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What is the science of evolution?

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Nirvanam
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Re: What is the science of evolution?

#21 Post by Nirvanam » May 6th, 2010, 8:04 am

Latest post of the previous page:

grammar king wrote:Ok... I'll explain again. Mutations are passed on from parents to offspring along with other genes. A beneficial mutation is defined as one which helps the organism pass on its genes. By definition (and we're getting into tautology territory again), an organism which has this beneficial mutation is more likely to have offspring than an organism which doesn't have it. So the beneficial mutation is more likely to be passed on than the 'normal' gene, and it gradually spreads through the population purely because those with the beneficial mutation will be successful and the others will be less successful. There is no 'rule'.
I am not questioning that...my question is this: on what basis does Natural Selection process select one mutation over the other? For it to select one mutation over the other, there must be some information exchange / communication happening? Do you contend with that? If yes, then what kind of information is being exchanged?

Also, if I consider this part of your response..."an organism which has this beneficial mutation is more likely to have offspring than an organism which doesn't have it" and represent it in the following way:

chipmunk-a: no mutations
chipmunk-b: one particular negative mutation
chipmunk-c: one particular beneficial mutation
and you are saying that chipmunk-c automatically has more chance of reproducing. Why and How? Chipmunk-a is equally capable of reproducing whether it had a mutation or not, similarly chipmunk-b is also equally capable of reproduction UNLESS the mutation deals with something related to the process of reproduction itself. Whether the mutation gets passed on to the next generation is where chipmunk-b has less chance than chipmunk-c.

Would you consider chipmunk-b, if its mutation has nothing to do with reproduction abilities, somehow unable to reproduce? Or is it more accurate to say that the particular mutation of chipmunk-b may not pass on to its next generation?

Now, depending on what you think is happening, see how the probabilities then differ.

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grammar king
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Re: What is the science of evolution?

#22 Post by grammar king » May 6th, 2010, 11:55 am

Nirvanam wrote:]I am not questioning that...my question is this: on what basis does Natural Selection process select one mutation over the other? For it to select one mutation over the other, there must be some information exchange / communication happening? Do you contend with that? If yes, then what kind of information is being exchanged?

Also, if I consider this part of your response..."an organism which has this beneficial mutation is more likely to have offspring than an organism which doesn't have it" and represent it in the following way:

chipmunk-a: no mutations
chipmunk-b: one particular negative mutation
chipmunk-c: one particular beneficial mutation
and you are saying that chipmunk-c automatically has more chance of reproducing. Why and How? Chipmunk-a is equally capable of reproducing whether it had a mutation or not, similarly chipmunk-b is also equally capable of reproduction UNLESS the mutation deals with something related to the process of reproduction itself. Whether the mutation gets passed on to the next generation is where chipmunk-b has less chance than chipmunk-c.

Would you consider chipmunk-b, if its mutation has nothing to do with reproduction abilities, somehow unable to reproduce? Or is it more accurate to say that the particular mutation of chipmunk-b may not pass on to its next generation?

Now, depending on what you think is happening, see how the probabilities then differ.
As I said several times, a beneficial mutation is defined as one which helps the organism reproduce. So yes, chipmunk c will be more likely to reproduce than chipmunk b and a. Now the mutation doesn't have to be directly related to the act of reproduction, if it helps the organism survive then it'll also work, because organisms that survive longer are more likely to have more offspring.

philbo
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Re: What is the science of evolution?

#23 Post by philbo » May 6th, 2010, 12:09 pm

Nirvanam wrote:I am not questioning that...my question is this: on what basis does Natural Selection process select one mutation over the other? For it to select one mutation over the other, there must be some information exchange / communication happening? Do you contend with that? If yes, then what kind of information is being exchanged?
I don't understand why you seem to find this so hard to understand... there is no entity "Natural Selection" making an active choice of one mutation over another. It's just that some mutations make reproduction or staying alive slightly easier so will become more prevalent down the generations.

Nobody "makes the choice", it's just that some mutations aid survival or reproduction. It really is that simple.

Nirvanam
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Re: What is the science of evolution?

#24 Post by Nirvanam » May 6th, 2010, 5:59 pm

grammar king wrote:
Nirvanam wrote:]I am not questioning that...my question is this: on what basis does Natural Selection process select one mutation over the other? For it to select one mutation over the other, there must be some information exchange / communication happening? Do you contend with that? If yes, then what kind of information is being exchanged?

Also, if I consider this part of your response..."an organism which has this beneficial mutation is more likely to have offspring than an organism which doesn't have it" and represent it in the following way:

chipmunk-a: no mutations
chipmunk-b: one particular negative mutation
chipmunk-c: one particular beneficial mutation
and you are saying that chipmunk-c automatically has more chance of reproducing. Why and How? Chipmunk-a is equally capable of reproducing whether it had a mutation or not, similarly chipmunk-b is also equally capable of reproduction UNLESS the mutation deals with something related to the process of reproduction itself. Whether the mutation gets passed on to the next generation is where chipmunk-b has less chance than chipmunk-c.

Would you consider chipmunk-b, if its mutation has nothing to do with reproduction abilities, somehow unable to reproduce? Or is it more accurate to say that the particular mutation of chipmunk-b may not pass on to its next generation?

Now, depending on what you think is happening, see how the probabilities then differ.
As I said several times, a beneficial mutation is defined as one which helps the organism reproduce. So yes, chipmunk c will be more likely to reproduce than chipmunk b and a. Now the mutation doesn't have to be directly related to the act of reproduction, if it helps the organism survive then it'll also work, because organisms that survive longer are more likely to have more offspring.
Would you be able to direct me to some source that can confirm this exact understanding of the chance involved in mutations passing through, please?

Also, if I am understanding you right, you are saying that the characterization of a mutation as 'beneficial' is post-facto i.e. we call it beneficial only after it has made it through...right? If that is the case then how do we even know there were any other mutations at all, other than the ones that made it through?

Nirvanam
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Re: What is the science of evolution?

#25 Post by Nirvanam » May 6th, 2010, 6:21 pm

philbo wrote:
Nirvanam wrote:I am not questioning that...my question is this: on what basis does Natural Selection process select one mutation over the other? For it to select one mutation over the other, there must be some information exchange / communication happening? Do you contend with that? If yes, then what kind of information is being exchanged?
I don't understand why you seem to find this so hard to understand... there is no entity "Natural Selection" making an active choice of one mutation over another. It's just that some mutations make reproduction or staying alive slightly easier so will become more prevalent down the generations.

Nobody "makes the choice", it's just that some mutations aid survival or reproduction. It really is that simple.
I am not saying that Natural Selection is an entity. I am only asking you to define it when you say that evolution happens through random mutation which is as a result of 'natural selection'. It is this viewpoint that is bringing life to the term 'natural selection'. And the current definition of natural selection as a process of chance is making evolution seem to be an impossibly lucky coincidence.

Ok, just forget about evolution and consider a simple example...2 monkeys jump from one branch to the other: one of the monkeys makes a proper jump while the other monkey falls down. Both of them are doing the same thing i.e. jump, but one of them is successful whereas the other fails. During the jumping process something decided why one monkey was able to succeed and the other failed...could be weight of the monkey, branch strength, whatever.

Similarly, an organism with two distinct mutations mates. One mutation is successfully passed on whereas the other one fails. Something decides their fate? You must believe that something has decided which passes on and which doesn't if you believe in a causal universe. Otherwise it would mean that there was no assignable cause to why the mutation passed or why it failed which contradicts the understanding of the universe being causal in nature, isn't it?

What we are doing now, is just saying that whichever passed is the beneficial one and whichever did not is the useless one. That is OK as a post-facto definition but it does not help us understand the evolutionary process. Or if you think that it is explaining to you the evolutionary process, then please detail it out...I haven't come across any explanation about the evolutionary process itself except the mention of the term 'natural selection' and the phrase "it is beneficial because it passed thru" stated in different ways. That is not an explanation, it is only an observation.

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Re: What is the science of evolution?

#26 Post by philbo » May 6th, 2010, 9:53 pm

Nirvanam wrote:I am only asking you to define it when you say that evolution happens through random mutation which is as a result of 'natural selection'.
NO!

Mutation doesn't happen "as a result of natural selection" (if that were the case, it wouldn't be random, would it?)


Mutations happen. Got it so far?

Nothing has to make the mutations happen - it's part of an imperfect copying process*

Some mutations can't be passed on.. so they have no evolutionary effect.
Some mutations don't have any noticeable effect.. they'll get passed on, but, well, who cares if they don't have any noticeable effect?
Some mutations are actively deleterious - they'll die out pretty quick, if that's the case

But...
Some mutations actually help.. in the case of your monkey jumping, for example: if the reason one monkey could jump better than another were genetic (e.g. a slightly longer tail, or a better gripping hand, or a tendency towards binocular vision), and that could be passed on.. then over the generations, mutations which aided jumping accuracy would accumulate and make for much better-jumping monkeys. (At the risk of confusing you more than you seem to be already, this doesn't actually require mutation if the gene pool already contains enough variability.)

The selection filter isn't usually "this animal with mutation will survive"/"this one without will die".. just being slightly better & more successful (passing on your genes, on average, to more offspring) means as generations pass, the "useful" mutation will become more and more prevalent.




* If you're getting more advanced in your thinking, you might think "surely a perfect copying process would be better?".. yet an imperfect one, which allows for change, will easily out-evolve a perfect copying process. Work it out..

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Re: What is the science of evolution?

#27 Post by Nirvanam » May 7th, 2010, 10:27 am

philbo wrote:
Nirvanam wrote:I am only asking you to define it when you say that evolution happens through random mutation which is as a result of 'natural selection'.
NO!

Mutation doesn't happen "as a result of natural selection" (if that were the case, it wouldn't be random, would it?)


Mutations happen. Got it so far?

Nothing has to make the mutations happen - it's part of an imperfect copying process*
My bad..what I meant to say was that evolution is made possible by natural selection.
philbo wrote:Some mutations can't be passed on.. so they have no evolutionary effect.
Do we know why? This is a very important question to answer. Depending on how we answer this question we will be able to claim whether we understand how evolution works or not
philbo wrote:Some mutations don't have any noticeable effect.. they'll get passed on, but, well, who cares if they don't have any noticeable effect?
Some mutations are actively deleterious - they'll die out pretty quick, if that's the case
Again same question applies here also, but anyway let's leave these ones and concentrate on the fully false and fully true things.
philbo wrote:But...
Some mutations actually help..
which we observe only after the mutation happens successfully..rather we conjecture that there must have been a mutation which allowed specie monkey x to evolve into specie monkey y having a longer tail
philbo wrote: in the case of your monkey jumping, for example: if the reason one monkey could jump better than another were genetic (e.g. a slightly longer tail, or a better gripping hand, or a tendency towards binocular vision), and that could be passed on..
Here is where I am asking what does the probability value look like
philbo wrote:then over the generations,
so probability now becomes x < 1 * y < x where x is probability of the first mutated monkey reproducing (considering the probability of it finding a mate, living long enough to find a mate, etc, etc) and y is the probability of x's offspring reproducing. What does the probability value look like say after 10 generations?
philbo wrote: mutations which aided jumping accuracy would accumulate and make for much better-jumping monkeys. (At the risk of confusing you more than you seem to be already, this doesn't actually require mutation if the gene pool already contains enough variability.)

The selection filter isn't usually "this animal with mutation will survive"/"this one without will die".. just being slightly better & more successful
Let's not go there...slightly better/worse is a function of degree or intensity of something...what is that something? chance? cannot be, no?
philbo wrote: (passing on your genes, on average, to more offspring) means as generations pass, the "useful" mutation will become more and more prevalent.
OK, if I can express this in terms of probability what may happen is that as generations go on the probability value will keep dropping and dropping until it reaches a certain value from where the probability will start reversing that is it will start increasing....a beneficial mutation will go stop at that value and start to reverse whereas a non beneficial mutation will not stop at all and keep reducing further. Sounds good for an observation but still leaves the main question unanswered.

That was just imaginary construct...only to help me understand the logic.
philbo wrote:* If you're getting more advanced in your thinking, you might think "surely a perfect copying process would be better?".. yet an imperfect one, which allows for change, will easily out-evolve a perfect copying process. Work it out..
Will pass that...my head's already spinning trying to understand this simple 'chance' theory..lol!

Let me state my viewpoint on evolution currently...
a. Evolution is a foregone conclusion...it exists, it happens.
b. Our current understanding of why evolution happens is that it is a random chance event.
c. Therefore, whenever any explanation is put forward that evolution is not a chance event then the burden of proof lies on that explanation.
d. In other words, our Null Hypothesis is that "evolution is a chance event".
e. If the guy who first chose this to be the Null Hypothesis stated the Null Hypothesis as "Evolution is not a chance event" then too we wouldn't have proved the Alternate Hypothesis as true.
f. We have to contend with the arbitrary nature of choosing the Null Hypothesis and live with it.

g. Evolution is a process. A process necessarily has an input and an output.
h. In all things that we see around us, whether natural or artificial, the process is either coded/rigid (as in 2 parts of H when combine with one part of O there can only be water and no other output) or there is a communication/information exchange or a mix of the two. There is no other possibility.
i. If our Null Hypothesis = "Evolution is a chance event" then the process of Evolution is necessarily not a coded/rigid process.
j. Therefore, Evolution requires some form of information exchange.
k. When an information exchange happens, the resultant output from the processing depends upon the content of that information in other words there must exist some rule(s) which will process that information further.
l. We currently do not know what those rules are

Given the above, I cannot either be sure that evolution is purely a chance thing or not. I'd like to know where in the above points does it turn for you in favor of evolution totally being a chance event. If the points I have made above are incorrect, please help me correct them.


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Re: What is the science of evolution?

#29 Post by philbo » May 7th, 2010, 4:52 pm

Nirvanam wrote:
philbo wrote:Some mutations can't be passed on.. so they have no evolutionary effect.
Do we know why? This is a very important question to answer. Depending on how we answer this question we will be able to claim whether we understand how evolution works or not
If you were actually to think about it, you'd realize that changes which aren't passed on are completely and utterly irrelevant - pretty much by definition, they can have no evolutionary effect, so the "why" they don't get passed on really doesn't matter.

Nirvanam wrote:
philbo wrote:Some mutations don't have any noticeable effect.. they'll get passed on, but, well, who cares if they don't have any noticeable effect?
Some mutations are actively deleterious - they'll die out pretty quick, if that's the case
Again same question applies here also, but anyway let's leave these ones and concentrate on the fully false and fully true things.
"Fully false"/"fully true"???

We're not talking true or false - just that these things happen and may or may not have a good/bad/indifferent effect and may or may not get passed on. That pretty much covers all available permutations.
Nirvanam wrote:
philbo wrote:But...
Some mutations actually help..
which we observe only after the mutation happens successfully..rather we conjecture that there must have been a mutation which allowed specie monkey x to evolve into specie monkey y having a longer tail
Exactly - nobody *plans* the mutation beforehand. There is no guiding force that says "If you had a longer tail, you'd be able to jump better, so I'll give you a longer tail".

Just having a longer tail probably wouldn't necessarily involve a new species - speciation isn't an exact line to be crossed, but there comes a point when too many deviations from the norm mean that animals can no longer cross-breed. There are examples in the animal world where you have, say, groups A, B and C, where A can interbreed with B, B can interbreed with C but A can't produce offspring with C. If you see what I mean.
Nirvanam wrote:
philbo wrote: in the case of your monkey jumping, for example: if the reason one monkey could jump better than another were genetic (e.g. a slightly longer tail, or a better gripping hand, or a tendency towards binocular vision), and that could be passed on..
Here is where I am asking what does the probability value look like
Try to get your head around this: it really doesn't matter what the probability is. If a change is beneficial (i.e. results in a higher probability of survival and/or increased number of offspring) and inheritable, the actual level of probability makes no difference at all to whether a gene will propagate, but will affect the rate.

Nirvanam wrote:
philbo wrote:The selection filter isn't usually "this animal with mutation will survive"/"this one without will die".. just being slightly better & more successful
Let's not go there...slightly better/worse is a function of degree or intensity of something...what is that something? chance? cannot be, no?
You're conflating two different definitions of "chance" - there is the "chance", sort of random aspect of a mutation occurring; there is also a difference in "chance" - probability of a mutation making survival more likely. That second probability in effect *is* the natural selection filter that makes successful changes survive and others die out.
Nirvanam wrote:Let me state my viewpoint on evolution currently...
a. Evolution is a foregone conclusion...it exists, it happens.
True
Nirvanam wrote:b. Our current understanding of why evolution happens is that it is a random chance event.
It is not "a random chance event" - it is the result of many millions/billions of random chance events, with the unsuccessful ones filtered out in a process we call "natural selection"
Nirvanam wrote:If the points I have made above are incorrect, please help me correct them.
It's not that the points you make are incorrect, you're just going out of your way to make things way more confusing than they actually are.

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Re: What is the science of evolution?

#30 Post by Nirvanam » May 7th, 2010, 5:57 pm

philbo wrote:
Nirvanam wrote:b. Our current understanding of why evolution happens is that it is a random chance event.
It is not "a random chance event" - it is the result of many millions/billions of random chance events, with the unsuccessful ones filtered out in a process we call "natural selection"
Yes, I understand that...my question, to repeat, is, do you know what is "natural selection"? All you have told me about natural selection is that, one mutation by chance goes thru whereas some other mutation by chance does not go thru. This 'going thru or not' = natural selection.

Unless you construct even a simple probabilistic model to understand what kind of random chance we are dealing with, you may not understand why I feel that evolution is definitely not totally based on chance.

Also, try and view it from a larger perspective of what we mean by a causal universe...what differentiates a causal phenomenon from a non-causal phenomenon. How many naturally occurring phenomena have you heard of that are not based on cause-effect relationships?

Let me ask you this: Is evolution a causal process? I am not referring to the post-facto part of the process i.e. because a mutation survived therefore we have this new organ developing in the animal. I am referring to the part of the process that precedes it...what you call the natural selection filter. Is that causal? Also name one more natural phenomenon which is not causal but entirely based on chance as this natural selection process appears to be.

If you agree that there is some information exchange happening during the natural selection process then why is it difficult for you to allow the possibility that it is the content of the information that can hold the key to why one mutation survived whereas another died.

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Re: What is the science of evolution?

#31 Post by Nirvanam » May 7th, 2010, 6:01 pm

grammar king wrote::headbang: :headbang: :headbang:
You know, we always have the option of ignoring and moving on or just saying something on the lines of "I dont think I am getting thru to you and I am not sure if I want to try any longer". Why unnecessarily trouble ourselves with non-happy thoughts and expressions and make it known that they are troubling us? Let go, it might just make you see me and yourself in a different light :smile:

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Re: What is the science of evolution?

#32 Post by philbo » May 9th, 2010, 11:50 pm

Nirvanam wrote:
philbo wrote:
Nirvanam wrote:b. Our current understanding of why evolution happens is that it is a random chance event.
It is not "a random chance event" - it is the result of many millions/billions of random chance events, with the unsuccessful ones filtered out in a process we call "natural selection"
Yes, I understand that...my question, to repeat, is, do you know what is "natural selection"?
Yes.

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Re: What is the science of evolution?

#33 Post by Paolo » May 10th, 2010, 1:09 pm

Nirvanam wrote:
philbo wrote:It is not "a random chance event" - it is the result of many millions/billions of random chance events, with the unsuccessful ones filtered out in a process we call "natural selection"
Yes, I understand that...my question, to repeat, is, do you know what is "natural selection"? All you have told me about natural selection is that, one mutation by chance goes thru whereas some other mutation by chance does not go thru. This 'going thru or not' = natural selection.
Natural Selection is the name given to a suite of processes that work at a variety of levels. It includes anything that prevents an organism from passing on its genes and it also includes anything that makes an organism better at passing on its genes.
Nirvanam wrote:Unless you construct even a simple probabilistic model to understand what kind of random chance we are dealing with, you may not understand why I feel that evolution is definitely not totally based on chance.
We know that evolution is not based on chance alone. The only people in the world who claim that evolution is based on chance alone are proponents of Intelligent Design, who all lack a basic understanding of the biological processes that are essential to understand when considering the mechanism of evolution.
Probabilistic models are severely limited in their power when applied to evolutionary questions because there is no way to adequately account for the actions of Natural Selection. For example, what are the odds of someone winning a coin flip twenty times in a row? I think it’s about 1 in 2,74,878,000,000. However, if you took 524,288 people and put them in a competition where they all formed in pairs and tossed a coin, with the winner of each round moving into the next round and the loser being disqualified, you would end up with one person at the end of 20 rounds who had won the coin flip 20 times in a row. More importantly, the process of selection in this case (losers go out, winners carry on) makes it impossible for there to not be someone who manages to win a coin flip 20 times in row. Natural Selection is a bit like this, but with the competition working at a huge variety of levels and many more competitors taking part. This makes probabilistic models poorly suited to the task of addressing evolution.
Nirvanam wrote:Also, try and view it from a larger perspective of what we mean by a causal universe...what differentiates a causal phenomenon from a non-causal phenomenon. How many naturally occurring phenomena have you heard of that are not based on cause-effect relationships?

Let me ask you this: Is evolution a causal process? I am not referring to the post-facto part of the process i.e. because a mutation survived therefore we have this new organ developing in the animal. I am referring to the part of the process that precedes it...what you call the natural selection filter. Is that causal? Also name one more natural phenomenon which is not causal but entirely based on chance as this natural selection process appears to be.
You are not getting this at all. Natural Selection is not based on chance.
Nirvanam wrote:If you agree that there is some information exchange happening during the natural selection process then why is it difficult for you to allow the possibility that it is the content of the information that can hold the key to why one mutation survived whereas another died.
Sorry Nirvanam, but you are discussing a topic that requires a fair bit of background knowledge about the mechanisms and processes involved. At the moment your arguments sound like someone trying to say that it’s impossible for a computer to work, because they don’t understand how it works – we need to get your basic knowledge of the subject up to speed so you can build up to the bigger questions you are interested in.

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Re: What is the science of evolution?

#34 Post by jaywhat » May 10th, 2010, 1:55 pm

Perhaps some of us would benefit by a couple of suggestions for reading matter, however basic, that would fill in a few of the missing bits of knowledge for those interested in following this up.

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Paolo
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Re: What is the science of evolution?

#35 Post by Paolo » May 10th, 2010, 4:40 pm

The Origin of Species is a good place to start.

Here are the most fundamental principles of evolution, which are commonly referred to using the acronym VISTA: Variation Inheritance Selection Time Adaptation

Variation happens – we can see it in a population and we know it's caused by mutation (and occasionally by hybridisation). Some variations confer advantages or disadvantages.

Inheritance happens – we know how genes are passed from a parent organism to its offspring. We also know that variations in a parent are passed on to at least some of their offspring.

Selection happens – we know that not all individuals from a generation survive to reproduce. We also know that some variations improve or reduce the chances of an individual surviving to reproduce. Changes in the environment can change how much influence selection has, because selection is driven by an organism’s environment (everything from resource availability, predation, mate availability, temperature, climate, competition, etc.).

Time passes – we know that the Earth is ancient (4.6 billion years) and that there is plenty of time for billions upon billions of generations of life to be born and reproduce. This constant process means that tiny changes that arise as a result of selection can slowly build up, changing the genetic make-up of a population until it becomes distinct from what came before.

Adaptation – we can compare adaptations of different organisms and see how they are related, we can watch the development of adaptations in embryos and see that they follow pathways that only make sense if the organisms are related to other forms of life. We can track these similarities in fossils and they converge as you go back through time, just as though you were tracing a tree branch from its tip down towards the trunk – a pattern that can only be adequately explained (given our knowledge of genetics and living organisms) by the branching off of species from each other.

Nirvanam needs to separate out this idea that mutations and random change are the only factors in evolution. Selection is an observable phenomenon and it shapes organisms based on the environment in which they have to survive.

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jaywhat
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Re: What is the science of evolution?

#36 Post by jaywhat » May 10th, 2010, 5:11 pm

Thanks for that Paolo. I've read Darwin's 'Origin' and 'The Descent of Man' and a few other things such as -
'99% Ape' by Jonathan Silvertown
'Darwin's Island' by Steve Jones
'Catching Fire' by Richard Wrangham
'The Complete World of Human Evolution' by Chris Stringer and Peter Andrews
'The Incredible Human Journey' by Alice Roberts

.., but thanks for your useful VISTA.

I enjoy this subject so much and it's not so much to show off but to share these titles with others that I list them.

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Re: What is the science of evolution?

#37 Post by Nirvanam » May 10th, 2010, 7:23 pm

Paolo wrote:Natural Selection is the name given to a suite of processes that work at a variety of levels. It includes anything that prevents an organism from passing on its genes and it also includes anything that makes an organism better at passing on its genes.
This is more explanatory than what was attempted on the thread before...
Paolo wrote:We know that evolution is not based on chance alone. The only people in the world who claim that evolution is based on chance alone are proponents of Intelligent Design, who all lack a basic understanding of the biological processes that are essential to understand when considering the mechanism of evolution.
This is what I was arguing about...that evolution cannot be based on chance alone. And I think grammar king and philbo were basically indicating that it is based on chance alone and hence I went into the probabilities and whatever else I went into.
Paolo wrote:Probabilistic models are severely limited in their power when applied to evolutionary questions because there is no way to adequately account for the actions of Natural Selection. For example, what are the odds of someone winning a coin flip twenty times in a row? I think it’s about 1 in 2,74,878,000,000. However, if you took 524,288 people and put them in a competition where they all formed in pairs and tossed a coin, with the winner of each round moving into the next round and the loser being disqualified, you would end up with one person at the end of 20 rounds who had won the coin flip 20 times in a row. More importantly, the process of selection in this case (losers go out, winners carry on) makes it impossible for there to not be someone who manages to win a coin flip 20 times in row. Natural Selection is a bit like this, but with the competition working at a huge variety of levels and many more competitors taking part. This makes probabilistic models poorly suited to the task of addressing evolution.
Although the example does show probability in a different view, I am not sure it totally addresses the evolution concept. Anyway it doesn't matter really, coz evolution is definitely not based on chance alone is what i was arguing for and in this post you are confirming my belief.
Paolo wrote:You are not getting this at all. Natural Selection is not based on chance.
you probably misread my arguments...I am not the one arguing for chance, I am actually saying that evolution cannot be a chance event.
Paolo wrote:Sorry Nirvanam, but you are discussing a topic that requires a fair bit of background knowledge about the mechanisms and processes involved. At the moment your arguments sound like someone trying to say that it’s impossible for a computer to work, because they don’t understand how it works – we need to get your basic knowledge of the subject up to speed so you can build up to the bigger questions you are interested in.
Fair enough. But so far I have been getting it right...and its only based on logic and fairly general knowledge on various things...I don't think we would need in depth knowledge of the subject to answer the question "is evolution a totally random chance event?" Just general knowledge can help us understand that evolution is definitely not a chance event...and hence I was presenting it from different perspectives to show on what basis I was able to hold a viewpoint that evolution cannot be based on chance alone.

Now it seems more like, the intelligence design viewpoint that I was thought to have possessed is anything but and that the 100% chance viewpoint is closer to the intelligence design viewpoint. This is an example of psychological inertia: when we hear or come across terms/arguments that we heard from someone who had a certain viewpoint, our brains tend to label the new argument as also being equivalent/similar to the other viewpoint.

Paolo, the material you suggested...do they address the "why" and "how" of natural selection. Your definition of the "what" of natural selection is fairly simple to understand. Probably the "why" would be difficult to answer, I mean its like answering the question "why does life exist?". The "how" should be very interesting though...how exactly natural selection chooses one mutation over the other, how the information exchange happens, etc, etc

edit: I had earlier referred to getreal instead of grammar king...I always confuse them lol!

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Val
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Re: What is the science of evolution?

#38 Post by Val » May 10th, 2010, 8:32 pm

I too am enjoying this topic although I can only just follow it. Keep it up you lot, I am learning.

philbo
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Re: What is the science of evolution?

#39 Post by philbo » May 11th, 2010, 11:26 am

Nirvanam wrote:
Paolo wrote:We know that evolution is not based on chance alone. The only people in the world who claim that evolution is based on chance alone are proponents of Intelligent Design, who all lack a basic understanding of the biological processes that are essential to understand when considering the mechanism of evolution.
This is what I was arguing about...that evolution cannot be based on chance alone. And I think grammar king and philbo were basically indicating that it is based on chance alone and hence I went into the probabilities and whatever else I went into.
I was? That's news to me :)

At the risk of confusing you just when you seem to be getting the idea..
Paolo wrote:Natural Selection is the name given to a suite of processes that work at a variety of levels. It includes anything that prevents an organism from passing on its genes and it also includes anything that makes an organism better at passing on its genes.
...beautifully and concisely put :)

The way I look at it is that Natural Selection changes the odds: the survival & inheritance of an individual's genes is still a chance event - there are a lot of random events that can affect an individual's life, yet tweaking the odds in the race to survive/procreate changes the overall outcome, and it doesn't take much of a change in odds to have a large effect over the generations.

If a horse's handicap weights fall off at the start of a race, it doesn't guarantee it winning, but it does tip the odds more in its favour. There is still an element of chance, yet the lack of handicap weights changes the odds...

Nirvanam
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Re: What is the science of evolution?

#40 Post by Nirvanam » May 11th, 2010, 8:51 pm

OK, this is not pertaining to the topic of evolution but when I read philbo's example of the horse's chances of winning a race, a thought popped up...

What is our current understanding as per science of the nature of our universe...is it, a. causal? b. deterministic? Let me explain what I mean by those two terms so that I can be sure of what I am intending to say.

Causal = every event must have had one or more events occurring before/during it in order to make that event possible
Deterministic = the outcome of any process is always the same given that the inputs and the process itself are the same...of course allowing for natural variation. For ex - act of reproduction of humans will reproduce a human (variation here = height, weight, etc) and not a tree or something else. Another example: 2 Hydrogens and 1 Oxygen will always produce water and not CHO.

If our universe is Deterministic, then would there really be any random events? Or would "random event" just mean that we have just not studied it still to be sure it is truly random

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CurtisB
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Re: What is the science of evolution?

#41 Post by CurtisB » May 11th, 2010, 9:45 pm

Paolo wrote: Probabilistic models are severely limited in their power when applied to evolutionary questions because there is no way to adequately account for the actions of Natural Selection. For example, what are the odds of someone winning a coin flip twenty times in a row? I think it’s about 1 in 2,74,878,000,000. However, if you took 524,288 people and put them in a competition where they all formed in pairs and tossed a coin, with the winner of each round moving into the next round and the loser being disqualified, you would end up with one person at the end of 20 rounds who had won the coin flip 20 times in a row. More importantly, the process of selection in this case (losers go out, winners carry on) makes it impossible for there to not be someone who manages to win a coin flip 20 times in row. Natural Selection is a bit like this, but with the competition working at a huge variety of levels and many more competitors taking part. This makes probabilistic models poorly suited to the task of addressing evolution.
Ahhh very interesting rebuttal to the probability issue so many people seem to have...

As to what I gather is still a main focus here for Nirvanam, the process of natural selection, I'm not nearly as eloquent or talented a communicator as others who've tried so I'm afraid to add my 2 cents, but here goes anyway:

Imagine organism A1 and organism A2.. they are cousins where A1 is a 'wild type' (consider him not mutated for the sake of discussion) and A2 has a mutation that allows him to stay alive in a harsh winter.... A1 and A2 each have offspring, and by chance (maybe I shouldn't use that word, lol) A1 offspring remain 'wilf type' variants, and A2 offspring carry the A2 mutation...

Well, so far, there is a balance between these two generations, and so it would continue generation after generation, UNTIL it so happened that there was a particularly harsh winter that killed-off most or all of the 'wild type' variations of this species. Lucky for the species, however, there has been this A2 variation floating through the gene-pool, completely unseen for generations because there had previously been NO NATURAL SELECTION for that mutation. Only where there was an environmental change that delineated A1 wild types from A2 mutants was there any impact in the gene-pool caused by NATURAL SELECTION.

Et viola... One case-study of natural selection at work...

Hope that helps more than hurts this discussion!!!
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