What is science?
Dictionary.com says its systematic knowledge of the physical of material world gained through observation and experimentation.
What is theory?
Dictionary.com says theory is a proposed explanation whose status is still conjectural in contrast to well-established propositions that are regarded as reporting matters of actual fact.
It’s no secret that the Theory of Evolution is still a theory. Even as we pass Darwin’s 200th birthday, scientists have been unable to produce enough evidence to fill the holes. If someone tries to argue, “Well, it’s basically proven,” it’s not. There are important reasons it is theory.
There are gaps in the fossil record. Have you ever heard the term “missing link”? All of the links are missing. The theory attempts to reason that fossils are hard to create in nature, and uncommon enough which is why the evidentiary missing links have never been found. It is an excuse, not an explanation.
Has evolution ever been observed?
Microevolution, which is the process by which organisms adapt to their environment, is observed all the time. These adaptations are just reactions to stimulus; not evidence of macroevolution.
Macroevolution is what would cause the mutation that is still unproven.
[Warning, some sarcasm follows]
The common sparrow is highly tailored for flight. According to evolution, its nearest known relatives are dinosaurs. Somehow, the sparrow leapt to having hollow bones to make it light enough to fly. Before that, it must’ve just had wings that were the right size and shape, but couldn’t provide enough lift for flight. Even a bird as large as an albatross has a lighter skeleton than the entire weight of its feathers! The sparrow also miraculously developed a hole in its shoulder, with a new tendon to attach its wings to its breast muscles. These adaptations not found in its “closest relatives” are necessary for the sparrow to lift its wings. Before it had this hole its wings would have been completely useless. A birds eyes are so sharp, that to see like a vulture, a human would need an 8x telescope! A birds eyes are developed so that it can still spot food while flying, and often are the heaviest things in its head. A bird’s digestive system is also streamlined for flight. A diet of mainly protein (insects, etc.) allows it to have short intestines, and mostly liquid waste which crystallizes into the white substance we see so much. When a bird is standing, perched, its legs are actually crouching. Were it to stand, its muscles would automatically catapult it into flight. Could you imagine a bird needing a running start to fly?
“Are not five sparrows sold for two pennies? And not one of them is forgotten before God. Why, even the hairs of your head are all numbered. Fear not; you are of more value than many sparrows.” (Luke 12:6-7)