Naked Science Forum
General Science => General Science => Topic started by: neilep on 19/04/2008 17:21:43
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Dear Evolved Peeps,
Evolution is my all time favourite process of growth and development:
Look, here it is before your eyes .
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Now that's quality evolution !
But, akin to a climate model that predicts the weather.........knowing the lifestyles and cultures and circumstances of peeps and stuff around the world.......can we, or are there any evolution models available ?...for any species ?...of flora and/or fauna ?
Whajafink ?
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LOL LOL LOL
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Your association with climate modelling implies that you are not merely talking about system that can model evolutionary processes in the abstract, but specifically a system that can model animal evolution on Earth.
The problem with this is ofcourse that we ourselves are part of the animals system on Earth, and so we would need a system that can model humankind itself. This leads to the problem that would this model have to contain within it a model of human beings trying to model themselves?
OK, the above may be a little facetious; but the underlying problem is that if we are trying to model the human component of animal evolution, and if that model then predicts that humankind will be wiped out by some particular cause, then we use that knowledge to avoid being wiped out by that cause, then we will have invalidated the model.
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*restrains from turning this into another creationism vs evolution debate*
Im pretty sure there are models out there, but I wouldn't know from where
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Is there a Hari Seldon in the house?
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since evolution is driven by random mutations, and you have no way of know which of tehse random mutations will occur, there is no way to accurately predict which way evolution will go.
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since evolution is driven by random mutations, and you have no way of know which of tehse random mutations will occur, there is no way to accurately predict which way evolution will go.
I don't think the above is true on two counts.
Firstly, most of evolution is not driven my random mutation (i.e. the creation of new genes), but by remixing of existing genes (e.g. their is always natural diversity within any species, but evolution will give advantage to some variants of that diversity, and disadvantage to other variants of that diversity, without there having to be any actual new genetic material created).
But, even with regard to newly created genetic material; there are many mutations, most of which will simply be maladaptations and will perish. So the question is whether the limiting factor is the insufficiency of mutations, or the restrictions that the current environment will at any given moment in time place upon which adaptation with thrive. If it is the latter, then although one may not say with absolute precision when a particular mutation will occur that will take advantage of a change in the environment, but one can say with some predictive capability what types of mutations would be allowed to survive in that environment, and thus assume that sooner or later such a mutation will naturally occur, and sooner or later it will be allowed to survive.
In my view, the limiting factor is not in finding a mutation to fit the environment, but in trying to understand the environment well enough to know which mutations would survive.
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you are correct that there are many other types of genetic changes that may come about other than point mutations. I believe that you could still classify these as mutations, but regardless; my point was that no matter how much you understand about how the environment is going to change, there is no way of knowing what genetic variation is going to be present to adapt to it. There are SOME very complicated ways of calculating some of the more probable genetic arrangements to occur. So I guess this could address Neil's original question, but i compared to a weather prediction model, such a model to predict evolutionary trends would be much more complicated and much less accurate. Now just think how much effort they put into predicting the weather and how inaccurate they usually are. Is such a model really useful??
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my point was that no matter how much you understand about how the environment is going to change, there is no way of knowing what genetic variation is going to be present to adapt to it.
I think the counter argument to this is the prevalence of convergent evolution - where you have in different localities, but similar environments, different species that perform the same roles - so while you cannot predict which species will take on a particular role, you can predict that there will be some species, of whatever family, that will perform a specified role in the environment, and you will be able to say some things about what that species will look like in general terms (as dictated by the function it performs).
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yeah, convergent evolution was the first thing that came to my mind when i first read neil's question. however, there are so many more examples where convergent evolution DIDN'T happen than when it DID, that its really the exception to the rule. I don't think you could conclude from the fact that isolated species adapt the same traits SOMETIMES gives you the power to predict what will happen in the future. Even if convergent evolution was the rule rather than the exception. It still doesn't give you any predictive powers when it comes to new environmental conditions that have not been experienced by any historical organisms.
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umm.... [::)]
*restrains from carrying over a debate from another thread* [;)]
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Firstly, to clarify, I am not trying to suggest that we can predict what evolution will do; all I am trying to suggest is that personally my own naive belief is that it is not the 'randomness' of mutation that is the limiting factor but rather the unpredictability of the environment (both the macro environment and the micro-environment).
My own view of the role of mutation in evolution is rather like regarding mutation as white noise, and evolution is a filter that selects specific frequencies from that white noise. Although white noise is inherently random, but is also contains such a wide range of possibilities, that it really provides very little restriction on what the final output might be, but it is the filtration process that actually shapes the output.
In that respect, it is the micro-environment through which the white noise of mutation is filtered that shapes the direction of evolution. The problem is that micro-environment is itself inherently chaotic.
As an artificial (but therefore, manageably simplified) example - look at artificial breeding programs. Artificial breeding programs rely on random mutations (if one takes the wider definition of mutation, not merely point mutations), but enforce an artificial environment which filters those mutation. Despite the randomness of the mutation process, the filtration process is what determines the direction of genetic change - so if you filter for a bigger breed of dog, no matter what random mutations you will get, you will finally select for a bigger dog.
The original term 'natural selection' was intended to create an obvious analogy with 'artificial selection' - as both processes were seen as analogous.