[Virginia-American]

In common usage, gravity is interchangeable as both hypothesis and observation. There's no denying that variation exists within species, just as there's no denying that if I hold my hand out and drop a penny, it will accelerate downward. Both observations are true and self evident.

The hypothesis of common descent, like ...

You're forgetting some other crucial observations that Darwin's theory explains.

First is the Law of Faunal Succession, the fact that a particular fossil organism is restricted to certain strata, and the more recent fossils more closely resemble living animals and plants. This is evidence of descent within lineages, if not complete common descent.

Another data set that Darwin used was the geographic distribution of species and fossils. Wegener cited some of this in his continental drift hypothesis, now part of plate tectonic theory.

Yet another thing Darwin considered was the experience of animal and plant breeders.

[csense]

What I object to is this notion that the apple falls from the tree, therefore, evolution must be true

Maybe such people should contact the ad agency for guinness beer:

character 1: "I've just found a way to prove the theory of evolution using only a coin and the force of gravity."
character 2: "...prove the existence of evolution at the drop of a dime! BRILLIANT!!"