<P> After arriving in the Pegasus Galaxy, the Ancients settled on a planet they named' Lantea', calling themselves' Lanteans' from that time forward (also, they have been referred to as' Atlanteans' by members of the Atlantis Expedition - a name often used by the peoples of Pegasus to describe the expedition members). Finding Pegasus devoid of sentient life, the Ancients dispersed humans and Stargates across their new home galaxy, protecting the newly populated planets and occasionally inhabiting them (usually concealing their true identities as Ancients). The humans seeded by the Ancients came to know them as' the Ancestors' . At some point they encountered a leech - like organism called the' Iratus bug', which possessed impressive healing and immunological capabilities . Through feeding on humans (and processes of evolution), this organism absorbed genetic information from humans and eventually evolved into the vampire - like Wraith . Although it remains unknown precisely how this evolution occurred, the Ancients have confirmed that they were responsible for the species' emergence . </P> <P> The Wraith, over a vast period, developed into an advanced but violent society (with vestiges of territorialism that were later harshly revived when their prey became scarce) - all the while avoiding the attention of the Ancients . When the sentient Wraith were discovered by the Ancients, it appears their ferocity, belligerence and large population were underestimated . The Ancients sent a delegation protected by their most powerful warships to negotiate with the Wraith, but the ships were ambushed and destroyed . The Ancients and Wraith went to war, and despite the Ancients' technological superiority, the Wraith overwhelmed the Ancients with their sheer numbers . During their war which lasted for centuries, the Wraith eventually conquered every planet in the Pegasus Galaxy until only Atlantis, the capital of their empire, remained protected by its powerful city shield . </P> <P> The Ancients were able to hold the Wraith back with their superior weapons for a hundred years, until they were forced to submerge the city and to leave the Galaxy, for no matter how long they stalled the destruction of Atlantis, the Lanteans were unable to overcome the endless number of Wraith . They started to make more desperate experiments, such as Project Arcturus, a failed attempt to draw Zero Point Energy from their own universe, instead of from within an artificially created region of subspace as in Zero Point Modules . However, containing zero point energy in our own space - time caused serious containment issues, killing the Ancients and the people of Doranda, the planet it was based on . They also developed nanites designed to fight the Wraith on a cellular level, giving them aggression codes surpassing that of the Wraith . The nanites took human form, becoming a race known as the Asurans . They begged to have the aggressive nature removed from their programming, but the Ancients refused . Once it became clear the Asurans would never be the weapon the Ancients hoped for, they were subsequently exterminated by the Ancients . Not wanting anyone to find out their mistakes, the Ancients deleted all references to the Asurans in the Atlantis database, save for the gate address . A few of the nanites survived and brought up a second evolution, re-creating Asuran society . It is believed that at one point in time the Asurans even created several nano - viruses specifically designed to kill humans, so as to deprive the Wraith of a food supply . One such virus, which causes hallucinations and death caused by a brain aneurysm, was encountered in a lab on Atlantis . Janus, an Ancient scientist, also built a device called the Attero device, which emitted a specific frequency of subspace distortion, causing Wraith ships to explode when attempting to enter hyper - space . It was later shut off and ordered to be destroyed (an order Janus, as usual of him, disregarded), because the same frequency which damaged the Wraith ships also caused an explosive overload in active Stargates . </P> <P> The Ancients also pursued technological means of accelerating the process of Ascension through a variety of mediums . Before the war reached its final stages, they selected a hospitable planet and enclosed a portion of its surface inside a time - dilation field . Within the field, time passed much more quickly than outside, allowing the humans within to spend many generations undisturbed in seclusion and meditation in order to reach ascension, whilst remaining undisturbed by the Wraith . On Atlantis, they built a DNA Resequencer designed to modify DNA, fulfilling the physiological component of ascension . This had varying results . </P>

Who made the nano virus in stargate atlantis