If there is a "reshuffling" (random), it still doesn't provide a cause for the mechanism called "environmental/reprodutive pressure".
Why do you bring up environmental/reproductive pressure? These terms together are part of natural selection, which, combined with mutations, leads to adaptation (evolution).
Organisms have more offspring than needed to keep their numbers constant. Offspring varies genetically. Resources are limited, thus, it comes to competition. Because of the developing 'environmental/reproductive' pressure, on average, the better equipped organisms tend to survive.
So, you see there are causes. Their occurrence cannot be random then.
They are not predicted due to our current knowlege of such causes, but they are NOT unpredictable by nature though.
Yeah, that's what I said. Like throwing a dice, you can't predict the outcome, but of course, it is somehow determined, or, if determinism doesn't apply (doesn't matter for that discussion), at least caused to fall a certain way. It still makes sense to call it 'random' though, as opposed to 'guided', we just have to agree on what is meant.
Still, this is why I say that, in the current state of our knowledge on the causes and occurrences of cosmic rays, toxic or simply assimilated ("neutral") elements... We cannot qualify the theory of evolution and NS as theories but hypotheses.
That's like saying we can't explain how a car works because we don't have an exact model of how the up quarks interact with the down quarks in the nucleus of a hydrogen atom in a gasoline hydrocarbon molecule.
1- It doesn't suffice to claim the causes of genetic mutation may be due to cosmic rays, one has to PROVE it to make it a scientific hypothesis.
Better, one has to prove and identify ALL the causes and verify if they explain ALL mutations ("naturally") occurring.
So, second point:
- They seem to don't explain ALL actual mutations... It's addressed in the course of the thread.
There's gene transfer, viral insertions and recently genetic engineering too. Other than that, I doubt there's anything else.
And if it was only a direct action of the environment, why don't we observe countless of useless or damaging mutations occurring in organisms living in their biotopes or studied "in vitro" (those occurring in-vitro are either intended by genetic manipulation or intended by exposition to high doses of radiations)?
Direct action of the environment? It's just entropy at it's work. You can't keep systems organized to perfection, sometimes errors happen. Anyway, it does happen in nature, just not as often as you think. Humans are born with on average 3 mutations. Most of time, as I said, they're all indifferent because the happen in places where the DNA doesn't even get transcribed.
Furthermore, most of the bad mutations are never noticed, because they lead to early natural abortion during pregnancy.
You're forgetting the timescale. Evolution took place for 3.5 billions of years, there need to be very few beneficial mutations per decade or even century to make a huge difference over time. And keep in mind, species consist of thousands of individuals, it may happen in any of them.
Favored by what? [Regarding beneficial mutations]
There can be no "adaptation" in an uncontrolled/unguided process. That's a logical non-sense... Or an a-posteriori constatation. We believe there has been an adptation simply because organisms are here, now and they are "adapted" to (in fact simply live in) a environment E.
By natural selection! By being beneficial, they increase the organism's chances of survival and reproduction. Thus, on average, they get passed on to the next generation more often than competing alleles. Thus, they can become, one starting out as single mutations, the norm in the gene pool. Of course, through chance events, even an invidual with great mutations can die, by i.e. getting hit by an unexpected coconut. The point is statistical, yet very real and powerful, as can be shown by computer simulations - even with very conservative assumptions.
As we believe evolution to be true, then we deduce that the organisms living today must have been the result of an adaptation. It's circular thinking.
Not how it works. Common descent is supported by overwhelming evidence in comparative anatomy, embryology, molecular comparison, DNA comparison (i.e. ERV distribution), vestigial remains, fossil evidence, evolution in action (ring species, bacteria evolving resistance, speciation events) and geographical distribution.
And you seem wrong in your interpretation of the concept of "adaptation" (above all if you couple it with the Baldwin effect as you suggest) since it seems to mean: guided change through accumulated knowledge.
Forget about the Baldwin effect. It's complicated and irrelevant in this context. I mentioned it because it accelerates natural selection. It's not needed though, it only applies in exceptional cases.
And if it was truly "random" why the genes are kept (transmitted) then??
What "decides" if this (combination of) genes is more beneficial than another??[/b][/u]
The ones that are 'kept' are the ones that manage to get passed on to the next generation. Meaning they make their 'carrier individual' mate successfully. A mutations that alters an important step in a molecular metabolism cascade by i.e. changing the 3D shape of an enzyme can have fatal consequences for the organism. The organism thus dies in infancy, and obviously, such a gene is not kept.
If however a gene has a good effect, i.e. by making the 3D shape of an important enzyme a bit more effective, this could lead to an organism that has more endurance or strenght than others, or is better at reducing it's toxine level or something, and thus, the genes has a better chance at getting passed on.
Would that mean that they can do more/better than their genome allows?
Or could that mean they can improve their own genome and therefore benefiting new skills?
No, none of that. As I said it's irrelevant for the discussion. To be honest, I had to read about it at least three times until I understood the concept. Don't worry about it, we can discuss it after you understand the rest. If you disagree with the easy stuff, it doesn't make sense to talk about something complicated.
Or should we use an other term to describe this phenomenom?
Also we must accept that the concept of "the survival of the fittest" is not predictable either, yet. Therefore NS is NOt a (scientific) theory.
I can't follow your reasoning. It is
to some extent predictable, there are some general trends in evolution that are confirmed by the fossil record (i.e. in times of lots of oxygen in the air, insects grew bigger; island dwarfism and giantism, birds losing wings on islands, animals living in cave losing their eye function, predators and prey becoming faster, life in general tending to become bigger etc..).
It all makes a lot of sense. Of course, one can't predict exactly what
, and how
it all happened/will happen. That really doesn't matter though.