I know you weren't going there, but I sometimes enjoy speculating about the possibility of tool-using, even radio-building (or spacefaring!) lifeforms who are not, by our standards, intelligent. The "technologies" of bees and wasps give all the appearance of deliberate design. What is the practical limit of the complexity of such instinctive constructions, in the absence of abstract creativity?
What an interesting speculation! I have never truly pondered it in quite this way.
Why should there be a limit at all, beyond the obvious limits of the laws of physics? Your DNA is a fiendishly complex molecule, but at the end of the day, it's still just a molecule, lacking any sense of "abstract creativity" whatsoever. And yet it produced you, a fiendishly complex construction yourself...
As for naturally occurring radio communication...all green plants convert light into chemical energy, and we also have insects that communicate simple messages to each other by doing the opposite, and converting their chemical energy into light impulses. Which makes me wonder if there are potential biochemical processes whereby a different sort of energy - energy in the RF band, for example ;) - can be converted to and from chemical energy useable by biological organisms. Instead of chemiluminescence, imagine an organism that incorporated small amounts of a natural semiconductor like galena or iron pyrite or silicon, in order to, say, form a simple diode...
If "abstract creativity" came into being by layering more sophisticated tropisms on top of less sophisticated trophisms, in wired up neural networks, whose to say ants or termites can't do the the same thing, "wired" up in the chemical communication networks they direct each other with? If it gets the job done--does it matter that it's not a neurally-operated meat machine?
Question is--will it ever invent a knock-knock joke?