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That's not how Evolution works. It's not a positive or negative. It's also not focused or targeted like you seem to suggest. It's random, chaotic, and unfathomably minute in it's possible chances for beneficial by product. Not to get outside my own depth here, but minor mutations occur without ever causing any benefit/negative consequence. We have adapted enough in our environment to not worry about Red hair, or Green eyes, purple eyes, or even physically prohibitive things such as shortness, obesity, brittle bones, Sickle Cell, etc.

By your logic, if I follow it correctly, they would kill any deformity not directly beneficial. Thus making "Evolution" not really a thing.

FezzikDaBullgryn wrote:
That's not how Evolution works. It's not a positive or negative. It's also not focused or targeted like you seem to suggest. It's random, chaotic, and unfathomably minute in it's possible chances for beneficial by product. Not to get outside my own depth here, but minor mutations occur without ever causing any benefit/negative consequence. We have adapted enough in our environment to not worry about Red hair, or Green eyes, purple eyes, or even physically prohibitive things such as shortness, obesity, brittle bones, Sickle Cell, etc.

By your logic, if I follow it correctly, they would kill any deformity not directly beneficial. Thus making "Evolution" not really a thing.

Mutation and evolution are not the same thing. Mutation is one of the mechanisms that allows evolution.

Evolution by natural selection is about the selective pressures on gene frequencies. If a gene has no negative or positive impact on an organism's survival, no selective pressure is applied. You are now talking about the phenomenon of genetic drift, which is the frequency of genes in a population due to random chance (ie due to reproductive probabilities or unlikely events that are not selective pressures - being struck by lightning for example).

Genes that have no impact on survival and reproduction can passively accumulate, mutate or disappear due to genetic drift. They will continue to do this until they mutate into something that does have an impact on survival, and then selection will act on them.


Your examples of human traits that don't affect our survival include some that do, but which have been offset by other traits (the plasticity genes of our neurons that allow us to think up artificial compensations for sickle cell or brittle bones). So long as our mental genetics allows us to solve failings of our physical genetics, we will continue to consider those traits benign. If at any point we develop mutations that are beyond our mental capabilities, they will have direct selective pressure on our gene frequencies through attrition.

FezzikDaBullgryn wrote:
That's not how Evolution works. It's not a positive or negative. It's also not focused or targeted like you seem to suggest. It's random, chaotic, and unfathomably minute in it's possible chances for beneficial by product. Not to get outside my own depth here, but minor mutations occur without ever causing any benefit/negative consequence.

Well, most mutations don't become heritable and many are no-goes from the start. The mutations have to be in gametes (sperm and eggs in mammals) to be passed on, and the mutation has to not affect the chance of the gamete actually undergoing fertilisation. If a sperm is physically defective, for example, it is unlikely to ever reach an egg.

We have adapted enough in our environment to not worry about Red hair, or Green eyes, purple eyes, or even physically prohibitive things such as shortness, obesity, brittle bones, Sickle Cell, etc.

Wut? Those are some odd examples there. Short people actually have longer life expectancy unless it is associated with a significant genetic disorder. Obesity is largely an environmental disease not genetic (although it does have some heritability) and being able to store energy in times of surplus is an advantage outside of the current era of plentiful energy-rich food for many. Brittle bones are not typically a genetic condition in humans- diet, age, sex, and hormonal causes are by far the commonest causes. Sickle cell anaemia is genetic, but the regions it is common have endemic malaria- sickle cell protects against malaria. So there is a positive pressure that outweighs the negative pressure in parts of Africa.

By your logic, if I follow it correctly, they would kill any deformity not directly beneficial. Thus making "Evolution" not really a thing.

You are speeding up the timeframe too much. Most traits that have negative selection pressures will take a very long time to be eliminated. Many generations. In that timeframe, it is also possible for the environment to change and start selecting for the trait again too.

 Hellebore wrote:

FezzikDaBullgryn wrote:
That's not how Evolution works. It's not a positive or negative. It's also not focused or targeted like you seem to suggest. It's random, chaotic, and unfathomably minute in it's possible chances for beneficial by product. Not to get outside my own depth here, but minor mutations occur without ever causing any benefit/negative consequence. We have adapted enough in our environment to not worry about Red hair, or Green eyes, purple eyes, or even physically prohibitive things such as shortness, obesity, brittle bones, Sickle Cell, etc.

By your logic, if I follow it correctly, they would kill any deformity not directly beneficial. Thus making "Evolution" not really a thing.

Mutation and evolution are not the same thing. Mutation is one of the mechanisms that allows evolution.

Evolution by natural selection is about the selective pressures on gene frequencies. If a gene has no negative or positive impact on an organism's survival, no selective pressure is applied. You are now talking about the phenomenon of genetic drift, which is the frequency of genes in a population due to random chance (ie due to reproductive probabilities or unlikely events that are not selective pressures - being struck by lightning for example).

Genes that have no impact on survival and reproduction can passively accumulate, mutate or disappear due to genetic drift. They will continue to do this until they mutate into something that does have an impact on survival, and then selection will act on them.


Your examples of human traits that don't affect our survival include some that do, but which have been offset by other traits (the plasticity genes of our neurons that allow us to think up artificial compensations for sickle cell or brittle bones). So long as our mental genetics allows us to solve failings of our physical genetics, we will continue to consider those traits benign. If at any point we develop mutations that are beyond our mental capabilities, they will have direct selective pressure on our gene frequencies through attrition.

Another layer of complexity is that a single property we have might be the result of several genes working together. Those genes might have beneficial and negative traits attached to them. As a result an overall beneficial property that is preserved generation to generation might well come with negative elements attached to it which don't get selected out because they have less impact than the benefits of those genes. It's the whole "You don't have a gene for a big nose, you have a multitude that result in the promotion and growth of a large nasal system"

And as noted, environment has a huge impact on what we perceive as beneficial and detrimental properties. What can be a benefit in modern life in one culture can be a negative in another. This is even more true when some are totally neutral elements (as we see them) such as eye or hair colour.

FezzikDaBullgryn wrote:
There is no "naturally evolved Species" like the Nids. It would be impossible by the laws of evolution. It would be like saying a "Dark Sun" or a "Dry Puddle". Nothing would "Evolve to naturally destroy itself. It's fairly clear the nids are a weapon gone amuck. The End state of evolution is the best possible off spring, while co-existing in the natural order of it's ecosystem. The end state of the hive mind fleets is the total destruction of all not life not part of itself, as food. It's kind of a mockery of the Necrons. Nids are to Necrons what Dark Eldar are to Eldar. A Pervsion of the same idea, dialed to 11, in the complete opposite direction.

As has been posited above, if a species evolves a natural ability to alter itself, then as soon as it becomes sentient in some way, then it can learn to direct that ability. The natural/undirected bit only needs to take them so far along the process, then they can start altering themselves consciously.

There is no end state to evolution, as the universe is not a static system. Something will always be changing somewhere that will lead to new pressures. Its not so much that the 'nids view everything as food. They are not about destruction, but about assimilation.

While a bio-weapon gone wrong is the easiest answer, I do quite like the idea of them basically as a disaster coming from a natural source.

I like the Eldar comparison. Elegant.