29 September 2014

"She tosses her creatures out of nothingness..."

Research into the origin of life benefits from thinking about whole planets, says Andy Knoll:
Planetary history is the context for thinking about the history of life on a planet. When we explore Mars, it's our experience on Earth that informs that exploration. When Dimitar Sasselov, Dave Charbonneau and Dave Latham give us a sense of planetary atmospheres from Kepler, it will be our understanding of relationships between life and environment that will inform our interpretation of those atmospheres. It's hard for me to imagine efforts to understand either the origin of life on this planet or the distribution of life through the universe that don't revolve around the nature of planets.
as well as specific conditions on those planets:
Life was probably born in a small pond or lake, Jack Szostak believes...Rain-fed pools provide a fresh water environment, compatible with the delicate cell membranes formed from simple fatty acids, which would be destroyed instantly in the salty oceans. Some such pond was the place where crucial elements were mixed, heated and cooled in the right sequence to become life. Inanimate molecules, congregated together inside a fatty skin, somehow became capable of replication, and of evolution: the definition of life, as Szostak sees it. 
Very likely, Szostak says, life began near a hydrothermal vent: an underwater spout of hot water, flowing into the cold water of an icy lake, much like modern Yellowstone Lake in winter. This, he believes, was the oven and freezer where the ingredients of life were cooked, cooled, thawed in the order required for nucleic acids to go through cycles of replication, and for fatty acid membranes to allow nutrients to enter into the cell.

The quote at the top of the post is from one of Goethe's aphorisms on nature as cited by T. H. Huxley.

Image: Baobab trees on a mushroom island in Bay of Moramba, Madagascar, by SebastiĆ£o Salgado

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