Summary: Current Biology 19, R81­R88, January 27, 2009 ª2009 Elsevier Ltd All rights reserved DOI 10.1016/j.cub.2008.11.067
ReviewThe Puzzle of Plastid Evolution
John M. Archibald
A comprehensive understanding of the origin and spread
of plastids remains an important yet elusive goal in the
field of eukaryotic evolution. Combined with the discovery
of new photosynthetic and non-photosynthetic protist
lineages, the results of recent taxonomically broad phylo-
genomic studies suggest that a re-shuffling of higher-level
eukaryote systematics is in order. Consequently, new
models of plastid evolution involving ancient secondary
and tertiary endosymbioses are needed to explain the full
spectrum of photosynthetic eukaryotes.
Introduction
Our planet is teeming with photosynthetic life. The textbook
version of how this came to be is relatively straightforward:
oxygenic photosynthesis first evolved in the ancestors of
modern cyanobacteria more than two billion years ago [1]
and their light-harvesting capabilities were subsequently
exploited by eukaryotic (nucleus-containing) cells through

Source: Archibald, John - Department of Biochemistry and Molecular Biology, Dalhousie University

Collections: Biology and Medicine