Could the appearance of "complexity" be predicted with the theory of evolution?

[MonDie]

Just an ameuter speculating. My knowledge of evolution isn't that great, so my proposals might have been proposed already.

One classic example of supposed irreducible complexity was the flagellum. Since then, we've learned of a simpler structure that could have been a stepping stone to the flagellum. Still, there is probably a relationship between (1) the likeliness of a functional thing evolving and (2) the specifity of the requirements for the function. That's when I wondered what population variables would impact the likeliness of such "complex" structures appearing.

 

First of all, each population of bacteria contains TONS of viable individuals. This could definitely give those "complex" structures better chances. Thus the appearance of a "complex" structure (the flagellum) in bacteria shouldn't be surprising. With the rest of this post, I will propose other variables that will be more controversial.

 

Suppose E, N, and W are various mutations that, when appearing together in a single organism, form KNEW, a "complex" structure. K is a trait that is already widespread.

KNEW has better chances of appearing at times when E, N, and W are relatively more advantageous. One problem is that we don't know anything about E, N, or W. Despite this, there are ecological and anatomical variables that might help any new mutations, including E, N, and W. Hypothetically, such variables effect how genetically diverse a population is.

 

The first variable is reproductive age. My reasoning goes like this. If the reproductive age is later in the lifespan, mutants are less likely to survive to the reproductive age. In such a situation, new mutations will be whiped out before they can appear in many generations/recombinations. On the other hand, a population with a lower reproductive age should be more genetically diverse (testable prediction!).

 

I call the second variable transitional environment. My reasoning goes like this. When the environment is changing rapidly or a new environment is being colonized, the widespread traits are no longer advantageous, thus competition is less of a problem for mutants. Thus the population will temporarily be more diverse (testable prediction!).

Edited January 10, 2013 by Mondays Assignment: Die

[ydoaPs]

"Irreducable Complexity" was a prediction of evolution long before Behe was even born let alone before he decided that a prediction of evolution was somehow a problem for evolution.

[MonDie]

The steps can be functionally beneficial (adaptive) or not (neutral). We don't even need to invoke natural selection in the process — genetic drift or neutral evolution will do⁴.

 

http://www.talkorigins.org/faqs/comdesc/ICsilly.html

 

 

Ahh, there we go. Genetic drift can result from the bottleneck effect and the Founder effect. The Founder effect is part of what I was talking about with "transitional environment." (NOTE: "transitional environment" is not a formal biology term)

 

So, does genetic drift result in more unique combinations of genes? In a larger population, there may be just as many mutations, but it is unlikely that those mutations will recombine because they are dilluted by (and competing with) all the common traits.

 

Also, does a lower reproductive age result in greater genetic drift?

 

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If that's all Behe meant, I might need to explain what I am talking about. In example one, the stone bridge could stand on block 1&2, 1&3, or 2&3, thus the demands for the function aren't very specific. I am talking about something that has specific demands, the specifity of which makes them hard to meet.

 

Here is an example. A blunt object is something that can be useful, but the demands for the function are vague. There are tons of things that can serve as blunt objects. On the other hand, something like a flagellum has more specific demands, which means there are fewer "stepping stones" that could lead to that function. We might expect such structures to appear during times of genetic drift.

Edited January 10, 2013 by Mondays Assignment: Die

[overtone]

The more realistic computer models of systems undergoing Darwinian evolution produce arbitrary levels of complexity from much simpler inputs in silico.

 

That amounts to a prediction of what would happen in vivo, and the prediction is borne out (that is used to check the models, rather than evaluate the reality - the production of complexity via evolution in the real world is essentially an established fact).

 

Historically, we started with an overwhelming complexity in need of explanation - that obscures the fact that had we started with the principles of evolution in some setting unconnected with biology we could have predicted very complex consequences of long term operation in a suitable system.

[MonDie]

The more realistic computer models of systems undergoing Darwinian evolution produce arbitrary levels of complexity from much simpler inputs in silico.

Where can I learn about these models?

 

I might not respond since I intend to abandon this forum account once and for all.

 

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I wasn't asking whether such structures would be predicted at all, but whether the predictions could be more finely tuned.

Edited January 11, 2013 by Mondays Assignment: Die

[jp255]

 

The more realistic computer models of systems undergoing Darwinian evolution produce arbitrary levels of complexity from much simpler inputs in silico.

 

Do you have any links for further reading please? I'd imagine it would be an interesting read.

 

 

 

I wasn't asking whether such structures would be predicted at all, but whether the predictions could be more finely tuned.

 

It's still not entirely clear to me what you are intending to discuss and what the point of your previous posts in this thread were, but I will raise some points to hopefully improve your knowledge of some concepts.

 

 

 

So, does genetic drift result in more unique combinations of genes?

 

no. Genetic drift is the change in allele frequency in a population by chance deviation from the expected inheritance pattern, so it cannot result in a unique combination of genes as genetic drift operates on alleles already present in the population. There are however other random (some are not random) mechanisms which can result in unique combinations of alleles/genes, such as crossing over and independent assortment in meiosis for example.

 

 

 

Also, does a lower reproductive age result in greater genetic drift?

 

no, reproductive age does not impact the outcome of genetic drift at all. Though it can increase the speed at which genetic drift can act as time between generations is smaller. When you say greater genetic drift, I assume you mean greater deviation from the expected frequency. The main factor which can affect this is population size (smaller population size will on average be observed to deviate more significantly than the expected than a larger population).

 

 

 

The first variable is reproductive age. My reasoning goes like this. If the reproductive age is later in the lifespan, mutants are less likely to survive to the reproductive age. In such a situation, new mutations will be whiped out before they can appear in many generations/recombinations. On the other hand, a population with a lower reproductive age should be more genetically diverse (testable prediction!).

 

I call the second variable transitional environment. My reasoning goes like this. When the environment is changing rapidly or a new environment is being colonized, the widespread traits are no longer advantageous, thus competition is less of a problem for mutants. Thus the population will temporarily be more diverse (testable prediction!).

This is a little too simplistic, as there are important factors not considered. E.g. if during this environmental change a lot of the population die off then diversity might fall rather than increase as you claim.