Wednesday, September 10, 2008

Evolution Video Games

The video game Spore just came out. It was in development for years, the brain-child of Will Wright, the guy who did all the Sims games. Supposedly Wright got input from scientists while making the game, but the game is getting mixed reviews from scientists. Some are saying that it actually spreads misinformation about evolutionary processes.

Some of the criticism I've heard is that there's too much tinkering on the part of the user to have the dynamics qualify as anything resembling evolution. Another is that the game has pre-ordained directionality: There are five stages to the game, and they always occur (cell, creature, tribal, civilization, space). Evolution doesn't work this way.

If you want to try a free video game that's a little truer to evolutionary dynamics, here's NERO, Neuro-Evolving Robotic Operatives, developed at the University of Texas at Austin. It's a combat game in which you tune the selection pressure of evolving populations of robotic soldiers in order to develop armies with particular characteristics. For example, in training mode (pictured here), your robots spawn by falling out of the sky and landing in the arena.

You can place obstacles, such as walls, or enemies, such as machine gun turrets, anywhere in the arena. When soldiers die from being shot by enemies, new ones spawn, and the controllers of the offspring are mutated descendants of the other members of the population. You can control the behaviors selected for by adjusting scroll bars. For example, you can control whether your soldiers evolve to be "kamikazes" or "evaders" by adjusting the pressure for them to either run straight at, or avoid gun fire. Once you've trained an army, you cut them loose in a battle situation and see how they fare.

Their morphologies don't evolve, just their controllers, or "brains". And this is really more a case of artificial selection than natural selection. Natural selection is pressure from either external environmental conditions or interaction with other non-human organisms that causes differential survival in a populations. For example, if the environment cools in a particular region over multiple generations of a species that has fur, like a fox, those individuals with thicker fur might be more likely to survive and reproduce, and thus more offspring in the population will have thicker fur.

Artificial selection is when the selection pressure is determined by humans. For example, a farmer is able to sell plumper, sweeter corn at market, so each time he harvests and plants, he picks kernels from the plumpest, sweetest plants to start the next crop. After successive generations, corn in this population has much larger, sweeter kernels than it did several generations ago.

Video games are going to necessarily involve artificial selection. Otherwise, the player would have nothing to do. Evolution by natural selection is an inherently undirected process, and wouldn't much make for fun game play.

I've done some work with evolutionary algorithms, and I enjoy sitting back and watching a population evolve. But I don't think this has much wide appeal. And even though NERO is a cool concept, when I played it, I didn't really think it was all that fun.

Creatures is another game series that was developed in the 90's, but I never played it. There's something appealing about the idea of playing god, determining who lives and dies in an evolving ecosystem based on your decisions, but the interaction is indirect, and its the evolving organisms that are doing most of the work.

So as much as I think the idea is cool, I don't think video games really based on evolutionary processes are going to take the gaming world by storm. However, I think if they are faithful to the science, mini-games based on evolution could be invaluable teaching tools at just about any level in education.


Kenny Wyland said...

Uh... dude. Go to and watch the intro movie. It says over and over that "someone decided" to change the creature and that "someone is you."

It doesn't say these creatures evolve... it says you create and change them. You are their creator. You've kind of missed the mark here.

Derek James said...

Why does the game follow the trajectory from cell to organism to civilization if it's not trying to mirror evolution in some way?

Here's an excerpt from a NY Times article with an interview of Will Wright:

The game, which he eventually renamed Spore, would give players an experience of life and the universe across billions of years, from microscopic creatures to interstellar civilizations. “There were deep motivations in the early phase from the work of a lot of evolutionary biologists, like Richard Dawkins and Edward Wilson,” Mr. Wright said in a telephone interview.

Mr. Wright wanted Spore to communicate some of the grand patterns of evolution. But he did not want players to spend a million years waiting for something interesting to happen. He also did not want the game to look like an abstract cloud of drifting spots.

“I spent a fair amount of time going around to talk to scientists here and there,” Mr. Wright said. “You have to explore a huge amount to figure what 20 percent will be cool and fun for a game.”

One thing Mr. Wright and his colleagues decided Spore should reflect was evolution’s ability to produce life’s staggering diversity. “We wanted to convey the sense that evolution can bring up a surprising diversity of weird, interesting, strange things,” he said.

Why is the creator of the game even referencing evolution if the game has nothing to do with it?

Kenny Wyland said...

Well, by his own words “You have to explore a huge amount to figure what 20 percent will be cool and fun for a game.” I'm not saying there aren't any elements of evolution in the game, but the primary focus of it is that you are their creator and you get to decide how they change. He said there was 20% of the evolution stuff he researched that could be cool and fun for the game, which leaves 80% non-evolution. It's pretty clear to me that the game as a survival-of-the-fittest theme, but you as their creator decide how to change them. I think you're focusing on the one word and making or breaking the whole game on that one word.... but that one word is such a small part of the game.