I absolutely agree that what the author refers to as "Darwinism" is testable.
Let's see the data that supports random variation of complex multicellular organisms leading to speciation.
Bring it on.
The variation is not random - as one might say about a flash-in-the-pan 'accidental' happenstance - but rather a self-organizing process driven by natural selection.
To use an analogue that's been common around here lately, evolution is no more "random" than is the food supply network of New York City.
We're here to help: 29+ Evidences for Macroevolution. When you've digested that, let me know. We have more. Lots more.
All you have to do is compare the genomes of known species. You see the evidence for random variation, and of selection. It's all there.