Nick Lane, "The Vital Question"

.

 

 

Nick Lane, "The Vital Question: Energy, Evolution, and

the Origin of Comples Life" (2015)

 

몇 년 전에 읽은 저자의

"Life Ascending: The Ten Great Inventions of Evolution" (2009)도

흥미로웠는데 이 책은 그 이후의, 현재도 진행 중인, 저자의 연구

내용 -- 그의 가설 -- 을 상당히 자세히 설명하고 있어서 더욱

관심을 끈다. 논리를 명확히 이해하려면, 특히 마지막 두

장은 한 번은 더 주의 깊게 읽어야겠다.

 

The Guardian 서평

 

뉴욕 타임즈 서평

 

 

(20세기에 생물학의 혁명적인 아이디어 하나를 낸 것으로 책에 언급된

Lynn Margulis의 책을 읽은 기억이 나는데 맞다:

Lynn Margulis and Dorion Sagan, "Acquiring Genoms" (2002))

 

 

아래는 책에서:

 

The complex cells did not evolve by 'standard' natural selection, [Lynn] Margulis argued [in 1967], but in an orgy of cooperation, in which cells ... got inside of each other.... Marguis talked about endosymbiosis. (p. 5)

 

The use of cross-membrane proton gradients to power cells were utterly unanticipated, First proposed in 1961 and developed over the ensuing three decades by one of the most original scientists of the twentieth century, Peter Mitchell, this conception has been called the most counterintuitive idea in biology since Darwin. (p. 13)

 

There are two aspects to the energy of life that are . First, all cells derive their energy from just one particular type of chemical reaction known as a redox reaction, in which electrons are transferred from one molecule to another. Redox stands for 'reduction and oxidation'.... As the donor passes on electrons, it is said to be oxidised. (p. 64)

 

The second unexpected aspect to the energy of life is the detailed mechanism by which energy is conserved i the bonds of ATP. Life doesn't use plain chemistry, but drives the formation of ATP by the intermediary of proton gradients across the membranes. (p. 65)

 

I will argue that chemiosmotic coupling constrained the evolution of life on earth to the complexity of bacteria and archaea for billions of years. A singular event in which one bacterium somehow got inside another one, overcame these endless energetic constraints on bacteria. That endosymbiosis gave rise to eukaryotes with genomes that swelled over orders of magnitude, the raw material for morphological complexity. The intimate relationship between the host cell and its endosymbionts (which went on to become mitochondria) was, I shall argue, behind many strange properties shared by eukaryotes. (p. 86)

 

All living organisms are sustained by far-from-equilibrium conditions in their environment: we, too, are dissipative structures. The continuous reaction of respiration provides the free energy that cells need.... Cell structures are forced into existence by the flux of energy and matter. The parts can be replaced but the structure is stable and will persist for as long as the flus persists. (p. 95)

 

Six basic properties are shared by all living cells on earth. (p. 96)

 

Energy is far less forgiving than genes.... You share some of your genes with the tree ... but you and that tree parted company very early in eukaryotic evolution, 1.5 billion years ago, each following a different course permitted by different genes, the product of mutations, recombination, and natural selection.... Genes are almost infinitely permissive: anything that can happen will happen.But that tree has mitochondria too, which work in much the same way as its chloroplasts, endlessly transferring electrons down its trillions upon trillions of respiratory chains, pumping protons across membranes as they always did. As you always did.... Your mitochondria passed from your mother, ... her most precious gift, the gift of living that goes back unbroken, unceasing, generation on generation, to the first stirrings of life ..., 4 billion years ago.... Death is the ceasing of electron and proton flux.... life is for the living. living needs an unceasing  flux of energy. (pp. 289-290)