The evolutionary origins of hydrogenosomes have been the subject of considerable debate. This volume closes the gap between the endosymbiotic theory for the origin of organelles and their incorporation into evolutionary theory. It reveals that identifying the genetic contribution to eukaryotes of the mitochondrial endosymbiosis, and revealing the functions of its descendent organelles, are key to understanding eukaryotic biology and evolution.

The Road to Hydrogenosomes.- Mitochondria: Key to Complexity.- Origin, Function, and Transmission of Mitochondria.- Mitochondria and Their Host: Morphology to Molecular Phylogeny.- Anaerobic Mitochondria: Properties and Origins.- IronSulfur Proteins and IronSulfur Cluster Assembly in Organisms with Hydrogenosomes and Mitosomes.- Hydrogenosomes (and Related Organelles, Either) Are Not the Same.- The Chimaeric Origin of Mitochondria: Photosynthetic Cell Enslavement, Gene-Transfer Pressure, and Compartmentation Efficiency.- Constantin Merezhkowsky and the Endokaryotic Hypothesis.- The Diversity of Mitochondrion-Related Organelles Amongst Eukaryotic Microbes.- Mitosomes of Parasitic Protozoa: Biology and Evolutionary Significance.