If water is the cradle of life, then oxygen is its engine. Without oxygen, life on Earth could not have advanced beyond a slime in the oceans, and would probably have ended its days in the ostensible sterility of Mars or Venus. With oxygen, life flourished in all its wonderful variety. With it, too, came the evolution of ageing and death. This book is about life, death and oxygen: about how and why life produced and adapted to oxygen; about the evolutionary past and future of life on Earth; about energy and health, disease and death, sex and regeneration, and about ourselves. Life’s adaptations to oxygen began nearly four billion years ago, and are still written into our innermost constitution. Adaptations to the opportunities and challenges posed by oxygen link the extremes of the living world, from bacterial tolerance to cosmic radiation to the organisation of our own bodies. Thinking about life through the prism of oxygen explains conundrums like the evolution of photosynthesis, the sudden appearance of large animals in the Cambrian explosion, the flight of dragonflies as big as hawks, the origin of two sexes, the accelerated ageing of cloned animals like Dolly the sheep, and the long lives of bats and birds. Oxygen takes a panoramic view of life on Earth. Drawing on fields as diverse as geology, cosmology, chemistry, biology and medicine, it explains why oxygen bridges the gap between the two great facets of life, metabolism and reproduction. Oxygen is shown to be a primordial sensor of health and vitality, which still orchestrates our defences against physiological stresses such as radiation and infection. This unusual perspective offers striking insights into the nature of ageing, disease and death, culminating in a new synthesis, the Double Agent Theory of ageing. We see why neither the Human Genome Project nor dietary antioxidant supplements can solve the problems of old age, and why infectious diseases and the emerging field of mitochondrial medicine might lead to cures for heart disease, cancer and dementia. The result is an entertaining and thought-provoking read that challenges key assumptions underlying modern medical research.
About the Author
Nick Lane trained as a biochemist at the University of London (Imperial College), taking his PhD on oxygen free radicals and metabolic function in organ transplants at the Royal Free Hospital. He is honorary research fellow at University College London and strategic director at Adelphi Medi Cine, a medical multimedia company, where he is responsible for developing interactive approaches to medical education. He specialises in explaining recent scientific and medical advances to both doctors and patients. Nick Lane has published widely in international peer reviewed journals, including The BMJ and The Lancet. In addition to Oxygen, he is co-editor of the cryobiology textbook Life in the Frozen State.
A lot of information about a lot of different topics!, January 28, 2004
Doctor Lane’s own background is in biochemistry, and his research focus has been on oxygen free radicals and metabolic function in organ transplants. Not surprisingly he went into some detail about the free radical cascade that affects cellular metabolism and DNA integrity. I found this somewhat difficult to understand as I have only a very rudimentary grounding in organic chemistry. Still I have to admit that I know somewhat more about the process than I did before reading this book.
Probably because I know significantly more about geology and paleontology, I enjoyed more fully the author’s synthesis and analysis of what we know of the geological and biological development of our atmosphere and our planet. Some of this material was familiar to me from other sources: Certainly that O2 can actually be a "poison" I know from managing patients with ARDS (adult respiratory distress syndrome) on mechanical ventilators with 100% O2; that the earth went through a series of green house earth/snowball earth phases early in its history I had learned from Ward and Brownlee’s book Rare Earth; that life had begun almost as early as it was able and much earlier than had been previously believed, I was aware of from works by Gould, Schopf, and others; and that the mitochondria may once have been free-living, aerobic organisms that formed a symbiotic relationship with anaerobic organisms was known to me from my past exposure to microbiology in a nursing class.
New to me however, was the concept that gigantism may have been a means of limiting the negative effects of a periodic increase in oxygen in the environment, as Dr. Lane suggests in his chapter on The Bolsover Dragonfly. Although I had read an article that suggested that the immense sizes achieved by some of the dinosaur species might have been due to a higher percent of O2 at the time, I had also understood that it was because oxygen was a "good" thing, an opportunity of sorts. Lane points out that the negative effects of oxygen on tissues and DNA through the free radical cascade might have been ameliorated by an increased size. An animal–or one presumes also a plant–that increased its size might have been able to distribute negative effects over a greater body mass. One wonders if the rise of the mammalian mega fauna of the ice ages and their sudden almost catastrophic disappearance might not also have been due to some temporary fluxuation in the oxygen level of their atmosphere. (In which case the early Native Americans could be once and for all exonerated of having liquidated them, since their demise would have been dictated by a return to a baseline oxygen level!) If this were the case, one might also question what type of changes might be expected among our own kind as a result of such an increase and decrease of atmospheric oxygen.
I found the doctor’s ideas on the trade off between sexual reproduction and immortality a unique approach to the topic of aging. Some of this information–the studies of animal reproduction rates, predation, and age at death, for instance–was known to me. Dr. Lane’s discussion brought it together in a much more complete way.
Certainly the concept of sexual reproduction being one of life’s mechanisms of perpetuating the fragile, complex organic molecules (DNA) in an oxidative environment was interesting. I had read Ridley’s proposal that sexual reproduction evolved as a means of resisting bacterial infection, but Lane’s suggests why it began as early as the DNA swapping behavior among early single eukaryotic cells. That the massive increase in biological diversity was an indirect product of the release of oxygen into the atmosphere, is truly an amazing thought. In the event as Lane makes claim in his subtitle, oxygen was truly "The Molecule that made the World."