jeudi 22 janvier 2009

「生命を定義する」 Définir la vie (10)

5 février 2008

Bruce Weber "What is life? Defining life in the context of emergent complexity"

Shelly (1822) "The Triumph of Life"
  the last poem: "Then. What is life? I cried."

Life was problematic for Democritean philosophers, but not for Aristotelians (= living as paradigma).

For Descartes's dualism, problematic

Sir Frederick Gowland Hopkins first prof of Biochem at Cambridge U
 rejects naive reductionists
1913; cell as chemical machine; life is whole of cell

Debate: vitalist vs. mechanist

 1930; Lancelot Hogben : mechanist
 1931; JBS Haldane : vitalist

JH Woodger: living organism not life; origin of life is out of science

1944: Schrodinger "What is life?"
 aperiodic crystal: order from order
 biological molecules: order from disorder
  internal system

1959: Oparin (Moscow meeting)
● templates for replication & for catalysts
● some mechanisms by which autonomy arises
● some mechanisms of reproduction

Darwin's public stance on origin of life: "Who cares!"

Ernst Mayr
: reductionist & emergentist
Alex Rosenberg: Darwinian reductionist, emergentist (scientific facts に基づいて考え直した) new modern Darwinism

Serial assembly of perfect parts is not efficient; the importance of the whole

1993: Stuart Kauffman's model for origin of life
"Origins of Order: Self-Organization and Selection in Evolution"

1991: Deamer's Protocell model (J Mol Evol 33:207-8)

transition from non-living to living
 Rasmussen, Science 303:963, 2004
 Pross, J Theor Biol 220: 393, 2003

 Luisi (2006): The emergence of life; origin of life & evolution of the biosphere

生命が地球で生れたと決めてかからずに、exobiology にも目をやる

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