for symbiotic inclusions is clear from the fact that all Eukaryotes, except for a few primitive anaerobic varieties, such as the metamonad human gut parasite Giardia lamblia, all have endosymbiotic respiring mitochondria, which are evolutionarily related to α-proteobacteria such as Rickettsiae (Emelyanov 2003 ). Plants also have photosynthetic chloroplasts derived from