to further explain what you have said let me add in lay mans term
Mutations are generally assumed to be materials of evolution.
Evolution absolutely depends on mutations because this is the only way that new alleles are created.

But this seems paradoxical because most mutations that we observe are harmful (e.g., many missense mutations) or, at best, neutral, for example:

"silent" mutations encoding the same amino acid many mutations in noncoding DNA (e.g. "junk" DNA).

most mutations affect a single protein product (or a small set of related proteins produced by alternative splicing of a single gene transcript) while much evolutionary change involves myriad structural and functional changes in the phenotype.

So how can the small changes in genes caused by mutations, especially single-base substitutions ("point mutations"), lead to the large changes that distinguish one species from another?

These questions have, as yet, only tentative answers

And you might have begun by saying that evolution is a fact but as you have just said
Scientists use 'theories' to plug these gaps based on what we know to be true

Remind u again theories

that all i am saying