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Authors: Nicholas Mosley
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called a 'Lamarckian'. What he was supposed to believe in (it is impossible in such areas, as you say, to avoid the jargon) was the inheritance of acquired characteristics.
What Darwinists such as my father believed in (arguments about dogma go round and round; it is impossible also not to repeat oneself) was that parents can transmit through heredity only what they have inherited themselves - they cannot pass on the skills or faults or features that they have acquired during their lifetimes; though they can, of course, pass on something of these by teaching. Evolutionary jumps take place when mutations in genetic material occur by chance; 'chance' means here just what cannot be explained scientifically in terms of what is predictable. There was even a theory that genetic mutations might be caused by cosmic radiation, but this conjecture could not be tested.
Lamarckians (taking their name from a French biologist who lived in the early nineteenth century) claimed that it is impossible to explain evolution by chance occurrences: for such huge steps to have occurred as, for instance, the emergence of the human eye, there would have to have been such myriad interlocking coincidences as to be inconceivable: what possible evolutionary advantage could there have been in the emergence on their own of one or two still useless facets of the complex totality of the human eye which only functions when it is complete? For explanations to make sense there had to be taken into account the likelihood of some directing or at least coordinating force among the plethora of required mutations: and it did seem, yes, that this might be provided by the possibility of what had been of advantage to parents being in some way genetically passed on. This would not mean, for instance, that a parent who had lost a limb would pass on to an offspring this lack of a limb: Lamarckians suggested that only such characterises might be passed on as would be of advantage in coming to terms with the environment.
But this sort of talk was anathema to Darwinists, ostensibly because there was no means of explaining scientifically how this learning on the part of parents could be transmitted to the genetic material, the cells of which could be shown (or so it was believed)
to be quite separate from the cells of the other parts of the body. But it seems to me now (of course, no scientist talked like this at the time) that there was some rage or even terror amongst biologists at the suggestion that what a person had acquired (or not acquired!) during a lifetime might be passed on to offspring: what a burden of responsibility this would place upon a parent! Every failure would be perpetuated; every fault would make a person accountable for ever.
During the early years of the twentieth century the situation remained confused: neither Darwinists nor Lamarckians seemed able to answer the objections that each put up against the other. Then there was the rediscovery by people like my father of Mendelian genetics - theories about inheritance suggested by Mendel fifty years earlier but not at the time taken up. These described how innumerable small differences occurring naturally in genetic material could be seen, by an understanding and application of mathematics, to account for the larger changes in living forms seeming to occur just when a change in the environment, as it were, provoked or required them: it was as if (my mother had used an image that was coming into vogue at the time) there were indeed all sorts of latent mutations hanging about waiting to be encouraged to emerge from what might be called a 'gene pool'. This image, it was true, did not seem very explicit about what it actually referred to; but then experts such as my father could retreat behind their jargon - or behind their claim that such a matter could properly only be understood by mathematicians.
But then, just when geneticists like my father seemed to be getting the business sorted out, or at
What Darwinists such as my father believed in (arguments about dogma go round and round; it is impossible also not to repeat oneself) was that parents can transmit through heredity only what they have inherited themselves - they cannot pass on the skills or faults or features that they have acquired during their lifetimes; though they can, of course, pass on something of these by teaching. Evolutionary jumps take place when mutations in genetic material occur by chance; 'chance' means here just what cannot be explained scientifically in terms of what is predictable. There was even a theory that genetic mutations might be caused by cosmic radiation, but this conjecture could not be tested.
Lamarckians (taking their name from a French biologist who lived in the early nineteenth century) claimed that it is impossible to explain evolution by chance occurrences: for such huge steps to have occurred as, for instance, the emergence of the human eye, there would have to have been such myriad interlocking coincidences as to be inconceivable: what possible evolutionary advantage could there have been in the emergence on their own of one or two still useless facets of the complex totality of the human eye which only functions when it is complete? For explanations to make sense there had to be taken into account the likelihood of some directing or at least coordinating force among the plethora of required mutations: and it did seem, yes, that this might be provided by the possibility of what had been of advantage to parents being in some way genetically passed on. This would not mean, for instance, that a parent who had lost a limb would pass on to an offspring this lack of a limb: Lamarckians suggested that only such characterises might be passed on as would be of advantage in coming to terms with the environment.
But this sort of talk was anathema to Darwinists, ostensibly because there was no means of explaining scientifically how this learning on the part of parents could be transmitted to the genetic material, the cells of which could be shown (or so it was believed)
to be quite separate from the cells of the other parts of the body. But it seems to me now (of course, no scientist talked like this at the time) that there was some rage or even terror amongst biologists at the suggestion that what a person had acquired (or not acquired!) during a lifetime might be passed on to offspring: what a burden of responsibility this would place upon a parent! Every failure would be perpetuated; every fault would make a person accountable for ever.
During the early years of the twentieth century the situation remained confused: neither Darwinists nor Lamarckians seemed able to answer the objections that each put up against the other. Then there was the rediscovery by people like my father of Mendelian genetics - theories about inheritance suggested by Mendel fifty years earlier but not at the time taken up. These described how innumerable small differences occurring naturally in genetic material could be seen, by an understanding and application of mathematics, to account for the larger changes in living forms seeming to occur just when a change in the environment, as it were, provoked or required them: it was as if (my mother had used an image that was coming into vogue at the time) there were indeed all sorts of latent mutations hanging about waiting to be encouraged to emerge from what might be called a 'gene pool'. This image, it was true, did not seem very explicit about what it actually referred to; but then experts such as my father could retreat behind their jargon - or behind their claim that such a matter could properly only be understood by mathematicians.
But then, just when geneticists like my father seemed to be getting the business sorted out, or at
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