Random can mean "arbitrary." It can also mean "unpredictable."

Evolution at the species level is unpredictable and so "random" in that sense. No one can *accurately* predict, for example, when or even if human beings will evolve into another species; or, if they do, what that species would be like. Contrast that with chemical reactions, which are routinely predictable.

But being unpredictable isn't the same as being arbitrary or causeless. True causelessness is disorder and chaos. (That does make it unpredictable, but despite the overlap the two concepts are distinct.)

Evolution is orderly (not "random") in so far as it exhibits both cause and effect. (In that way it's like everything else above the quantum level.) Unpredictable evolutionary changes don't violate ordinary cause and effect. The class of dinosaurs that evolved into birds did not suddenly and for no good reason lose their teeth, sprout wings, and fly. The slow change resulted from unpredictable but orderly interactions between genetics and environment.

Scientific discussions of evolution reasonably take it for granted that people will not interpret "random" to mean "causeless" - which is what I took Pete to mean.

Since I'm not a professional philosopher or an evolutionary biologist, perhaps I'm quite mistaken about all of this. Readers of this thread will decide for themselves the meaning of "random" in various contexts.