You misunderstand what is a scientific theory.
The late Stephen J. Gould explains:
Evolution is a theory. It is also
a fact. And facts and theories are different things, not rungs in a
hierarchy of increasing certainty. Facts are the worlds data.
Theories are structures of ideas that explain and interpret facts.
Facts do not go away when scientists debate rival theories to
explain them. Einsteins theory of gravitation replaced Newtons,
but apples did not suspend themselves in mid-air, pending the
outcome. And humans evolved from ape-like ancestors whether they
did so by Darwins proposed mechanism or by some other yet to be
discovered.
Douglas J. Futuyma is the author of the introductory textbook on
evolution, Evolutionary Biology and has this to say:
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.
