The Way of the Cell - Molecules, Organisms and the Order of Life
Franklin M. Harold, 2001
Oxford University Press.
This is the second time I am reading this book. At the first reading, a few years ago, I was terribly impressed not only with the writing style but also Harold's rational attitude to the scientific questions of origins and evolution of Life, which however does not advocate molecular fundamentalism. On this second reading, some 5 years later, I still like it a lot. But I can detect some overstatements and confusions.
In brief, Harold believes that we need to go beyond DNA and the genes they encode to understand Life. He talks about emergent behaviour, about how the chemiosmostic process that supplies energy to the cells is not specifically coded for in the genes, though the molecules that are involved are; he talks about what he calls 'morphogenetic fields' that are produced by chemical gradients within a cell and which map proteins and protein function to specific positions of the cell. Again these fields are not coded in the genes. He talks about how the very machinery of gene expression requires not only a host of genes, but also a bag, the lipid membrane, to localize all the players and give the cell some integrity. These membranes are also not specified in the genes but are directly inherited by the daughter cells from the parent. He states that evolution may also act on organisms as a whole (at least natural selection does) and not on the genes directly, though variation probably occurs mainly, if not solely in the genes. He describes epigenetic transfer of hereditary information, in which patterns of DNA methylation or protein phophorylation may be a vehicle to transfer this from one generation to the next. He also hints that protein folding is guided by some such morphogenetic field.
On the whole he make a convincing case for going beyond genes to understand Life. However he does appear to overstate the case at times. Richard Dawkins and others could probably interpret some of the above (including morphogenetic fields and protein folding, but may not epigenetic information) in terms of genes and variations in them being selected for fitness. Occasionally Harold appears to contradict himself, as for example when he says, towards the end of the book, that Life can finally be explained in terms of Physics and Chemistry, and maybe without any new 'biophysical' laws required.
Harold is a pleasure to read, with extremely lyrical writing. There were several sentences and phrases I wanted to memorize and maybe reproduce to my students. But unfortunately, I didn't and now I do not recall any of them. I wish I had written them down then and there. Maybe I should get a palmtop or some such device to do this. Or maybe I should just carry a slim notepad always. I will have the read the book once again, maybe a couple of years from now. But the book could age, and become somewhat out of date by then. I hope not though!
Franklin M. Harold, 2001
Oxford University Press.
This is the second time I am reading this book. At the first reading, a few years ago, I was terribly impressed not only with the writing style but also Harold's rational attitude to the scientific questions of origins and evolution of Life, which however does not advocate molecular fundamentalism. On this second reading, some 5 years later, I still like it a lot. But I can detect some overstatements and confusions.
In brief, Harold believes that we need to go beyond DNA and the genes they encode to understand Life. He talks about emergent behaviour, about how the chemiosmostic process that supplies energy to the cells is not specifically coded for in the genes, though the molecules that are involved are; he talks about what he calls 'morphogenetic fields' that are produced by chemical gradients within a cell and which map proteins and protein function to specific positions of the cell. Again these fields are not coded in the genes. He talks about how the very machinery of gene expression requires not only a host of genes, but also a bag, the lipid membrane, to localize all the players and give the cell some integrity. These membranes are also not specified in the genes but are directly inherited by the daughter cells from the parent. He states that evolution may also act on organisms as a whole (at least natural selection does) and not on the genes directly, though variation probably occurs mainly, if not solely in the genes. He describes epigenetic transfer of hereditary information, in which patterns of DNA methylation or protein phophorylation may be a vehicle to transfer this from one generation to the next. He also hints that protein folding is guided by some such morphogenetic field.
On the whole he make a convincing case for going beyond genes to understand Life. However he does appear to overstate the case at times. Richard Dawkins and others could probably interpret some of the above (including morphogenetic fields and protein folding, but may not epigenetic information) in terms of genes and variations in them being selected for fitness. Occasionally Harold appears to contradict himself, as for example when he says, towards the end of the book, that Life can finally be explained in terms of Physics and Chemistry, and maybe without any new 'biophysical' laws required.
Harold is a pleasure to read, with extremely lyrical writing. There were several sentences and phrases I wanted to memorize and maybe reproduce to my students. But unfortunately, I didn't and now I do not recall any of them. I wish I had written them down then and there. Maybe I should get a palmtop or some such device to do this. Or maybe I should just carry a slim notepad always. I will have the read the book once again, maybe a couple of years from now. But the book could age, and become somewhat out of date by then. I hope not though!
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