th century reader of his work) had inserted a god into evolution, we have learned a few things since then, including about the superfluity of a god in evolution.  Perhaps you’d care to join the rest of us here in the 21st century right after you first find out how science advances and how knowledge accumulates.

'Luthon64


I agree with everything that was said.

The only example that I know of, where Darwin, being a Christian at the time of his initial voyage, considered God in any of his research, can be found in the book, Saving Darwin - How to be a Christian and believe in Evolution.

I mentioned the following, in a recent post:

If you are really serious about the subject, please do yourself a favour and start by reading the following book: Saving Darwin - How to be a Christian and Believe in Evolution.

Darwin, a Christian, faced the same theological crisis we do: How can an all powerful and omniscient God allow such cruelties in nature? He studied the ichneumon wasp that lays eggs inside a caterpillar, feeding on its insides whilst keeping it alive until they themselves are ready to pupate. He could not believe that God would allow this.

This inspired him and later lead to his theory of evolution, through which he could blame natural selection for the cruelty found in nature, and not his benevolent God.


This does not mean that God forms part of Darwin's Theory. It merely suggests that, being a Christian, he would have had some thoughts on the subject.
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« Reply #13 on: April 01, 2009, 15:28:46 PM »

I am the old mentari but lost my user name and password.
To avoid confusion, please use the links provided to get new login details. If you have any problems with that PM or email me and I'll sort it out.
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Rigil Kent
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« Reply #14 on: April 01, 2009, 22:16:10 PM »

Quote
Strictly speaking, evolution is the study of gene and allele frequencies.  This means that evolution concerns itself with how certain genes (or alleles) become abundant or scarce, and the factors that play a role.

Luthon, I don't particularly like this definition because it confuses the process of evolution with the study of evolution (i.e. Biology).

Quote
Does evolution happen by chance?

What chance is will vary depending on your point of view.

If you are an objective observer of evolution, mutation will be random (non-directional, accidental) and natural selection will be a directional influence.

If you are a theistic observer of evolution, then I suspect neither mutation nor selection will happen by chance.

If you are an evolving species, both mutation and selection will be random.

If you are a collection of cellular organelles and molecules, mutation will be predetermined and unavoidable, and selection random.

Actually, I don't think the idea of CHANCE makes much sense at all.

Mintaka
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