Design implies that the optimum, can be achieved, no matter what state the species is in

[Speedwell]

"Evolution is a fact. Beyond reasonable doubt, beyond serious doubt, beyond sane, informed, intelligent doubt, beyond doubt evolution is a fact"

we may agree on something then, Dawkins is not a reputable scientist!

I don't know the context of that quote and what he was ranting against, but he is right to the extent that evolution itself is without doubt, which I think even you agree with: life on this planet has developed and diversified since it began. It's the "how" that we are talking about.

The modern synthesis of Darwinian evolution is still natural selection acting on random variation-genetic drift etc are all various selection processes rather than creative ones

So I was right; you don't understand it.

 

[Guy Threepwood]

I don't know the context of that quote and what he was ranting against, but he is right to the extent that evolution itself is without doubt, which I think even you agree with: life on this planet has developed and diversified since it began. It's the "how" that we are talking about.

He makes it clear in the larger context that he is talking about Darwinian evolution, but I'd need to find the whole paragraph.

Yes, if we define evolution as simply change in the appearance of life over time, then of course we agree-
as does Genesis which describes life originating in the ocean, with new forms appearing later, culminating with humans

I'm not a creationist - just to illustrate how wide that definition is

 

[Speedwell]

So why do you think genetic drift is a selection mechanism? Genetic drift is well established as one of the causes of random variation--along with mutation, recombination and other causes which you may not be aware of--how does it act as natural selection?

 

[Guy Threepwood]

So why do you think genetic drift is a selection mechanism? Genetic drift is well established as one of the causes of random variation--along with mutation, recombination and other causes which you may not be aware of--how does it act as natural selection?

because like all other forms of selection, you are merely selecting from pre-existing options- you cannot select something that did not already exist

Even if you want to classify that as a form of variation- it still falls within the Darwinian model (natural selection acting on random variation)

 

[Shemjaza]

because like all other forms of selection, you are merely selecting from pre-existing options- you cannot select something that did not already exist

Even if you want to classify that as a form of variation- it still falls within the Darwinian model (natural selection acting on random variation)

But genetic drift isn't a selection mechanism... it's a description of new variation from neutral mutations building up in the population.

 

[Speedwell]

because like all other forms of selection, you are merely selecting from pre-existing options- you cannot select something that did not already exist

Even if you want to classify that as a form of variation- it still falls within the Darwinian model (natural selection acting on random variation)

It's a form of genetic modification: it contributes to variation, but is not variation itself. Natural selection acts only on the variant phenotypes. .

 

[Guy Threepwood]

But genetic drift isn't a selection mechanism... it's a description of new variation from neutral mutations building up in the population.

not in the sense of 'selecting for better adaptation'

but genetic drift represents genes that are selected from pre-existing genes in the parents-

i.e. selection v origination

 

[Speedwell]

not in the sense of 'selecting for better adaptation'

but genetic drift represents genes that are selected from pre-existing genes in the parents-

i.e. selection v origination

Genes present in the parents as modified by mutation, genetic drift, recombination, etc. express themselves in the phenotype as variation.

 

[pitabread]

That's the alternative to the Darwinian mechanism of unguided 'random variation' , and is already gaining ground in secular circles: That certain specific genetic information necessary to create new biological forms was pre-existing, only needed activated not generated- Darwinism that ain't.

[citation needed]

 

[Guy Threepwood]

Genes present in the parents as modified by mutation, genetic drift, recombination, etc. express themselves in the phenotype as variation.

sure,

i can stick my hand in a jar of Jelly Bellies and select some at random or my favorite flavors, I'm not doing anything whatsoever to account for the creation of the Jelly beans

we always come back to the same question- arrival of the fittest -
Mere survival is not much debated- that's the easy part- and genetic drift is just survival of pre-existing genes.

again whether you want to describe this as selection (of existing genes) or variation (of existing genes)
it comes under the Darwinian umbrella of selection acting on random variation

 

[Speedwell]

sure,

i can stick my hand in a jar of Jelly Bellies and select some at random or my favorite flavors, I'm not doing anything whatsoever to account for the creation of the Jelly beans

we always come back to the same question- arrival of the fittest -
Mere survival is not much debated- that's the easy part- and genetic drift is just survival of pre-existing genes.

again whether you want to describe this as selection (of existing genes) or variation (of existing genes)
it comes under the Darwinian umbrella of selection acting on random variation

And the "existing genes" change, generation to generation, as selection proceeds, generation by generation.

 

[Shemjaza]

not in the sense of 'selecting for better adaptation'

but genetic drift represents genes that are selected from pre-existing genes in the parents-

i.e. selection v origination

But drift requires new variation, it doesn't explain it. Mutations are the explanation of the variation.

 

[Guy Threepwood]

But drift requires new variation, it doesn't explain it. Mutations are the explanation of the variation.

Well that's what I was saying, drift is not the origination of the variation- the variation is all ultimately down to mutation (random according to Darwinism)

so in this sense drift is merely 'selecting' pre-existing mutations- though I do see the distinction between this and 'natural selection' of better adapted traits

 

[Shemjaza]

Well that's what I was saying, drift is not the origination of the variation- the variation is all ultimately down to mutation (random according to Darwinism)

so in this sense drift is merely 'selecting' pre-existing mutations- though I do see the distinction between this and 'natural selection' of better adapted traits

Okay, I think everyone can agree with that.

What point about mutation or evolution is this relevant to?

 

[Guy Threepwood]

Okay, I think everyone can agree with that.

debate Speedwell then!

What point about mutation or evolution is this relevant to?

The point about Darwinism still relying on random variation ( mutations in the modern synthesis) to introduce novel information- started on post #38 I think, though it might have stemmed from an earlier debate over Paella recipes- you know how it goes here

 

[Speedwell]

debate Speedwell then!



The point about Darwinism still relying on random variation ( mutations in the modern synthesis) to introduce novel information- started on post #38 I think, though it might have stemmed from an earlier debate over Paella recipes- you know how it goes here

No, mutations are not random variation. Each new generation of a population produces a group of individuals exhibiting a range of variation. If you plot that variation it forms a bell curve, what mathematicians call a random distribution. That's what Darwin observed and why he called his theory "the theory of evolution by random variation and natural selection." Genetic mutations are one of the causes which contribute to the formation of that random distribution.

 

[Ophiolite]

No, mutations are not random variation. Each new generation of a population produces a group of individuals exhibiting a range of variation. If you plot that variation it forms a bell curve, what mathematicians call a random distribution. That's what Darwin observed and why he called his theory "the theory of evolution by random variation and natural selection." Genetic mutations are one of the causes which contribute to the formation of that random distribution.

It seems that this point has been made by various people, multiple times, in different ways, yet Guy seems unable or unwilling to take it on board.

 

[Guy Threepwood]

It seems that this point has been made by various people, multiple times, in different ways, yet Guy seems unable or unwilling to take it on board.

we agree, you just have to consider the original source of the variation in the genes being distributed. i.e. mutations, which are utterly random, according to ToE. no way around that

 

[Speedwell]

we agree, you just have to consider the original source of the variation in the genes being distributed. i.e. mutations, which are utterly random, according to ToE. no way around that

Just wanted to make sure we were all on the same page when it comes to what "random" means in the name of the theory. But you are right: genetic mutations are random with respect to fitness, which is why the process works the way it does. The short answer is that evolution requires diversity in the gene pool, i.e. a large amount of information, which produces a distribution of variation with a reasonably large standard deviation. Natural selection reduces the information content of the gene pool (and the standard deviation of the distribution of variation) which must be replenished of evolution is to continue. The most effective way of doing this is with a random string, which contains the most information. A good example of this is selective breeding. Intensive selection reduces the information content of the gene pool faster than it can be replenished naturally to the point where the standard deviation of the variation becomes so small that further change is impossible.

 

[tas8831]

we agree, you just have to consider the original source of the variation in the genes being distributed. i.e. mutations, which are utterly random, according to ToE. no way around that

ToE says mutations are "utterly random"? Interesting.
"Utterly random" in what regard?