What are the ethics of creating new life in a simulated universe?

When Anders Sandberg was a kid in the 1980s, he enjoyed making simulations on his Sinclair ZX81, mocking up mini solar systems. Later, he graduated to designing artificial neural networks that use learning algorithms inspired by the brain. "Some people relax by watching television. I program simulations while listening to philosophy lectures," Sandberg chuckles. One day back in 1999, he recalls, he deleted a copy of a neural network on his computer and got a "tinge of bad conscience." He couldn't help worrying: "Have I just killed a little creation?"