Constructive Neutral Evolution

So how many different types of routes are there to IC structures. You have your more direct route with a mullerian two-step event where there’s positive selection at every step (if I’m understanding that event correct correctly, a more indirect route with an instance of exaption, and completely by chance as laid out by CNE. Good rough summary?

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Mullerian two step does not require selection (see my notes on it). CNE is exactly the same thing, but on a system level.

Start with a system. Add a new interactions/parts somewhere (very easy to do), at some point along the line make some of those interactions/parts necessary (very easy to do). CNE is a mullerian two step. Very easy to do.

On easy way to add a new part is duplication with divergence.

Interactions are very easy to evolve because it is the chance times the square of the number of parts. It is very likely to happen some where some how in a complex system.


Not sure I agree with that. How do you make a part “necessary” without involving selection?

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Neutral drift.

I was typing out a reply and realized what you meant. I agree. Carry on.

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6 posts were split to a new topic: X-Men Constructive Neutral Evolution

Can anyone explain how neutral change can find function in a sequence that is very different then the starting functional sequence?

We have been waiting for Behe to respond to @art on T-urf13. That is an example of finding a very new function from a starting function. It was not selected either, which means it was by essentially neutral processes.

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This was piecing existing sequences together with genetic recombination. Very different then the question I am asking.

That is how evolution works, shuffling around existing information to make new information. Shuffling things around a lot, and it is a very different sequence.

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So is the mechanism you are proposing genetic recombination as a deterministic mechanism?

There is an immense amount of randomness. There are point mutations too. Remember Behe’s response?

Sure but none of this may be the cause of the innovative transitions. Even partial random change is not a good hypothesis for the origin of a very complex functional sequence.

You may find an exception but that does not make it the rule.

Nonsequitor @colewd. We are talking about complexity arising by neutral drift, not innovation. The point is that if complexity can arise neutral, it can certainly also arise by selection, or be selected later.

By neutral changes in the sequence occurring, and among those changes are new functions found?

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So how many constructive changes are possible in the modern human genome? You need this number before you can ask how probable it is that one will occur. From my knowledge, no one knows how many beneficial mutations are possible in the modern human genome so this probability isn’t calculable.

We do know that many beneficial mutations require the presence of a previously neutral mutation. This is certainly the case for duplicated genes.


Gene duplications are a great example of largely neutral and constructive mutations.

And yes, duplications are taking place all the time. There is nothing improbable about them. It is possible, perhaps even likely, that every single birth includes at least one duplication.

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There are several papers that have genome sequences for family trios (coverage may be low). It might be worthwhile to dig through them and see if they were able to measure the rate of larger scale duplications.


What does complexity in itself explain?

It explains why we see so much apparently “irreducible” complexity in life. It explains why the so called “minimal cell” is likely not the simplest cell possible. It shows why IC is not a solid argument for design. And so on and so on.

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