Role of Mutations

It is a very important one. It was first pointed out by Crow and Kimura in the early 1970's that not all mutations need be beneficial or detrimental, but many can be neutral. The net effect on a population is the retention of genetic variation simply because selection does not act on it. But that is not to say it never will.We need to step back and consider that the terms 'beneficial' or 'detrimental' are rather loaded terms and often very much determined by the current circumstances that the organism encounters in its life. And circumstances change. Whether a mutation is beneficial, neutral or detrimental is sometimes very much context-dependent. For example, a gene for insecticide resistance is very beneficial to an insect when it is trying to survive in an agroecosystem with heavy insecticide usage, but the same gene is often disadvantageous (compared to alternative alleles) when the selective pressure of the insecticide is removed. So is the mutation to insecticide resistance beneficial? It depends entirely on where the organism finds itself trying to survive.

Firstly, all mutations occur 'without selective pressure' - selection is something exerted after the fact of their expression in phenotypes. But otherwise you are correct so far. Many mutations occur and then persist simply because they have no direct effect on the individual's survival - under present circumstances. However, circumstances may subsequently arise where they do affect survival, either negatively or positively. Some chemicals are mutagenic, but they typically cause random damage. Don't confuse resistance to noxious chemicals as something brought about by those same chemicals, because that's not how it works. Here you are much closer to the truth. Resistance to noxious chemcials is a result of selection by those chemicals on individuals bearing mutations that are otherwise neutral or deleterious in the absence of the chemical. However, the production of the mutation itself has nothing to do with exposure to the chemical. Precisely. Only the mutation at the locus in question would occur every generation with a particular frequency with or without exposure to the chemical. It is only consistent exposure to the chemical that causes it to increase in frequency in the population, so its not as fortuitous as you might seem to imply by saying "at just the right time".Edited by EZscience, : No reason given.

...and as such they have never been immune to natural selection, and most likely derive from 'gut-level' neural responses that had adaptive significance in survival and/or reproductive contexts.You don't need intelligence for emotions, in fact emotions are far more primitive in nature than any form of abstract thought and appear to arise in the hippocampus, one of the most primitive regions of the brain that is present even in reptiles.I think you have a few misconceptions about the nature of mutations in general that could use better clarification - Scrutinizer has covered some of this quite well, but I would say you need to work harder on understanding the basic mechanisms of mutation before you will be able to link them conceptually to higher level neural processes in a meaningful way.

Sorry - didn't mean to imply you were holding any fixed beliefs. Just trying to share my own conception of emotions as products of natural selection rather than anything resulting directly from neutral mutations.

I can't help but wonder what sort of useful insights Creationist thinking has provided for your vet-med learning experience. Surely as a vet in training, you are exposed to some biological theory. Ever wonder where all that understanding of how animals function came from? It sure wasn't the bible.