nemesis_juggernaut writes:
I'm glad you added that element, because history is full of catastrophe's that surely would effect numerous populations and how and when they would evolve, supposing that would at all.
I only included it to allow the whole evolutionary process to get out of local minima. Without the catastrophies evolution still took place.
But you're forgetting that it's the genome that determines the organism, not vice versa. Yes, for a given organism, it's obviously true that its genome cannot be endlessly varied upon, or it would cease to be that given organism.
Well, this a chicken-egg argument I suppose.
I don't think so. The phenotype of an organism is for a large part the result of its genotype. The reverse isn't true.
But you make the distinction for me that if organisms were so prone to variabilty, we would not have the populations that we do. In fact, if evolution were true why wouldn't we see so much more variabilty than we do?
What do you mean? Isn't the variability in nature enough for you? There are about 3.500 different species of mosquitos alone. Based on that fact, can you imagine the total number of different species in the whole of nature? I know I can't.
Besides, how do you propose to calculate how much variability evolution should yield?
A ”trait’ can only be quantitative so that any move towards the objective can be selected for. Many biological traits are qualitative”it either works or it does not, so there is no step-wise means of getting from no function to the function.
To see why this is not true, please ask the nearest person with glasses whether they prefer their myopic eyes over no eyes at all.
A single trait is selected for, whereas any living thing is multidimensional. A "GA" (Genetic Algorithm) will not work with three or four different objectives, or I dare say even just two. A GA does not test for survival; it tests for only a single trait. Even with the simplest bacteria, which are not at all simple, hundreds of traits have to be present for it to be viable (survive); selection has to operate on all traits that affect survival.
Nothing stops a programmer from developing a more complex fitness function, or a set of them, all of which a candidate for survival has to pass.
Something always survives to carry on the process. There is no rule in evolution that says that some organism(s) in the evolving population will remain viable no matter what mutations occur. In fact, the GAs that I have looked at artificially preserve the best of the previous generation and protect it from mutations or recombination in case nothing better is produced in the next iteration. This has a ratchet effect that ensures that the GA will generate the desired outcome”any move in the right direction is protected.
This is a property of the evolutionary algorithms that you've looked at, but in no way a property that all of them must have of necessity.
(And this objection could be applied to your introduction of the catastrophe. I agree that such variables should exist simply because they surely exist in actual nature, however, one cannot introduce a catastrophe simply because their algorithm is no longer producing viable organisms any longer).
As I've stated above, I only included catastrophies to allow the evolutionary process to get out of local minima. I did not include them to in order to better model reality. Again, without them, evolution took place all the same.
# Perfect selection (selection coefficient, s = 1.0) is often applied so that in each generation only the best survives to ”reproduce’ to produce the next generation. In the real world, selection coefficients of 0.01 or less are considered realistic, in which case it would take many generations for an information-adding mutation to permeate through a population. Putting it another way, the cost of substitution is ignored.
Again, evolutionary algorithms are a proof of concept, not an accurate model of the whole of nature. It is of no consequence that some aspects of evolution are a bit different in reality than they are in an evolutionary algorithm, or that they are absent in them altogether. What matters is that the principle still holds, you can see evolution happening, by just implementing the basics of it's mechanism.
"Ignorance more frequently begets confidence than does knowledge: it is those who know little, not those who know much, who so positively assert that this or that problem will never be solved by science." - Charles Darwin.
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