Genus (Evolution)

The Genus is a biological organism known for its ability to evolve into new forms quickly, forming elaborate ecosystems and generating new species in a matter of hours or days.

Biology
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 high temperatures, such as explosions or fire causes these aliens to increase in size tremendously.

Their origin is unknown. They arrived on Earth as blue-colored unicellular lifeforms inside a meteorite and soon started to evolve into multicellular forms, eventually spawning an entire ecosystem within the meteor's crater, which included species analogous to lichens, worms and insects.

All Genus lifeforms reproduce asexually, which is interesting given that this form of reproduction is often believed to be associated with slow, rather than fast, evolution. After a few days, some vertebrate analogues escape and start giving rise to several reptilianoid, and later mammalianoid forms, which threaten to take over Earth's entire ecosystem in no more than a few months. The only thing slowing down their progress is that they cannot breathe oxygen properly, making them slow and short-lived. Eventually however, some of the aliens do evolve the ability to breathe oxygen and become far more dangerous. Based on the projections by Dr. Reed's team, it is estimated that the alien ecosystem will overwhelm the United States in two months.

In an attempt to wipe out the aliens, the USA military decides to carpet-bomb the meteor site with napalm, supposedly destroying the center of alien activity. They were unaware of the creatures' biological response to such explosions, however, and instead of killing the aliens, the explosion results in the smaller lifeforms growing uncontrollably and fusing together to form a gigantic, amoeboid meta-organism. Finally, a weakness of the aliens' biology is discovered: selenium, which is in the same position relative to nitrogen as arsenic is to carbon. Using large quantities of selenium, the giant alien is poisoned and killed.

Appearances

 * Evolution (2001)
 * ''Alienators: Evolution Continues" (2001-2002)