About 30 years after Darwin’s book was published evolution professor Joseph Le Conte wrote this:
Evolution is certainly a legitimate induction from the facts of biology. But we are prepared to go much further. We are confident that evolution is absolutely certain. Not, indeed, evolution as a special theory—Larmarckian, Darwinian, Spencerian—for these are all more or less successful modes of explaining evolution … but evolution as a law of derivation of forms from previous forms; evolution as a law of continuity, as a universal law of becoming. In this sense it is not only certain, it is axiomatic. …
So also, the origins of new organic forms may be obscure or even inexplicable, but we ought not on that account to doubt that they had a natural cause, and came by a natural process; for so to doubt is also to doubt the validity of reason, and the rational constitution of organic Nature. The law of evolution is naught else than the scientific or, indeed, the rational mode of thinking about the origin of things in every department of Nature. … the law of evolution is as certain as the law of gravitation. Nay, it is far more certain …
More recently, evolutionist R. C. Lewontin wrote this in a scientific journal:
It is a fact that all living forms come from previous living forms. Therefore, all present forms of life arose from ancestral forms that were different. Birds arose from nonbirds and humans from nonhumans. No person who pretends to any understanding of the natural world can deny these facts any more than she or he can deny that the earth is round, rotates on its axis, and revolves around the sun.
Evolutionist Neil Campbell wrote this in his biology textbook:
The term theory is no longer appropriate except when referring to the various models that attempt to explain how life evolves … it is important to understand that the current questions about how life evolves in no way implies any disagreement over the fact of evolution.
Here’s another example textbook example from Douglas Futuyma:
A few words need to be said about the "theory of evolution," which most people take to mean the proposition that organisms have evolved from common ancestors. In everyday speech, "theory" often means a hypothesis or even a mere speculation. But in science, "theory" means "a statement of what are held to be the general laws, principles, or causes of something known or observed." as the Oxford English Dictionary defines it. The theory of evolution is a body of interconnected statements about natural selection and the other processes that are thought to cause evolution, just as the atomic theory of chemistry and the Newtonian theory of mechanics are bodies of statements that describe causes of chemical and physical phenomena. In contrast, the statement that organisms have descended with modifications from common ancestors--the historical reality of evolution--is not a theory. It is a fact, as fully as the fact of the earth's revolution about the sun. Like the heliocentric solar system, evolution began as a hypothesis, and achieved "facthood" as the evidence in its favor became so strong that no knowledgeable and unbiased person could deny its reality. No biologist today would think of submitting a paper entitled "New evidence for evolution;" it simply has not been an issue for a century.
Even the National Academy of Sciences states that evolution is a fact. They explain that in science the word “fact” can be used “to mean something that has been tested or observed so many times that there is no longer a compelling reason to keep testing or looking for examples. The occurrence of evolution in this sense is a fact. Scientists no longer question whether descent with modification occurred because the evidence supporting the idea is so strong.”
In his book What Evolution Is evolutionist Ernst Mayr wrote:
However, throughout the nineteenth century whenever people talked about evolution, they referred to it as a theory. To be sure, at first, the thought that life on Earth could have evolved was merely a speculation. Yet, beginning with Darwin in 1859, more and more facts were discovered that were compatible only with the concept of evolution. Eventually it was widely appreciated that the occurrence of evolution was supported by such an overwhelming amount of evidence that it could no longer be called a theory. Indeed, since it was as well supported by facts as was heliocentricity, evolution also had to be considered a fact, like heliocentricity. …
Evolution is a historical process that cannot be proven by the same arguments and methods by which purely physical or functional phenomena can be documented. Evolution as a whole, and the explanation of particularly evolutionary events, must be inferred from observations. Such inferences subsequently must be tested again and again against new observations, and the original inference is either falsified or considered strengthened when confirmed by all of those tests. However, most inferences made by evolutionists have by now been tested successfully so often that they are accepted as certainties.
Mayr also concludes:
It is very questionable whether the term “evolutionary theory” should be used any longer. That evolution has occurred and takes place all the time is a fact so overwhelmingly established that is has become irrational to call it a theory. …
Evolution is not merely an idea, a theory, or a concept, but is the name of a process in nature, the occurrence of which can be documented by mountains of evidence that nobody has been able to refute. Some of this evidence was summarized in Chapters 1-3. It is now actually misleading to refer to evolution as a theory, considering the massive evidence that has been discovered over the last 140 years documenting its existence. Evolution is no longer a theory, it is simply a fact.
And in his book Why Evolution is True, evolutionist Jerry Coyne writes:
Now, when we say that “evolution is true,” what we mean is that the major tenets of Darwinism have been verified. Organisms evolved, they did so gradually, lineages split into different species from common ancestors, and natural selection is the major engine of adaptation. No serious biologist doubts these propositions.
These are representative quotes of the evolutionist’s consensus position. It would be difficult to find more obvious examples of misrepresentations of science.