Presto, Change-o

How do we really know that one species evolved into another?
"How do we know that evolution is really happening?"

One of the factors that drives skepticism about the process of evolution (outside of a religious conviction of humanity holding a special, divinely-ordained place in the Universe and/or that only a creator deity can be a source of ethics) is the idea that it entails one lifeform "turning into" another lifeform. This can conjure up an image of change that takes an entire population, and over time, transmogrifies them, in a coordinated fashion, into a population of entirely different lifeforms. And one of the things that can help drive that misconception is the way laypeople talk about evolution.

Now, I say this as a layperson myself - after all*, I'm a project manager, not an evolutionary biologist. And, as a layperson, I likely often make mistakes when talking or writing about Darwinian evolution. So I'm not making the case that everyone always has to get everything right. But I do think that it's somewhat important to avoid certain specific phrasings that provide fodder for critics and motivated skeptics. Sure, the process of evolution can, and inevitably will, given enough time, alter an entire species to a point where, if you could re-create an archaic example of that same species, interbreeding with the modern population would no longer be possible. (This process is termed "anagenesis.") This isn't say that the particular word choice should never be used - only that it's worth being careful with, so as not to engender confusion or needless controversy.

People taking the statements of the uninitiated as gospel, however, is something that I encounter all the time. Especially when those statements can be construed to fit in with preconceptions about the topic at hand.

* (Feel free to insert "Damnit, Jim!" here.)