There are conserable limitations to what science can do in the area of evolutionary theory:
The scientific method is limited to what can be observed with the five senses.
If something can be seen, heard, touched, smelled, or tasted, then science can deal with it. But to expect science to investigate something in the proverbial "sixth sense" is to demand too much of the scientific method, and lays it open to charges of abuse or misuse.
The scientific method is limited to the present. That science is limited to the present should be a self-evident, axiomatic truth, since the present is the only place and time in which the five senses operate. And.......that's how faults develop.
Science seeks to explain the behavior of that which is, and to check its explanation by means of experiments. But this experimental requirement can be met only in the present time. The past, and especially the beginning of things, lies beyond the grasp of this method, and so science can only speculate about the origin and history of the world . To require science to make factual statements about pre-history is to prostitute the method.
Since science is based upon observation, it must limit its scope to human history, where things can be properly observed and recorded. In recent years, there has been considerable disagreement between creationists and evolutionists over whether or not science should be limited to the present. Evolutionists have insisted on using science in an attempt to study various aspects of their theory (e.g., the Big Bang, the origin of the Solar System, etc.) that they freely admit belong in "pre-history." Creationists have responded by suggesting that such events are not observable, and therefore are not properly within the domain of science. Yet there are certain things about both evolution and creation that can be tested. In order to distinguish the things within each model that can be tested from those that cannot, some authors have suggested that science itself be divided into two categories.
operation science vs. origin science
Operation science deals with regular, recurring events in nature that require natural causes (eclipses, volcanoes, reproduction, etc.), while origin science deals with singularities that may or may not require a natural cause (the Big Bang, creation, etc.). The term "origin science" may be new, but it operates by the standard principles of causality and uniformity. The principle of causality says that every material effect must have a prior, necessary, and adequate cause. The principle of uniformity (or analogy) states that similar effects have similar causes. In other words, the kinds of causes that we observe producing effects today can be counted on to have produced similar effects in the past. What we see as an adequate cause in the present, we assume to have been an adequate cause in the past; what we see as an inadequate cause in the present, we assume to have been an inadequate cause in the past.
The origin of the Universe, and of life itself, occurred in the distant past under conditions not necessarily experimentally reproducible and therefore not able to be studied in a strictly scientific manner.
Our theory of evolution has become one which cannot be refuted by any possible observations. Every conceivable observation can be fitted into it. It is thus "outside empirical science" but not necessarily false. No one can think of ways in which to test it. Ideas, either without basis or based on a few laboratory experiments carried out in extremely simplified systems, have attained currency far beyond their validity. They have become part of an evolutionary dogma accepted as part of training
Thus, even defenders of evolutionary theory have admitted that their theory is "outside of empirical science." Of course, evolutionists have responded by suggesting that "creation is based on supernatural processes in the past" and therefore is not scientific. However, the "supernatural" beginnings of creation are no less available for scientific examination than are the "prehistoric" (though allegedly natural) beginnings of evolution. To the unbiased observer, that would seem to put creation and evolution on equal footing, scientifically speaking.
The scientific method is limited to telling us "how" a process works, not "why."
The scientific method is incapable of dealing with the realm of purpose. It can deal with cause and effect relationships; or as some would say, it can deal with the succession of events in time. It cannot deal with the "why" when one uses the term "why" with reference to purpose. Science deals with mechanism, not purpose. "Why"-in regard to purpose-is not a question science is equipped to answer.
The scientific method is limited in that it is amoral (non-moral).
Science is ignorant of values. There is nothing inherent in the scientific method that provides for the definition or study of morals. It should be recognized that science is incapable of making value judgments about the things it measures. Many men on the frontiers of science are realizing that there is nothing inherent in science to guide them in the application of the discoveries they make. There is nothing in science itself which will determine whether nuclear energy will be used to destroy cancer or to destroy cities. This is a judgment outside the scientific method to determine.
This is not meant to imply that scientists work without morals or values. It is simply to say that whatever morals or values they possess were not derived from the scientific method. Science is not equipped to deal with morals. The scientific method is limited in that it cannot deal with the unique. The scientific method deals with those things that are: (a) timeless; (b) universal; (c) dependable; and (d) repeatable. Those things that do not fit in these categories are outside the realm of science.
One-time events on earth are outside of science. The core of scientific method or methods is experimental repeatability or reproducibility. The important distinction between science and those other systematizations (the arts, philosophy, and theology) is that science is self-testing and self-correcting. The testing and correcting are done by means of observations that can be repeated with essentially the same results by normal persons operating by the same methods and with the same approach.
This explains the limits of evolution as a science. Evolution can be used as science in some areas. In other areas it is pseudoscience. In general it is just the stinky garbage of last night's party before the cleaning people have arrived.