If it's passed to one offspring, that offspring may have two offspring, and those two may have two more, and it spreads exponentially. Some genes have a larger chance of transmitting than others, it may always be transmitted (dominant or recessive). Given time, the entire population could be the offspring of that first person where the mutation occurred. Of course, this is with the gene having a neutral effect. It's of course much greater if that gene confers a survival or reproductive advantage.Then let me rephrase my question. How then can that 1 random mutation, that affected 1 individual only, be expressed to the population of a whole that follows? I don't see how that is possible -- to randomly pass it down to descendants and it expressed to the population as a whole. Please tell me the mechanics of that.
Think of the mutation as one that effects the expression of a gene (though I don't know if that is possible). Counting in a mate there is only a 50% possibility that mutation gets passed on to a descendant, but counting 2 copies each of the gene, a 25% chance. That is not going to get expressed to the population as a whole to where everybody has that mutation.
Without.Is that with or without an isolation event happening?
I think most evolution happens as adaptation to disease. I don't know about viruses actually causing the mutations, but I'm not a scientist.Most of this has been about random mutations. What about non-random mutations? For instance viruses. It appears to me they could pass along quite a bit of genetic material to the host. And, it wouldn't be just 1 random individual, but large segments of the population that recovered somewhat from the illness. If this could be a driver for evolution, it appears to me it could make some changes very fast.