Was the Slave Initially Photosynthetic

The more secure new rooting of the eukaryotic tree (Fig. 8.1) is between bikonts, which almost certainly ancestrally had tubular mitochondrial cristae, and unikonts, which comprise the Amoebozoa with tubular cristae and opisthokonts with flat cristae (Richards and Cavalier-Smith 2005 Stechmann and Cavalier Smith 2003). The cenancestral eukaryote probably therefore had tubular mitochondrial cristae. The majority of photosynthetic a-proteobacteria have tubular chromatophores, which carry the dual 

It is most likely that the protoeukaryote host and enslaved purple symbiont were both facultative aerobes, able to live under anaerobic or aerobic conditions (Cavalier-Smith 2002b) this makes their coming together easy to understand and fits all we know of the diversity of mitochondrial/hydrogeno-somal properties as well as of the rest of the eukaryotic cell, especially in the basal kingdom Protozoa. Given that most actinobacteria are aerobes, it is 

The driving force of the second phase was probably completely different -correction of harmful phenotypic costs inevitably stemming from the success of the first phase once the a-proteobacterium had become a permanent 

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