ArsTechnica has a very interesting video that features Richard Garriot, co-creator of Ultima Online, discussing the virtual ecology of the game and how it went pear shaped as soon as the game was released.
When creating Ultima Online, Richard Garriott had grand dreams. He and Starr Long planned on implementing a virtual ecology into their massively multiplayer online role-playing game. It was an ambitious system, one that would have cows that graze and predators that eat herbivores. However, once the game went live a small problem had arisen...
Source: http://video.arstechnica.com/watch/war-stories-ultima-online-the-virtual-ecology [arstechnica.com]