You conveniently left out the word "generations," which was clearly stated in my original post (copied below):
So exactly how many generations do I have to go back before I have a monkey in my family tree? Ten thousand? A million? There is no evidence of human beings existing that far back.
1 million generations is 20-22 million years.
At what point will human beings evolve into an entirely new, more advanced species? Your genetics are determined at conception as a result of the combinating of your parents' DNA, and at no point in your life will your DNA be altered by the surrounding environment (notwithstanding radiation and cancer, which have a reverse, or devolutionary effect).
Children's DNA is a combination of parents' DNA. Carried forward a million generations, any offspring's DNA will STILL be a product of the parents' genetic mixing.
If evolution is responsible for the creation of new species, what is forcing the mutation of genes to produce new species, and why haven't we seen any evidence of it yet?
Part of your conceptual difficulty with the issue of evolution is revealed by your choice of words "...at what POINT will human beings evolve..." and "...genetics are determined AT conception...". This reflects a lack of understanding of the continuous nature of biologic phenomena. The statements would be more insightful if they were phrased as "...how is the PROCESS of human evolution manifest..." and "...genetics are determined DURING conception...".
There may, but need not be, and it would seem unreasonable to expect, that a new species would originate in one generation. There are many genes that need to be expressed in the reproductive process. By the time enough changes are made to constitute a new species, there may no longer be an survivors of the previous species, especially if the gene pool remains mixed.
Children's DNA is a combination of parents' DNA. Carried forward a million generations, any offspring's DNA will STILL be a product of the parents' genetic mixing.
As you've alluded to above, there are documented means of changing the genetic material to something other than what the parents supply. There is no requirement that point mutations be deleterious, as you suggest, which is why mutation is usually theorized to be the means of creating entirely new genes. Their rarity is why this theory is favored by large numbers of generations (both serial and in parallel--i.e. large populations).
Statistically, point mutations are unlikely to be expressed at all. If they are expressed, they are likely to be deleterious. However, natural selection is the bias against traits deleterious for a particular environment and in favor of traits advantageous for an environment. So, new advantageous traits needn't be common, since nature favors them when they occur.
If evolution is responsible for the creation of new species, what is forcing the mutation of genes to produce new species, and why haven't we seen any evidence of it yet?
A great question. The causality in your wording again seems to reveal a conceptual difficulty. You ask "what is FORCING the mutation of genes to produce a new species...?" Of course the appropriate way to view the process is that there is a sea of phenotypic changes in a changing biological system, some of which favor greater reproduction than others. That is, the only FORCE involved comes from predators, disease, the elements, and other factors of nature that lead to a creature's death before it can reproduce. The more genetic variability there is within a population, the more likely there will exist traits conducive to survival within an environment.
The other part of your question alludes to how those phenotypic changes occur. It is well documented in living systems that genetic changes, whether recombination or mutation, can produce phenotypic changes. Recombination and mutation are not well understood and are frequently modelled as random processes. Physical phenomena, such as ionizing radiation, can cause point mutations, and so there are theories about radiation sources, like cosmic rays, affecting the rate of genetic change in an ecosystem.
In the end, there are many observed facts which any theory needs to explain, such as:
(1) Physical (and therefore biological) phenomena above quantum scales are continuous.
(2) For all species, and indeed all life on earth, there was a time before it existed and a time after it existed.
(3) A creature's reproductive success is affected by its environment.
(4) A creature's reproductive success in a particular environment is affected by its expressed traits.
(5) Many expressed traits are genetically determined.
(6) Offspring usually express some different traits than their parents.
(7) Genetic mutations occur.
(8) Different species alive today express common traits and common genes. In some species those traits appear to have no function.
(9) The fossil record is a series of snapshots in time.
(10) The fossil record shows examples of temporal series of morphologically similar creatures.
There is (and always will be) much to be explained, but it is understandable why evolutionary science dominates efforts to explain current biological diversity and the fossil record.