Featured in the 2001 comedy film Evolution; these lifeforms are based on nitrogen, rather than carbon; and have a much faster metabolism than Earth creatures; as they are able to evolve into new species in a matter of hours or days, rather than millennia. They also have ten different fundamental bases in their DNA; whilst Earth organisms have only four. Exposure to great temperatures like explosions or fire causes these aliens to increase size tremendously. In the television series, the aliens are referred to as "The Genus". The tv version does too have an intelligent form, called SCOPES.