The objects on EndlessForms.com are evolved in the same way that plants and animals are bred. You pick the ones you like and they become the parents of the next generation of objects. As in biological evolution, the offspring look similar, but not identical, to their parents, allowing you to explore different designs. Under the hood, there is a genome for each object. To create offspring the parent genomes are randomly mutated. If two parents are selected, some of the offspring result from "crossing over" (combining portions of) the genomes of the parents, as happens in biological sexual reproduction.

The idea of interactively evolving designs dates back to Richard Dawkins Biomorphs. What makes the technology on this site special is that it is based on principles from biological development. Development is the process by which a single cell turns into a complex organism, such as a jaguar, hawk, or human. A major challenge for biology is that each cell in a natural organism has to determine what type of cell to become, even though every cell has the same genetic code. Nature's solution is to have the type of cell be determined (in part) by its geometric location. To anthropomorphize, a cell first asks "Where am I?", and the answer to that question helps it determine whether to become a heart cell, a skin cell, a brain cell, etc. Since cells cannot ask a global positioning system for their exact geometric coordinates, developing organisms create chemical gradients (e.g. 'head to toe') that provide such positional information. The genes in a developing organism are then turned on and off based on these geometric gradients, and those genes produce new geometric information that will trigger other genes, and so on. One gene may only be active in the front (anterior) of an organism, for example, which can help genes in that region produce head cells instead of tail cells. At an abstract level, that is a main driver of how cells differentiate.

An abstraction of this developmental process produces each object you see on EndlessForms.com. For each voxel (a small cube) in the allowable area, information about its geometric coordinates (e.g. its X, Y, and Z coordinates) are input into an evolved genome. The genes in the genome turn on and off in response to that information, creating new geometric patterns that affect other genes, etc. Eventually the output of the network is a single value, which specifies whether material should fill a voxel or not. The genome thus specifies where material exists based on geometric information, just as in natural organisms. A difference between our site and nature is that geometric information is represented mathematically, which is more computationally efficient than simulating the diffusing chemicals in natural organisms.

There are other factors in development besides geometric information, but they do not play a role in this website. What is interesting, which this website helps explore, is how complex objects can be when genes utilize only such geometric information.

This website was inspired by a similar experiment with the same technology that evolves two-dimensional images at Picbreeder.org. We thank them for pioneering these ideas and recommend you check out their amazing site.

Additional reading:

• Clune J, Lipson H (2011) Evolving three-dimensional objects with a generative encoding inspired by developmental biology. Proceedings of the European Conference on Artificial Life. Pages 141-148. (pdf)
• Clune J, Stanley KO, Pennock RT, Ofria C (2011) On the performance of indirect encoding across the continuum of regularity. IEEE Transactions on Evolutionary Computation. 15(3): 346-367. (pdf)
• Stanley KO (2007) Compositional pattern producing networks: A novel abstraction of development. Genetic Programming and Evolvable Machines. 8(2): 131-162. (pdf)
• Carroll S (2005) Endless forms most beautiful: the new science of evo devo and the making of the animal kingdom.