Deep-sea hydrothermal systems

The discovery of the deep sea hydrothermal systems, and the sulphur-metabolising bacteria which live in them, caused some researchers to look more closely at the element sulphur. It seemed obvious to consider a link between sulphur bacteria— primitive life forms—and the emergence of the simplest forms of life, de Duve, 1974 Nobel Prize winner for medicine, joined the ranks of the biogenesis researchers in the 1980s. 

The energetics depicted in this way are in accord with the microbial ecology observed at deep sea hydrothermal systems (e.g., Kelley el al., 2002 Huber el al., 2003 Schrenk et al, 2003). Sediments and black smoker walls invaded by hydrothermal fluids there contain sparse microbial populations of mostly thermophilic methanogens and sulfate reducers. Abundant populations of mesophilic aerobes dominated by sulfide reducers, in contrast, are found in the open ocean where hydrothermal fluids mix freely with seawater. 

Takano, Y., Marumo, K., Ebashi, T., Gupta, L.P., Kawahata, H., Kobayashi, K., Yamagishi, A., and Kuwubara, T. 2005. In situ ore formation experiment Amino acids and amino sugars trapped in artificial chimneys on deep-sea hydrothermal systems at Suiyo Seamount, Izu-Bonin Arc, Pacific Ocean. Bull. Chem. Soc. Jpn. 78 638-651. 

The RNA world is one of several hypotheses for the origins of life. Another hypothesis proposes that life originated near deep-sea hydrothermal systems... 

Takano, Y Kobayashi, K. Yamanaka, T. Marumo, K. Urabe, T. Amino adds in the 308 °C deep-sea hydrothermal system of the Suiyo Seamount, Izu-Bonin Arc, Pacific Ocean. Earth Planet Sd. Lett. 2004, 219, 147—153. 

There are many possibilities in the air, in the sea, on the shallow seafloor, on the deep seafloor, near on-land hydrothermal systems around andesite volcanoes (variable, intermediate to low pH), near on-land hydrothermal systems around koma-tiite volcanoes and hot ultramafic rocks (alkaline), near deep-water hydrothermal systems (acid), near carbonatite-driven hydrothermal systems (which could be phosphoms-rich), in hydrothermal systems under ice caps, in shallow-water tidal muds, anywhere else that is fancied. 

Only deep-sea hydrothermal vents and cold-seeps are discussed in this chapter. Shallow vents and seeps are known from a variety of locations, from the littoral zone to several tens of metres (e.g. Holm, 1987 Jensen etal., 1992 Dando etal., 1994a,b, 1995). Shallow vents have many differences from their deeper counterparts. They lack metal-rich and extreme high temperature fluids, as well as large-scale mineral deposits. They also lack typical hydrothermal vent animals. Biomass production in both systems is lower than at deep-sea vents and deep... 

Gain, F., Persson, J., Sugiyama, J. et al. (1992) The chitin system in the tubes of deep sea hydrothermal vent worms. Journal of Structural Biology, 109, 116-128. 

Flesslei R.R., Kaharl, V.A. (1995) The deep-sea hydrothermal vent community an overview , in Flumphris, S.E., Zierenberg, R.A., Mullineaux, L.S. and Thomson, R.E. (eds) Seafloor hydrothermal systems, Washington, DC American Geophysical Union, pp. 72-84. 

These four arguments have led scientists from various disciplines to look more closely at the theory of a possible biogenesis in hydrothermal systems in the deep sea. 

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