Symbiogenesis is the merging of two separate organisms to form a single new organism. The idea originated with Konstantin Mereschkowsky in his 1926 book Symbiogenesis and the Origin of Species, which proposed that chloroplasts originate from cyanobacteria captured by a protozoan. Today both chloroplasts and mitochondria are believed to have such an origin; this is the endosymbiotic theory. Theory of symbiotic relationships driving evolution In Acquiring Genomes: A Theory of the Origins of Specie… (More on Symbiogenesis)