In 2258, IPX sponsored a dig on Ikarra VII lead by Dr. Vance Hendricks. During which they found a number of artifacts in a vault buried nearly a mile
beneath the surface. Up until that point it wasn't known that Ikarra was home to a space-faring culture. The artifacts turned out to be Organic Technology originating from around the time of the First Shadow War and were used as weapons to repel an invasion - of which there had been over a half dozen within the previous centuries, each from a different alien race and each more deadly than the previous. Though the weapons were successful, their parameters for defining the "pure Ikarran" were set by a coalition of religious fanatics and military extremists to be an unrealistic, idealised standard that no Ikarran conformed to, or could conform to. By these standards the entire Ikarran species was "impure". The weapons therefore turned on the Ikarran people, killing every Ikarran, wiping out the civilisation and exterminating the race.
The timing of the Ikarran extinction combined with a planet fighting against repeated invasions and their use of organic technology may indicate that they had some involvement with, or possibly assistance from the Shadows.