Primordial Soup, the game
Primordial Soup looks like a fun simulation game, especially for giving kids an introduction to the basic principles of evolution (PDF) and how to coƶperate and think critically (DOC).

You can read a review of Primordial Soup over at RPG.net and another review at GamerDad.
It’s times like this when I wish I had kids, although I’ve never had to use that as an excuse to indulge my penchant for board games before.