A big step in understanding the mysteries of the human genome was unveiled today in the form of three analyses that provide the most detailed comparison yet of how the genomes of the fruit fly, roundworm, and human function.

About 400 million years ago a group of fish began exploring land and evolved into tetrapods – today's amphibians, reptiles, birds, and mammals. But just how these ancient fish used their fishy bodies and fins in a terrestrial environment and what evolutionary processes were at play remain scientific mysteries.