Yes. This is a somewhat simplified but correct explanation of mutation.I'm not an expert by in the study of DNA or evolutionary processes or even biology as a general field.
Here's link that talks about mutations.
They talk abut neutral mutations, beneficial mutations, and harmful mutations.
In particular, it says that, "Many other mutations have no effect on the organism because they are repaired before protein synthesis occurs. Cells have multiple repair mechanisms to fix mutations in DNA."
Now here you've completely jumped the rails. I don't see where you came up with this interpretation.So mutations in effect aren't really random because not all the mutations that could occur are permitted. That is a very good thing because random mutations would end up being destroying our bodies. The mutations that are allowed are those that fit into the design and the criteria of the design is not "survival of the fittest".
No mutation is "not permitted." The sequence of any section of DNA can mutate. There's nothing protecting any particular part of the chain. Some mutations are repaired, but beneficial mutations are as likely to be repaired as harmful ones. I don't know of any mechanism that prevents any particular type of mutation.
"Random" refers to the incidence and sites of mutations, not to their effects. They are random inasmuch as when and where they occur is unpredictable.
Why would random mutations destroy our bodies? How would that happen?
Harmful mutations tend to be eliminated. Beneficial ones tend to be retained. Neutral ones could go either way.
No mutations are "allowed." How did you get that from the article cited? And there is no design, and no "criteria." There's no plan. They are random.
Humans are an anomaly. The 'environment' we're adapting to is no longer a natural one. Mutations that would be harmful in other species do not impede our reproductive success. Diabetics, nearsighted people, weak or dimwitted people reproduce as successfully as anyone else, so there is no longer any selective process weeding out these otherwise harmful traits.Natural Selection is the process by which organisms better adapted to their environment tend to survive and produce more offspring. I agree that natural selection does occur, but how exactly is it occurring in people today? Are people dying before they pass on their DNA? I don't think so. But if it's true that people are not actually prevented from passing their DNA because of death, then how is the selection process actually taking place?
This isn't to say that humans aren't evolving by the same mechanisms driving the process in other organisms, it's just that different traits are being selected.
But this mechanism is still operating. What gives you the impression it isn't? It's just that there's more to it than a single mechanism.It's not happening the way that I was taught in school. Let's look at the example of the bright green beetles and the brown beetles. The birds come along and eat the bright green beetles and not the brown ones, so that results in more brown beetles and fewer green beetles. "Survival of the fittest" meant green beetles weren't reproducing. This is essentially how I was taught natural selection took place. The reality is that I was taught a model for evolution that was like trying to use a bulldozer to play Jenga!
Go back to the 'beetles' site and go through the Evolution 101 part again. Review the major mechanisms like Natural selection, genetic drift, mutation, and gene flow, and how other mechanisms like variation, sexual selection and differential reproduction play into it.
Mechanisms: the processes of evolution
Cell repair is more a physiological process than a direct mechanism of evolution. If by "negative selection" you mean simplification or elimination of previously acquired traits, this is just ordinary natural selection. Natural selection has no trajectory, it doesn't always increase complexity. It weeds out whatever impedes reproduction and selects for whatever promotes it.But it turns out that completely different mechanisms are actually involved in the process. Scientists still call it natural selection, but it isn't the same natural selection that I learned in school. We have "negative selection" and "cell repair" and a whole lot of other things going on that show evolution isn't quite so random.
I'm not understanding how you're defining "random."But let's take a step back. The OP states:
I agree: orthogenetic evolution is an obsolete biological hypothesis.
But does it make sense to me (as opposed to the theory that we are a random accident)? Yes.
Why?
1. I always found it difficult to believe that organisms around me are changing randomly.Conclusion: I can't accept orthogenesis without informative articles to support it but I am also not confident that scientists fully understand anything in the physical world that they have decided is "random". Doesn't "random" really just mean that they don't know (can't predict) it?
In fact, random mutations would devolve us.2. It turns out that there are mechanisms that prevent random changes to our DNA.
And I am unconvinced that scientists fully understand these changes.3. Any system that is sufficiently complex appears random.
i.e. the weather, pseudo-random number generators, card shuffling, die rolling, etc.
There are random mechanisms that generate variation and non-random, selective mechanisms that sort out the variation.
The major mechanisms of evolution are pretty well established, but there are always more details to sort out and new discoveries opening up new areas of inquiry.