SYSTEMATIC BIOLOGY

THE AMOEBOZAE
BIKONT-UNIKONT EVOLUTION AFTER CAVALIER-SMITH & CHAO (2003)
Cavalier-Smith and Chao (2003) present a scenario in which the unikonts, those organisms with single flagella, are paraphyletic.  They root the eukaryotes in a line from a group of Gram positive eubacteria, which gave rise to the eukaryotes and the archaea.  The stages in the origin of the eukaryote line were the organization of microtubules to form a flagellum (not the endosymbiotic origin as Margulis claims) and the later acquisition of a mitochondrial endosymbiont.  The single flagellar structure gave rise to the Opisthokonts (taxa with a single trailing or pushing flagellum and flat mitochondrial cristae) and the Anterokonts (taxa with a single anterior or pulling flagellum and tubular mitochondrial cristae).  The anterokonts (e.g. Amoebozoae) gave rise to the Bikont line, which they presumed to have arisen through an apusozoan-like organism.  See Cavalier-Smith (2003) for an elaboration on this scenario.

This page is maintained by Jack R. Holt. Last revised: 03/06/2007.