I really don't have much to add to what I said. But, to clarify, expound, and add a few more keystrokes: the western scientific method doesn't claim to define reality. Instead, it investigates phenomena by following a format of hypothesis, prediction, experiment, observation, conclusion. Even JK's example (of when the earth was flat) was merely a conclusion based on certain evidence, such as the human eye's line of sight and ships disappearing at sea. Other scientists of the same era used celestial evidence to determine orbits around the sun. When the so-called Dark Ages were over, former flat-earth scientists were free (of Roman church restrictions) to observe the heavens, so their conclusions changed.
Even if we say the obvious: "reality is reality!" once an observation is subjected to the scientific method, the explanation for reality can change. Add to that the limitations on observations due to space and time, and scientific knowledge becomes seemingly arbitrary.
All that pig/chimpanzee business was just some maverick scientist questioning the discrepancies of evolutionary theory, such as the fact that humans are hairless like pigs, not hairy like primates. Observation of evolution is flawed by time - none of us were there when evolutionary branches occurred - so we are unable to define "reality" as if we actually observed the event happening.
