Any pride I had in my once resilient immune system has been shattered by this latest cold from which I'm only just recovering a week later, as opposed to the normal 48-hour recovery period that I'm used to (barring a severe viral infection picked up in China in 2005 that lingered long time). Despite feeling rotten, the upside to being ill is definitely recapturing time from The Man to seek one's own entertainment. Resisting the siren voices of Loose Women and daytime TV, I found time to dust off the acoustic guitar, read the odd frothy novel (Starter for Ten by David Nicholls), watch one DVD box set (HBO and David Simon's Generation Kill) and start another (Our Friends In The North). Ever conscious of my need to study too, I beavered away at my biology textbook and read an incredible book, Life Ascending by Nick Lane, which examines 10 evolutionary inventions essential to life on our blue-green marble floating in infinite space.
Winner of the Royal Society Prize in 2010, the book is split into 10 chapters: Origin of Life, DNA, Photosynthesis, Complex Cell, Sex, Movement, Sight, Hot Blood, Consciousness and Death. Not for a second would I claim to have understood all that was written in this book, especially when the focus was on biochemistry or the latest research on life processes like the Krebs Cycle, but what I did comprehend was full of insights. Life Ascending is also very well written with phrases like, “thermodynamics makes the world go round, as the blood lust of reactions”. Nick Lane makes a powerful case for hydrothermal vents, not the primordial soup, as the likely site of life's origin. Life in the "smokers" on the ocean bed is grotesque, a world of Hieronymous Bosch characters. David Attenborough's latest BBC documentary, First Life, also supports this theory of the first genesis of life taking place in the unique environment of underwater vents, and biochemists now have a clearer idea of the mechanism behind this complex process.
Life's next big evolutionary step was photosynthesis, originating in cyanobacteria (blue-green algae) and making oxygen the most useful “waste” product imaginable. Photosynthesis and respiration are equal and opposite reactions, and the wealth of oxygen created by algae dramatically altered the fortunes of our early life ancestors and encouraged biodiversity. Ever since, “all our energy is a beam of sunlight set free from its captive state in food”. As a result, oxygen levels have remained at around 21% for much of earth's long history, producing the essential but precarious balance of Gaia between respiration and photosynthesis, erosion and carbon burial. Today, cyanobacteria are the only known group of bacteria that can split water via the oxygenic form of photosynthesis, and are key to biofuel research. Solving how we artificially prise apart the hydrogen and oxygen in water is key to solving the climate needs of the planet.
Nick Lane also refers to some of the other popular science books out there like Primo Levi's The Periodic Table, but points to a few areas where Levi got his chemistry of photosynthesis wrong. In particular, a flashing pack of solar light does not activate carbon dioxide, it can be activated just as well at night, nor is carbon separated in an instant from its oxygen. In fact, the oxygen comes from water not carbon dioxide. All this starts to get quite complex for the lay reader and I paraphrase the section below as an illustration:
"In plants, the business of electron extraction takes place in the chloroplasts, with the Z-scheme at the heart of the process. The sun provides organic matter and ATP (“two free lunches”) in equal measure. A photon of light hits the first photosystem and blasts an electron up to a higher energy level, with the energy of this electron then cascading down in a series of small molecular steps to provide the energy needed for ATP, and then back at a lower energy level the electron arrives at the second photosystem where a second photon blasts it up a second time to a higher energy level. From this second higher level, the electron is transferred to carbon dioxide in the first step to creating a sugar."
This link did help me understand this essential life process a little better, but I must admit to struggling. Readers are assured that the simple forms of photosynthesis are mosaic-like in character. Both early forms plugged a new transducer, chlorophyll, into existing molecular machinery. In one case, this machinery converted carbon dioxide into sugars, in the other it produced ATP. So, how did the two come together in the Z-scheme to split the ultimate fuel, water? On this topic, even the well-read author confesses to not knowing the answer.
Subsequent chapters and are no less challenging, but I found each one full of insights. For instance, in the "hot blood" section, we're told that the main advantage that mammals and birds have over cold-blooded reptiles is stamina. Higher metabolic rates confer greater stamina and bigger brains, whereas reptiles only have speed to rely on but quickly get exhausted. Having 4-chambered hearts ensure high aerobic respiration for mammals, with oxygenated blood flowing from the lungs to the heart, then pumped out again to the brain and muscles. Also news to me was that birds are very likely descended from therapod dinosaurs. According to the study of amino acid chains in bones, the closest living relations to T-Rex are chickens and ostriches.
In the chapter on consciousness, we start with the Pope's desire to separate humans into body (scientifically knowable) and spirit (mystical), what Stephen Jay Gould called the Non-Overlapping Magisteria of science and religion. Nick Lane doesn't share this view and highlights areas where science and consciousness overlap, even though he confesses we still know little about the brain. Lots of fine scientific minds have turned to this subject in later years, and he outlines some of the small but significant breakthroughs. As in most areas of science, experiment is the only path to discovery, but the complexity and inaccessibility of the brain remains the main barrier to further research.
Ending the book with a chapter on death might sound depressing, but here I found most cause for optimism. A strong body of evidence now points to the fact that low free radical leak from mitochondria in our cells equates to a longer life, irrespective of metabolic rate. Any breakthroughs in this area might keep ageing and all its related diseases at bay for longer. In addition, calorie restriction is a key defence mechanism against ageing, even more so than potential wonder drugs like resveratrol. So my take-home lesson was eat less, invest in genome and biofuel research, and be thankful for algae and all life's survivors and innovators that got us here today.
Winner of the Royal Society Prize in 2010, the book is split into 10 chapters: Origin of Life, DNA, Photosynthesis, Complex Cell, Sex, Movement, Sight, Hot Blood, Consciousness and Death. Not for a second would I claim to have understood all that was written in this book, especially when the focus was on biochemistry or the latest research on life processes like the Krebs Cycle, but what I did comprehend was full of insights. Life Ascending is also very well written with phrases like, “thermodynamics makes the world go round, as the blood lust of reactions”. Nick Lane makes a powerful case for hydrothermal vents, not the primordial soup, as the likely site of life's origin. Life in the "smokers" on the ocean bed is grotesque, a world of Hieronymous Bosch characters. David Attenborough's latest BBC documentary, First Life, also supports this theory of the first genesis of life taking place in the unique environment of underwater vents, and biochemists now have a clearer idea of the mechanism behind this complex process.
Life's next big evolutionary step was photosynthesis, originating in cyanobacteria (blue-green algae) and making oxygen the most useful “waste” product imaginable. Photosynthesis and respiration are equal and opposite reactions, and the wealth of oxygen created by algae dramatically altered the fortunes of our early life ancestors and encouraged biodiversity. Ever since, “all our energy is a beam of sunlight set free from its captive state in food”. As a result, oxygen levels have remained at around 21% for much of earth's long history, producing the essential but precarious balance of Gaia between respiration and photosynthesis, erosion and carbon burial. Today, cyanobacteria are the only known group of bacteria that can split water via the oxygenic form of photosynthesis, and are key to biofuel research. Solving how we artificially prise apart the hydrogen and oxygen in water is key to solving the climate needs of the planet.
Nick Lane also refers to some of the other popular science books out there like Primo Levi's The Periodic Table, but points to a few areas where Levi got his chemistry of photosynthesis wrong. In particular, a flashing pack of solar light does not activate carbon dioxide, it can be activated just as well at night, nor is carbon separated in an instant from its oxygen. In fact, the oxygen comes from water not carbon dioxide. All this starts to get quite complex for the lay reader and I paraphrase the section below as an illustration:
"In plants, the business of electron extraction takes place in the chloroplasts, with the Z-scheme at the heart of the process. The sun provides organic matter and ATP (“two free lunches”) in equal measure. A photon of light hits the first photosystem and blasts an electron up to a higher energy level, with the energy of this electron then cascading down in a series of small molecular steps to provide the energy needed for ATP, and then back at a lower energy level the electron arrives at the second photosystem where a second photon blasts it up a second time to a higher energy level. From this second higher level, the electron is transferred to carbon dioxide in the first step to creating a sugar."
This link did help me understand this essential life process a little better, but I must admit to struggling. Readers are assured that the simple forms of photosynthesis are mosaic-like in character. Both early forms plugged a new transducer, chlorophyll, into existing molecular machinery. In one case, this machinery converted carbon dioxide into sugars, in the other it produced ATP. So, how did the two come together in the Z-scheme to split the ultimate fuel, water? On this topic, even the well-read author confesses to not knowing the answer.
Subsequent chapters and are no less challenging, but I found each one full of insights. For instance, in the "hot blood" section, we're told that the main advantage that mammals and birds have over cold-blooded reptiles is stamina. Higher metabolic rates confer greater stamina and bigger brains, whereas reptiles only have speed to rely on but quickly get exhausted. Having 4-chambered hearts ensure high aerobic respiration for mammals, with oxygenated blood flowing from the lungs to the heart, then pumped out again to the brain and muscles. Also news to me was that birds are very likely descended from therapod dinosaurs. According to the study of amino acid chains in bones, the closest living relations to T-Rex are chickens and ostriches.
In the chapter on consciousness, we start with the Pope's desire to separate humans into body (scientifically knowable) and spirit (mystical), what Stephen Jay Gould called the Non-Overlapping Magisteria of science and religion. Nick Lane doesn't share this view and highlights areas where science and consciousness overlap, even though he confesses we still know little about the brain. Lots of fine scientific minds have turned to this subject in later years, and he outlines some of the small but significant breakthroughs. As in most areas of science, experiment is the only path to discovery, but the complexity and inaccessibility of the brain remains the main barrier to further research.
Ending the book with a chapter on death might sound depressing, but here I found most cause for optimism. A strong body of evidence now points to the fact that low free radical leak from mitochondria in our cells equates to a longer life, irrespective of metabolic rate. Any breakthroughs in this area might keep ageing and all its related diseases at bay for longer. In addition, calorie restriction is a key defence mechanism against ageing, even more so than potential wonder drugs like resveratrol. So my take-home lesson was eat less, invest in genome and biofuel research, and be thankful for algae and all life's survivors and innovators that got us here today.
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