title: Of early animals, anaerobic mitochondria, and a modern sponge.
abstract: The origin and early evolution of animals marks an important event in life's history. This event is historically associated with an important variable in Earth history - oxygen. One view has it that an increase in oceanic oxygen levels at the end of the Neoproterozoic Era (roughly 600 million years ago) allowed animals to become large and leave fossils. How important was oxygen for the process of early animal evolution? New data show that some modern sponges can survive for several weeks at low oxygen levels. Many groups of animals have mechanisms to cope with low oxygen or anoxia, and very often, mitochondria - organelles usually associated with oxygen - are involved in anaerobic energy metabolism in animals. It is a good time to refresh our memory about the anaerobic capacities of mitochondria in modern animals and how that might relate to the ecology of early metazoans.
authors.affiliation: Faculty of Natural Sciences, Department of Biochemistry, Comenius University, Bratislava, Slovakia.
authors.forename: Marek
authors.initials: M
authors.lastname: Mentel
authors.forename: Mayo
authors.initials: M
authors.lastname: Röttger
authors.forename: Sally
authors.initials: S
authors.lastname: Leys
authors.forename: Aloysius G M
authors.initials: AG
authors.lastname: Tielens
authors.forename: William F
authors.initials: WF
authors.lastname: Martin
mesh_terms: D000693:Anaerobiosis / Q000235:genetics; D000818:Animals; D004734:Energy Metabolism / Q000235:genetics; D053858:Metabolic Networks and Pathways; D008928:Mitochondria / Q000235:genetics / Q000378:metabolism*; D010802:Phylogeny; D011161:Porifera / Q000378:metabolism*
keywords: Neoproterozoic ocean chemistry; anaerobiosis; eukaryotes; geochemistry; hypoxia; mitochondria; rhodoquinone