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Only logical issue I see is his that in saying evolution is a theory and a fact this did not follow his pattern of things that are facts and theories. For instance, he said the existence of cells is a fact and cell theory is a reasonable way of explaining how cells function.

I guess I'm just confused because he uses the same word "evolution". It seems like this is the same thing as saying cells are a theory and a fact. But that doesn't even make sense as far as the word "cells" goes. Wouldn't it make more sense to say life is a fact and evolution is a reasonable way of explaining how life functions? Or something along those lines, I can't quite wrap my head around it. Perhaps someone can explain this more clearly?

He might just be using two definitions of the word "evolution" to make a point/sound more poetic. But this just comes off as more confusing to me.

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I think the argument towards evolution being a fact is that we have watched bacteria evolve in real time. (http://news.harvard.edu/gazette/story/2014/02/evolution-in-r...) So not only is it a good model, it happens to be elevated to the level of fact because we have directly observed it happening.

This is a termionology issue based on what "theory" actually means in science. Theory in science means a foundation of how we think things work. For example people are perfectly fine with the "Theory of Gravity" being a "Theory" although no one doubts the observable effects of gravity. In the scientific community evolution has a similar standing.

Right, and just to close the loop, it is a fact that gravity exists, and the theory of gravity is our current thinking of how it works and why it exists. Likewise, it is a fact that evolution exists, and the theory of evolution is our current understanding of how it works.

It is worth noting that a lot of people don't seem to be taught about gravitational theory in any reasonable depth in public school. Instead, most are familiar with the law of universal gravitation, which is an axiom specifically in Newtonian mechanics.

Thus much of the confusion is in people not knowing the differences between laws, theories, hypotheses and conjectures. Sloppy curricula is a large factor in this, I think.

I guess that your confusion comes from the common use of "in theory" in English (where it's often used for something that "worked in theory but not in practice".) In fact, the "theory" in science means much more than that particular use:

http://en.wikipedia.org/wiki/Theory

"A theory can be a body of knowledge, which may or may not be associated with particular explanatory models."

Evolution is a huge body of knowledge accumulated over a long time and also a fact -- we can actually observe it happening, just like we see the Sun rising every day.

Or to give you a less obvious example of the theory and the fact:

http://www.astronomy.ohio-state.edu/~pogge/Ast162/Unit5/gps....

I you'd consider the general and the special relativity as "just theories" in the sense of those who use that phrase and who typically don't understand the meaning of the word in science, since something being a theory doesn't imply what they think it implies, you couldn't use the GPS.

Calling something a theory in science doesn't imply that the science doubts that. Of course there are the unproven theories that are wild speculations, but there are those that are effectively fully confirmed.

From what I understand:

Darwin's theory of evolution (by natural selection) is called a theory because it's a possible model (maybe / maybe not directly observable), but that life forms "evolve" (undergo change) is an observable fact.

No, the "theory" means "explanation", nothing more, nothing less. Just like "the theory of gravity". Or tide - we all know what tide is and how it happens, and if you explain how it happens (physically), you might call the explanation "the theory of tides" [1].

[1] http://en.wikipedia.org/wiki/Theory_of_tides

according to my understanding, there is no "fact" in science. there are observations, hypotheses (and null hypotheses if related to stats) and theories. i think "fact" is used in the article as theories or hypotheses that explain corresponding observations well enough, and over and over again.

Observation, if verified that it's done correctly, is a fact. Evolution is actually observed, so it's a fact.