Civilization IV: meaning of "Babylonian merchants are now selling domesticated prairie dogs as exotic pets"?

I just started a game of Civilization IV (Beyond the Sword) and the following message appeared in the Event Log:

2960 BC: Babylonian merchants are now selling domesticated prairie dogs as exotic pets.

Is this just a joke or does it actually have some relevancy to the game? :s (I'm playing as Tokugawa, the Babylonians are one of my neighboring civilizations).

Solution 1:

This is one of several random events that were added in the Civ IV expansion -- the prairie dog event in particular means that one of the Babylonian tiles has, randomly, received +1 Commerce.

Solution 2:

Seems to me like it's a nod to an old 'strategy' game, M.U.L.E. maybe...

There were events in that game that were all pretty goofy things happening between rounds.