Graham Cairns-Smith

Alexander Graham Cairns-Smith (born November 24, 1931 - † August 26, 2016 in Uplawmoor ) was a chemist and molecular biologist at the University of Glasgow .

Cairns-Smith became known for his 1985 book Biological Messages. A detective story of evolution (original title: "Seven Clues to the Origin of Life"). In it he advocates the theory that the self-replication of soluble clay minerals is the step between inanimate matter and life . He rejects other theories such as chemical evolution , including the Miller-Urey experiment and the RNA world .

Cairns-Smith has also authored a book on the evolution of consciousness ( Evolving the Mind , 1996), in which he ascribes an important role in human thought to quantum mechanics .

Clay minerals as a transition between dead and alive

Cairns-Smith's theory states that soluble clay minerals are the step between dead matter and living things . His theory is as follows: Clay minerals are deposited in nature when soluble silicates are deposited. This allows the minerals to maintain their structure as they grow. They can break at some point, but keep growing. If numerous minerals with a certain external structure settle, they can damage their environment, which reduces the chances for future growth. For example, mineral structures that are particularly sticky can more easily create a silt base that is favorable for future deposits. It is conceivable that these effects lead to the formation of flat areas which are more likely to be exposed to the air. The air dries the minerals and the wind spreads them over a large area. In the random landing area, these particles would then start growing again, passing on their structure, namely one that creates flat plains. This would spread this structure very much over time. Although this is an inorganic and dead substance, over time certain crystal structures would prevail in a certain environment, which can be compared with natural selection .

This natural selection would ultimately also lead to the fact that particularly crystal structures would prevail that are able to bind special molecules to themselves (these molecules improve the replication potential). Quite complex proto-organic molecules can be catalyzed by the surface of the silicates . Ultimately, in this way, the complex organic molecules could take the “lead” over their “silicate transport boxes” and become an independent place for self-replication . If so, this could be seen as the first exaptation , the moment when complex molecules were first able to self-replicate and self-propagate with the help of crystals.

Cairns-Smith's theory is not accepted by most scholars. Richard Dawkins , however, mentions them in his book The Blind Watchmaker as an example of spontaneous generation .

Fonts

• Biological messages. A detective story of evolution . Fischer-Taschenbuch-Verlag, Frankfurt am Main 1993, ISBN 978-3-596-28719-2 .
• An approach to a blueprint for a primitive organism . In: Waddington (Ed.): The Origin of Life: Towards a Theoretical Biology, volume 1 . 1968, p. 57-66 .
• Genetic Takeover and the Mineral Origins of Life . Cambridge University Press, New York 1985, ISBN 0-521-23312-7 (First edition: 1982, reprint).
• Seven Clues to the Origin of Life. Cambridge . Cambridge University Press, New York 1985, ISBN 0-521-27522-9 .
• Evolving the Mind. On the Nature of Matter and the Origin of Consciousness . Cambridge University Press, New York 1996, ISBN 0-521-40220-4 .

Web links

• Academic website , University of Glasgow
• A bibliography of Cairns-Smith's origins of life publications , originoflife.net

Individual evidence

1. ^ Obituary - Graham Cairns-Smith, artist, scientist and author of Seven Clues to the Origin of Life