Note that "large, encompassing" scientific theories typically **include several theoretical laws in the proposal** which may or may not be proved over time. For example: the theory of gravitation originally proposed several things that are now accepted as established, scientific laws (i.e. "the laws of gravity") ...but the theory of gravitation itself **still remains a theory** despite the fact that it includes several well-established scientific laws.
-
Riley say: Evolution is a fact. HOW evolution works is called the theory of evolution through natural selection. A law covers one thing, whereas a scientific theory covers many subjects. The theory of evolution is true in all of biology, geology, and psychology.
-
Peter say: It's becuase there is insufficient evidence to make it an absolute fact.
-
The Turin Shroud Is Fake say: A scientific law does not describe a mechanism or explanation of a phenomena. A scientific theory does.
Scientific laws tend to be rather specific, and can often be described with a mathematical equation. The mechanism of, and many influences on evolution are too complex to be described in a single equation, hence it is referred to as a theory.
Another thing to remember is a scientific law is neither better nor more accurate than a scientific theory.
-
Moose say: A theory is nothing but the best explanation there is for an observed phenomenon it only becomes a fact when it is demonstrated. In the case of evolution; if mutations happens followed by separation (not necessary) then natural selection (making the organism with the expressed form of the mutation dominant) and it happens that the mutant could not procreate with the other group (non mutant/original or with a different kind of mutation) to give viable offspring- then and only then evolution is said to have happened.
The above has not been witnessed in nature but the following has been or not been observed but in isolation: