Is it possible to evolve radio communication through Darwinian evolution?

Could a creature ever conceivably evolve all the components of a radio transmitter and receiver, including tuners and resonators etcetera?

My next species, the Shaan, are an experiment to see just how strange animal communication could be if the environment favored them. They are either going to transmit information using electric fields in the manner of some catfish and knifefish (which seldom works out of water; air does not conduct very well), or they are going to be walking radio stations. But first I need to discover if it would be impossible to evolve a radio naturally.

I am not a scientist. And so I call on any who are to offer their opinions on the matter of radio communication. I just don't know enough at this time. Electro communication is however far more straight forward because it has happened on earth before.

Creatures that exploit electricity to survive and chat to one another include electric eels (a knifefish), electric catfish, sharks (which passively detect electric fields using highly conductive pits in their nose and face) and even the platypus which uses its bill to detect the electricity generated by the contracting muscles of its prey.

The one thing these animals have in common is that they hunt in water. Air is probably not conductive enough to warrant electrolocation, where eyes and ears provide sufficient sensory input.

So here is my first draft of an environment that could make land creatures favor electric sensory systems:

The homeworld of the Shaan orbits a star brighter than our own, with high levels of light and heat. Average temperature at sea level is 46 degrees C, with little temperature variation across the surface. This is because the atmosphere is loaded with water vapor, trapping heat and distributing it across the worlds' surface. In this permanent hot soaking fog, visiblity is less than on earth. Sunlight does not reach the surface as powerfully as our planet and so the vegetation is very dark to absorb more light, from deep reds and purples to almost black. Basking in the heat and moisture, plant life has run riot and verdant sweltering jungles cover most of the land in darkness. The air is dense, with air pressure higher than earth and soaked with oxygen from the photosynthesizing plants.

In this environment, one branch of life similar in some ways to earth vertebrates uses the soupy, moist air as a conductive medium for electric navigation, prey detection and eventually communication.

The Shaan are well adapted: Their bodies are long and snake-like, easily moving through thick undergrowth. Their tough leathery skin evolved to resist infection by the fungus like lifeforms that infest the forests. Six legs carry claws to hunt and climb, but can be folded against the body to swim and slither through rivers and rotting leaves. Its thick short tail is filled with fat tissue to store energy.

Its head carries a huge beak, taking up a quarter of the body length. This contains sensors and organs to produce and receive electric signals. Folded inside the beak are scythe like mandibles which tear huge chunks of meat from unfortunate animals.

When they hunt they also communicate electrically, sending pulses of information to each other. This allows them to co-ordinate hunts accurately because of the large information content of their language. This language allowed them to evolve complex caste societies, with queens nesting along riverbanks with 10 or so of their young who bring her food and keep her clean.

Both Shaan queens and drones are highly intelligent. In their future they will posses a technological society of vast power. But that is a story for later.