Hey, it has been a while since I posted here, but this got my attention. I've been pondering this kind of application for years now and what you propose sounds cool and doable but involves a lot of programming.

The URL below links to the site of the dissertation my wife and I did a few years ago on Artificial Life. Part of the dissertation was an application that lets loose agents on a created world. The world is filled with resources, the agents follow certain rules and are react differently based on genes and a RPG-like development of their skills.

http://www.softline.be/StrategicAlliance/ALife/en/index.htm
(check it out, tell me what you think of it)

There is the possibility to alter the environment with pollution which reduces resource output and thus adversely affects the agents. The agents are not programmed to survive per se, they are programmed to act in the world and they are given the means to survive, trade, procreate,...

The application 'proves' certain Darwinistic tendencies and seems to simulate realistic economic and ecological behaviour. In some ways it is far more complex than Sugarscape which was written years ago and still seems to be one of the field standards. But it is far from the 'history creating' application you describe. The reason why that kind of application does not exist yet is because of the inherent complexity of it. You can go two ways in that kind of application :
A) 'scripted' : You script every major development and hardcode the invention of farming, city building,... into the game. That way you are sure that the creatures will eventually get to these events. The simulator is then just a randomly generating history machine in which only the time and culture that invents the scripted events is different each time you run it.
B) real artificial life : You don't script any major advance in the history of mankind. Instead you give your creatures general needs and abilities that allow them to act in the world based on rules that you make as free as you can. In that case however you'll not have the history application you describe but an aquarium of creatures that may or may not react like you think they would. They may never invent something that remotely looks like farming because in their world it is not viable. They may wander off and not live in cities. In my opinion, that is the real way to go, as open-ended as possible. But it is also the most troublesome just because you have nothing scripted. You may observe your creatures farming the world but since you did not describe farming in the code you can not note it in the log.

Of course there are ways to compensate for this, but it'll take you a lot of time. However if these things interest you it is time well spent because as far as I know, in all these years no person, no university team has ever created a mindblowing open-ended artificial life generator that tries to model the development of mankind.

Phew, long post, just my 2 cents,...
Greetz,