The theory of the Aiju stems from an anomalous similarity in the DNA of the sentient species of the . Despite their origins being on different worlds, some of the region's races appear to be partially related genetically. The Homar and Estari races are perhaps most striking, with some sources quoting a staggering 82% similarity of genetic code. The Aiju Theory is the postulate that an ancient species existed, that somehow mingled with the Kasperion races during their pre-civilised development. This would appear to explain the appearance of common DNA structures across interplanetary distances.