When Will Wright was developing Spore, his much acclaimed computer game, he interviewed several life scientists. He asked them how nature had actually done what he was attempting to simulate in the game—which was, among other things, the development of the earliest stages of life and its evolution. (Some billboard advertisements for the game feature the slogan “Evolution Begins at Spore.com.”) Among the scientists Wright consulted were Michael Levine, a geneticist at the University of California, Berkeley; Neil H. Shubin, a paleontologist at the University of Chicago; and Hansell Stedman, a surgeon at the University of Pennsylvania School of Medicine.

But for all the research that went into it, Spore comes off as a mixed success at replicating the inner workings of evolution by natural selection. On the plus side, in both the game and the real world, there is competition among individuals: Darwin’s well-known “struggle for existence.” In both, the more fit survive, and the less so die out, duplicating the basic evolutionary principle of survival of the fittest. In the game and in real life, simple entities develop into more complex ones, a pattern that is a common, though not an inevitable, feature of Darwinian evolution. Finally, in both Spore and in nature, life-forms tend to be bilaterally symmetrical, even though exceptions occur in real-life creatures such as amoebas as well as in some of Spore’s unicellular organisms.

Spore encompasses five stages of development: cell, creature, tribe, civilization and space. There are some potent differences, however, between evolution as it actually operates and Spore’s animated version of events. For one, in the “cell” and “creature” stages of the game, organisms win “DNA points” when they achieve certain goals. Evolving to a higher level of existence is a matter of acquiring DNA points, much as travelers might accrue frequent-flier miles in an effort to go places. In the real world, in contrast, organisms evolve through random genetic mutations, by sexual reproduction and by other mechanisms but not merely by amassing DNA.

Second, at many defining moments in the game the player is given a narrow range of alternatives and is forced to choose among them from a predefined menu of possibilities. In the cell stage, for example, you have to choose whether to develop into a carnivore or a herbivore. In the real world, the range of possibilities at any fork in the evolutionary road is vastly greater, richer and more undefined.

Generally, evolution proceeds slowly in small steps. Although theorists debate over the precise rates of evolutionary change, Spore moves along at comparative light speed, in many cases by huge leaps, as entire body parts—hands, feet, jaws, eyes, limbs—are grafted onto an organism and smoothly integrated into its functioning. These miracles are performed by a “creature editor,” an application that allows the user to choose from a palette of prefabricated, preassembled body parts, each of which can be attached to the organism with a few swift clicks of the mouse. The various items in these parts bins have, of course, not themselves evolved but have been designed and stockpiled by the game’s creators.

Evolution is a branching process with multiple lines of descent operating simultaneously and in parallel. When played solo, Spore is essentially linear and one-dimensional, with the player controlling the activities of a single cell or creature. (At the “tribe” stage, the player controls the behavior of several tribal members, but these specimens are now biologically fixed and no longer undergo changes to their size and shape.) When the game is played online, however, the player interacts with other Spore players and can download their creations from a “Sporepedia,” a large collection of living things (as well as of inanimate objects such as buildings, vehicles and even music). With this feature, Spore approaches a level of parallelism that is actually found in nature.

Which brings us to the greatest difference between Spore and evolution by natural selection, namely, that whereas evolution is an emergent phenomenon with no conscious “selector,” Spore quite obviously has one: the user. It is the user who selects for or against things at every juncture: body parts, traits, behaviors, colors, textures, patterns, shapes. Spore does not in fact proceed by natural selection at all but rather by artificial selection. Indeed, putting the player in the position of an omnipotent creator makes the game more a simulation of intelligent design than of real-world Darwinian selection.

Spore may well be the ultimate computer game, the high-water mark of computer animation. You may find it mesmerizing or boring, sophisticated or silly, more Disney than Darwin.

Nevertheless, it is an amusement that holds a special appeal for some. Planetary scientist Frank Drake, author of the Drake equation, a formula for estimating the likely number of extraterrestrial civilizations in the our galaxy, says: “I think it is a good game for kids. It will plant the idea in their heads that the creatures of Earth (and elsewhere) have not always been the same, that species have come and gone and that, in general, the complexity of living things has increased over time. This in turn should encourage many of them to study science, and that, in the end, could be the greatest benefit of the game.”

Note: This article was originally printed with the title, "The Science of Spore".