You are mistaken because "theory" in scientific
parlance differs from its meaning according
to layman use.
Evolution is both a theory and a fact. When scientists use the
word "theory", they do not mean "guess"- it means a body of
knowledge based upon sound evidence.
From Scientific American at: http://www.sciam.com/article.cfm?articleID=000D4FEC-7D5B-1D07-8E49809EC588EEDF
Many people learned in elementary school that a theory falls in
the middle of a hierarchy of certainty--above a mere hypothesis but
below a law. Scientists do not use the terms that way, however.
According to the National Academy of Sciences (NAS), a
scientific theory is "a well-substantiated explanation of some
aspect of the natural world that can incorporate facts, laws,
inferences, and tested hypotheses." No amount of validation changes
a theory into a law, which is a descriptive generalization about
nature.
So when scientists talk about the theory of evolution--or the
atomic theory or the theory of relativity, for that matter--they
are not expressing reservations about its truth.
In addition to the theory of evolution, meaning the
idea of descent with modification, one may also speak of the
fact of evolution. The NAS defines a fact as "an
observation that has been repeatedly confirmed and for all
practical purposes is accepted as 'true.'" The fossil record and
abundant other evidence testify that organisms have evolved through
time. Although no one observed those transformations, the indirect
evidence is clear, unambiguous and compelling.
All sciences frequently rely on indirect evidence. Physicists
cannot see subatomic particles directly, for instance, so they
verify their existence by watching for telltale tracks that the
particles leave in cloud chambers. The absence of direct
observation does not make physicists' conclusions less certain.
i know wot theory scientifically is lol....
these topics has been goin one since i dun remember
when.......
dunnit to teach me......
i didn't say theories are guesses......guesses are guesses and
theories are theories.....
in the end, everything in this world are considered
theories........theories are proven to the best of knowledge....but
sometimes that best of knowledge is not good enough....its just
like the laws of gravity which have been over the times been more
understood better....thats why i said it is up to each
individual.......