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.
I understand the continuous nature of bioligical adaptation. However, there is no real evidence to suggest that evolutionary processes occur during any creature's life. I am the same person I was twenty years ago, and I will be the same person twenty years from now. My children's DNA has not evolved, nor has their future mates' DNA evolved.
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...".
The statements were perfectly insightful as they were written. The PROCESS of human evolution manifests itself through behavioral adaptation and mate selection across a very wide gene pool. There is no PROCESS of inter-species evolution, even if your theory is applied across millions of generations.
You have started with a conclusion (evolution explains our existence), and you're trying to match the evidence to your conclusion. The problem is your evidence consists entirely of fossil records and biological function similarities across multiple species. There is no hard science to show how one species changes into another species.
If you are saying that evolution does not demonstate itself by physical changes developing during the lifetime of an individual, you are correct. That was the basis of the now discredited "inheritance of acquired traits" theory of Lamarck
If you are saying that your biological makeup has remained unchaged for 20 years and will remain so, take a 20 year old photo of yourself and compare it to what you see in the mirror.
As for "20 years from now", one of your cells may mutate into a cancer cell three years from now in which case you may be dead 10 years from now. That cancer may be due to some carcinogen, such as a chemical or radiation, which has altered the DNA in some of your cells. So, no, you are not the same individual that you were 20 years ago. Your physical body has changed with age and your DNA has also changed with age.
My children's DNA has not evolved, nor has their future mates' DNA evolved.
DNA is constantly being damaged and constantly being repaired. DNA is constantly being copied, sometimes perfectly and sometimes not. That is a biological fact of life.
A DNA mutation is, essentially, a "Typo" during copying.
For your DNA never to mutate, you would need perfection in every DNA replication in your lifetime and no biological system is capable of such perfection.
How can you claim to understand, and to have once been an evolutionist, and yet make such a statement? It reveals your ignorance. Individual creatures do not evolve by any contemporary evolutionary theory.
The statements were perfectly insightful as they were written.
Not if you truly believe that evolutionary theory requires such a thing as a "point" of evolution.
The problem is your evidence consists entirely of fossil records and biological function similarities across multiple species.
At least you finally admit that there is evidence. Fossil evidence shows a time before humans existed. Additional evidence is the ubiquitous observation of space-time continuity. So, there was some continuous process between no human and human. If you have a nonevolutionary theory to explain these facts, let's hear it.
There is no hard science to show how one species changes into another species.
Here again you are wrong--or rather, it completely depends on how you wish to define "hard" science. Evolutionary change can be observed experimentally in creatures that can be manipulated in large populations with short generations. Fossil evidence, of course, can only give us snapshots in time, but many of those snapshots appear to fall along a continuum of change from one species to another. Genetic similarites across different forms of life is explained most simply by common ancestry and more extensive expression of those changes that are observed experimentally.