All right, Cyrus, clearly you accept that evolution occurs. No one can deny that. As selfAdjoint pointed out, we can observe evolution both in the lab and in nature. What we cannot observe is evolution that occurred in the past. But consider this: there are three ways that I can come up with to explain the fossil record.
1. Older species evolved into newer species. How they evolved does not matter. Perhaps it was random, perhaps it was directed by some intelligent force. Either way, they evolved.
2. Each species was individually created from scratch.
3. The entire planet was created in such a way as to make it appear that evolution took place when it fact it did not. In effect, God simply planted the fossils where they are and placed a certain ratio of radioisotope:daughter element in the surrounding rock to fool us.
Let's evaluate these options. Number 2 has a slight problem. We have observed speciation take place, both in the lab and in nature. We have seen one species become two, through nothing more than natural processes. Given that this is the case, we can at least that these species we have observed coming into existence were not created. Given this fact, scientific induction dictates that this is the method by which all species come into existence.
It may be true that inductive reasoning does not produce absolute certainty. We are moving from the specific to the general here, but that is the way science works. We have measured the force of gravity so many times and every time it can be expressed by the equation F = G \frac{m_1 m_2}{r^2}, so we induce that this equation will always hold under the circumstances in which it was derived. It's the same way with evolution. We observe it happening on this planet, operating according to a principle of environmental pressures selecting for certain allele frequencies within a given population. We observe new species coming into existence by this process, so we conclude that all species on this planet, which possesses the same variability for the same reasons and which face the same environmental pressures, come into existence naturally through a process of evolution. If you will not believe this, then in order to be consistent, you must reject all scientific theories, all of the conclusions come to on the basis of independent verification by many researchers working in many labs, including all of the equations of physics. You can't even believe that gravity will continue to hold you to this planet. The simple fact that it always has is not proof enough that it always will if you do not accept the principle of scientific induction.
Now let's look at number 3. If you believe this, I have nothing to say to you. This hypothesis is neither falsifiable nor verifiable, even in principle. It is factually meaningless.
Then we have number 1. Countless lines of evidence in countless fields of research all point to this one conclusion. All of the modern principles of the biological sciences are built on the fact that organisms evolve by the mechanism of natural selection.
Which explanation would you accept, Cyrus? Which do you think any reasonable, sane person would accept?
