Endosymbiosis

2014, Robert E. Blankenship, Molecular Mechanisms of Photosynthesis, Wiley Blackwell, 2nd Edition, page 226, Evidence is now overwhelming that several groups of eukaryotic algae originated from a secondary endosymbiosis, in which a eukaryotic alga was incorporated into a second host (Palmer and Delwiche, 1996; Delwiche and Palmer, 1997; Delwiche, 1999; Keeling, 2010, 2013; Curtis et al., 2012).

Interspecific associations are currently believed to take part in evolution by improving a partner's fitness through integrated endosymbioses or by causing reproductive isolation and subsequent host speciation, such as in the Wolbachia endosymbioses (Nardon and Grenier, 1991; Margulis, 1993a; Bordenstein et al., 2001).

The second chapter (by David Smith) describes the primary endosymbiosis as an introduction for secondary endosymbioses. He illustrates the origin of primary endosymbiosis, plastid genome evolution, and loss of photosynthesis in some lineages of Archaeplastida.