What exactly is "natural selection"?

[Loudmouth]

thanks for your well thought out post, but you are missing a couple of things in regards to koonin.
first of all koonin is attempting an integration of all life, not just select groups such as plants and animals.
this makes reasonable sense.

Reasonable sense for whom?

If I am studying human evolution, why would I care about HGT in bacteria? If I am curious about neutral drift in introns, why would I study bacterial genomes that don't have introns? If I am studying adaptive evolution in primates, why would I look HGT in bacteria?

It would seem that you would focus on the mechanisms that affect the lineage you are studying. Finding HGT in bacterial evolution does not do away with the predominantly vertical genetic transmission in eukaryotes. This is also what Koonin talks about.

 

[whois]

The misunderstanding exists on your end. Koonin fully accepts that adaptive evolution is driven by natural selection.

yes, he does, but he is saying natural selection is not the dominate force of evolutionary change.
the authors that was mentioned in post 5 has proved this empirically.
furthermore koonin is saying "non-adaptive processes are much more prominent than previously suspected".
also, "There is no consistent tendency of evolution towards increased genomic complexity, and when complexity increases, this appears to be a non-adaptive consequence of evolution under weak purifying selection rather than an adaptation.".
furthermore "Of course, the neutral theory should not be taken to mean that selection is unimportant for evolution. What the theory actually maintains is that the dominant mode of selection is not the Darwinian positive selection of adaptive mutations, but stabilizing, or purifying selection that eliminates deleterious mutations while allowing fixation of neutral mutations by drift.".

 

[whois]

Reasonable sense for whom?

If I am studying human evolution, why would I care about HGT in bacteria?

oh i don't know, maybe because evolution is all about genetics, instead of select groups.

 

[SkyWriting]

There are 40 million mutations that separate humans and chimps. Are you saying that all of those mutations are harmful?

There are many such "mutations" that separate me from you.
I could say I benefitted and you lost (kidding)
Or I could say you benefited.
Or I could say there is no connection.
Or I could say that the differences you see are either designed variation, like the difference
between you and me, and the rest are harmful, like disease and such.

 

[Loudmouth]

yes, he does, but he is saying natural selection is not the dominate force of evolutionary change.

The Modern Synthesis says the same thing.

Furthermore koonin is saying "non-adaptive processes are much more prominent than previously suspected".

The Modern Synthesis is agnostic when it comes to the amount of junk DNA in any genome.

also, "There is no consistent tendency of evolution towards increased genomic complexity, and when complexity increases, this appears to be a non-adaptive consequence of evolution under weak purifying selection rather than an adaptation.".

And? Why is this a problem?

Are you saying that because some portions of the genome are not constrained by natural selection that none of the genome is constrained by natural selection?

furthermore "Of course, the neutral theory should not be taken to mean that selection is unimportant for evolution. What the theory actually maintains is that the dominant mode of selection is not the Darwinian positive selection of adaptive mutations, but stabilizing, or purifying selection that eliminates deleterious mutations while allowing fixation of neutral mutations by drift.".

Darwinian evolution also includes negative selection.

 

[Loudmouth]

oh i don't know, maybe because evolution is all about genetics, instead of select groups.

Primate evolution is not about bacterial genetics, so why include it in a study of primate evolution?

 

[Loudmouth]

There are many such "mutations" that separate me from you.
I could say I benefitted and you lost (kidding)
Or I could say you benefited.
Or I could say there is no connection.
Or I could say that the differences you see are either designed variation, like the difference
between you and me, and the rest are harmful, like disease and such.

Or, you could look at the evidence and try to arrive at a conclusion that is supported by facts. Care to try that?

 

[Dr GS Hurd]

It is ideas like "co-evolution" to explain complex interdependence that send me to the refrigerator for another beer.

Looking at an evolutionary trajectory across millions of years, and many different species which was an interaction of phenotypic variation (non-genetic adaptation), epigenetic (non-mutational genetic change), and shifts in the selection landscape due to geological change sends me to the store for another 12 pack.

 

[SkyWriting]

Or, you could look at the evidence and try to arrive at a conclusion that is supported by facts. Care to try that?

Let's see how far you can see into the past.
What was the temperature at your front door 45 minutes ago?
F or C is fine.

 

[Loudmouth]

Let's see how far you can see into the past.
What was the temperature at your front door 45 minutes ago?
F or C is fine.

As a juror, would you refuse to accept forensic evidence such as DNA evidence?

 

[sfs]

yes, he does, but he is saying natural selection is not the dominate force of evolutionary change.
the authors that was mentioned in post 5 has proved this empirically.
furthermore koonin is saying "non-adaptive processes are much more prominent than previously suspected".
also, "There is no consistent tendency of evolution towards increased genomic complexity, and when complexity increases, this appears to be a non-adaptive consequence of evolution under weak purifying selection rather than an adaptation.".
furthermore "Of course, the neutral theory should not be taken to mean that selection is unimportant for evolution. What the theory actually maintains is that the dominant mode of selection is not the Darwinian positive selection of adaptive mutations, but stabilizing, or purifying selection that eliminates deleterious mutations while allowing fixation of neutral mutations by drift.".

All of which is completely standard evolutionary biology at this point. What is not standard -- or accurate -- was your statement in a previous post. I wrote, "Adaptive evolution is almost always driven by selection," and you responded,

not according to koonin.
he seems to think adaptation is some sort of by product of evolution, that is if i understood him correctly.
apparently genomes do not evolve adaptively.

That was simply wrong. Wrong about what Koonin says, and wrong about evolution.

 

[whois]

What is not standard -- or accurate -- was your statement in a previous post. I wrote, "Adaptive evolution is almost always driven by selection," and you responded,

not according to koonin.
he seems to think adaptation is some sort of by product of evolution, that is if i understood him correctly.
apparently genomes do not evolve adaptively.

That was simply wrong. Wrong about what Koonin says, and wrong about evolution.

okay, koonin states "There is no consistent tendency of evolution towards increased genomic complexity, and when complexity increases, this appears to be a non-adaptive consequence of evolution under weak purifying selection rather than an adaptation.".

"non-adaptive consequence" implies some sort of by product, and the "non adaptive" part is the result of the complexity increase.

also, it's apparent there is a need for the definition of "genomic complexity".
or more accurately, what koonin meant by genomic complexity.

edit:
ok, i found the following dialog on genetic complexity.
whether this is koonins interpretation remains the question:
So, what does determine organismic complexity? Levine and Tjian, 2003 argue that organismic complexity correlates with an increase in the ratio and number of transcription factors per gene.
www.nature.com/hdy/journal/v93/n2/full/6800494a.html

 

[sfs]

okay, koonin states "There is no consistent tendency of evolution towards increased genomic complexity, and when complexity increases, this appears to be a non-adaptive consequence of evolution under weak purifying selection rather than an adaptation.".

"non-adaptive consequence" implies some sort of by product, and the "non adaptive" part is the result of the complexity increase.

Right. That's saying very specifically that genome complexity isn't mostly the result of natural selection.

also, it's apparent there is a need for the definition of "genomic complexity".
or more accurately, what koonin meant by genomic complexity.

edit:
ok, i found the following dialog on genetic complexity.
whether this is koonins interpretation remains the question:
So, what does determine organismic complexity? Levine and Tjian, 2003 argue that organismic complexity correlates with an increase in the ratio and number of transcription factors per gene.
www.nature.com/hdy/journal/v93/n2/full/6800494a.html

That's describing Lynch's 2003 paper on genome complexity, which is probably the basis of Koonin's comment. (I've heard Lynch talk on the subject -- he was good.) Genome complexity describes how much stuff there is in the genome. Natural selection can contribute to genome complexity (by providing pressure for a new gene, for example, or for more complex genetic regulatory mechanisms), but lots of the the complexity comes about by nonadaptive or even maladaptive processes, including transposable elements.

So that's the case for a single trait: genome complexity. It says nothing about all of the other characteristics of an organism, including all the traits that are adaptive. The latter are the result of natural selection.

 

[whois]

Right. That's saying very specifically that genome complexity isn't mostly the result of natural selection.

IOW, what i posted about what koonin said IS NOT a misrepresentation of his work, correct?

That's describing Lynch's 2003 paper on genome complexity, which is probably the basis of Koonin's comment. (I've heard Lynch talk on the subject -- he was good.)

i found the paper fairly understandable, unlike some that are totally incomprehensible.

Genome complexity describes how much stuff there is in the genome.

you are talking about more than just the number of base pairs, correct?
it seems to me that other things must be taken into account too, such as "information increase", meaning the the ability to reverse code and the number of start/stop bits.

So that's the case for a single trait: genome complexity. It says nothing about all of the other characteristics of an organism, including all the traits that are adaptive. The latter are the result of natural selection.

koonin specifically mentions "genome complexity".
the others have been dealt with by gould with his paper on spandrels.

 

[sfs]

IOW, what i posted about what koonin said IS NOT a misrepresentation of his work, correct?

That statement about Koonin was correct. Your statement that I quoted above was not correct. That's why I said it wasn't accurate.

you are talking about more than just the number of base pairs, correct?

Sure. Transposable elements add regulatory elements and entire genes to genomes.

it seems to me that other things must be taken into account too, such as "information increase", meaning the the ability to reverse code and the number of start/stop bits.

I don't know what the sentence means, or what it has to do with the issue. No one is disputing that nonadaptive processes have increased genome complexity, so it's not obvious to me why we're even talking about it.

koonin specifically mentions "genome complexity".

Which is not an adaptive trait, and thus has nothing to do with the centrality of natural selection to adaptive evolution.

the others have been dealt with by gould with his paper on spandrels.

If you think Gould dismissed natural selection as being important to adaptive evolution, you have completely misunderstood him.

 

[whois]

That statement about Koonin was correct. Your statement that I quoted above was not correct. That's why I said it wasn't accurate.

how can something be right, and wrong, at the same time?
welcome to the world of evolution that's how.
i gave koonins statement, and how i interpreted that statement
i presented a paper in post 52 which attempts to give a definition for genome complexity.
you agreed with all of that.
the authors seems to use genome and organismic interchangeably.
it doesn't take much on my part to see that organismic complexity is not driven by natural selection.
you say this is both right and wrong.
actually you said it was right, until i wanted you to verify that i wasn't misrepresenting koonin.
then it became wrong.

If you think Gould dismissed natural selection as being important to adaptive evolution, you have completely misunderstood him.

he gives a few examples in the mentioned paper that questions the idea.
i believe certain aspects of the evolution of the pandas thumb was one of them.
this was the motivation for his punctuated equilibrium hypothesis.

 

[Jan Volkes]

Let's see how far you can see into the past.
What was the temperature at your front door 45 minutes ago?
F or C is fine.

How do creationists get through the day?

 

[OldWiseGuy]

How do creationists get through the day?

I just think of the first Star Trek movie. Voyager represents the first life form. What it collected is the theory of evolution.

(I don't care whatcha say, that there now that's funny.)

 

[Jan Volkes]

How do creationists get through the day?

I just think of the first Star Trek movie. Voyager represents the first life form. What it collected is the theory of evolution.

(I don't care whatcha say, that there now that's funny.)

I was thinking more along the lines of adults thinking and believing like children.

 

[TheBear]

Here's a perfect example of natural selection - http://www.truthinscience.org.uk/ti...lution-mainmenu-65/127-the-peppered-moth.html