PBS confidently instructs us that “evolution happens.” But should that matter? Even Darwin’s scientific critics agree that evolution happens. PBS is introducing equivocation into the discussion by failing to clearly define “evolution.”
Some use “evolution” to refer to something as simple as minor changes within individual species that occur over short periods of time (Evolution #1).
Others use the same word to mean something much more far-reaching, such as claiming that all living organisms are descended from a single common ancestor (Evolution #2), or that natural selection has the power to produce all of life’s complexity (Evolution #3).
Used one way, “evolution” isn’t controversial at all (i.e. Evolution #1); used another way, it’s hotly debated (i.e. Evolution #2 or Evolution #3). Used equivocally, “evolution” is too imprecise to be useful in a scientific discussion.
When you see the word “evolution,” you should ask yourself, “Which of the three definitions is being used?”
Critics of neo-Darwinism today usually take issue with Evolution #2 or Evolution #3. But the discussion gets confusing when a Darwinist takes evidence for Evolution #1 and tries to make it look like it supports Evolution #2 or Evolution #3. Proponents of Darwinism, including PBS, commonly pull this “Evolution” Bait-and-Switch, using evidence for small-scale changes, such as changes in the sizes of bird beaks (Evolution #1) and then over-extrapolating from such modest evidence to claim that it proves Darwin’s grander claims (Evolution #2 or Evolution #3).
Some of the above discussion is adapted from Explore Evolution.