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Lifelines (review)

This page contains a book review by Athel Cornish-Bowden of Lifelines: Biology, Freedom, Determinism by Steven Rose (1997), Alan Lane, the Penguin Press, Harmondsworth, ISBN 0713991577, available from amazon.co.uk; published in the USA by Oxford University Press, New York under the title Lifelines: Biology beyond Determinism, ISBN 0195120353, available from amazon.com

This review appeared as a part of multi-author review in Behavioral and Brain Sciences 22 (1999), together with reviews by 29 other reviewers (on pp. 885–912), followed by a response from Rose (pp. 912–921; see below). The review is confined to the central biochemical issue in the book, as it was written in the knowledge that other reviewers would deal with other aspects.

Metabolic complexity has
no bearing on genetic determinism

Abstract: Metabolic systems are complicated, and contain very large numbers of interacting reactions and many internal regulatory mechanisms. This does not, however, prevent the genetic composition of an organism from influencing its behavior, nor does it preclude the possibility that some aspects of its behavior may be amenable to simple explanations.

In 1774, Leonhard Euler claimed at the court of Catherine the Great that he could prove the existence of God, silencing his opponent, Denis Diderot, with the following challenge: Sir, (a + bn)/n = x, hence God exists; reply (quoted by Singh 1998). Like Diderot, Rose finds algebra hard to follow (p. 160) and might find it just as difficult to recognize the irrelevance of Euler's argument to the proposition it was supposed to prove. Rose's own style of discussion is similar, however, apparently in the hope that his readers will be sufficiently ignorant of biochemistry to think that his emphasis on its complexity has some bearing on the question of whether genes influence behavior.

Books that set out to explain why organisms behave as they do describe observations of behavior on almost every page. The books of Richard Dawkins, whom Rose selects as his special target, illustrate this well: readers can reject all of the author's interpretations while remaining fascinated by the purely factual information that these books contain. How one can hope to convince anyone of the truth of a theory without supporting it with abundant facts? Yet hard biological information is extremely sparse in Rose's book. There is a great deal about what he thinks of other biologists' opinions, but almost no observations from behavioral biology. Nonetheless, in his preface (p. x) he aligns himself with the practising biologists who spend a significant part of every working day thinking about and designing experiments, dismissing Dawkins and Daniel Dennett as people who either no longer do science or never did it. What a pity, therefore, that he chose to include so little of the experimental basis of his ideas in his book. There are a few vague remarks about how chicks behave, and that's about it.

Rose claims throughout the book to be a biochemist, and in the remainder of this review I shall concentrate on the section (pp. 158–166) that deals with the complexity of metabolic networks and underlies the suggestion at the end of the book (p. 307) that genes are just individual workers in the great molecular democracy of the cell. As this section occurs in a chapter with the same title as the book, it is fair to regard it as the core of the book.

However, even as a standard biochemical account of the basic ideas of metabolic regulation, divorced from its role in the whole thesis, it is peculiar. In a muddled account of enzyme catalysis that does not contain any algebra Rose confesses that he finds the algebraic relationship between a reaction rate and a rate constant hard to grasp. He then presents metabolic regulation in terms of the tired old myth of the rate-limiting reaction, saying that in practice it often turns out that the rate-limiting step is one of the first in the sequence — obviously advantageous so far as the cellular economy is concerned: does it turn out, or is it assumed without considering any other possibility? The enzyme phosphofructokinase is asserted in innumerable textbooks to be the rate-limiting enzyme for glycolysis. If it were, then overexpressing it would increase the glycolytic flux, but even though the relevant experiments were done in yeast more than a decade ago (Heinisch 1986), and have since been repeated in other organisms, the results — no detectable increase in glycolytic flux when phosphofructokinase is overexpressed 3.5-fold — have yet to be taken seriously by the hordes of biotechnologists in search of the mythical rate-limiting enzymes.

Rose appears to be conscious that his account is faulty, because at the end of it he quotes Kacser & Burns (1979) to the effect that control is shared among all the enzymes of a system. But does he mean the mea culpa that follows? If Kacser & Burns are right then what was the point in wasting some pages on a muddle? If they are wrong then why are they being quoted? Presumably the attraction of their paper lay more in its title and some quotable sentences than in any serious study of its content.

If these pages have any point at all it is to establish that metabolism is complicated, involving very large numbers of interacting reactions. True enough, but what does that have to do with the idea that genes can affect behavior? A system can be highly complicated, with many internal regulatory devices, yet its behavior may still be amenable to explanation in terms of a particular set of external influences: does anyone doubt that the path taken by an airliner is affected by the actions of its pilot, or must one just say that it is a complicated device and the pilot is just one of many components in its democratic organization?

References

Heinisch, J. (1986) Isolation and characterisation of the two structural genes coding for phosphofructokinase in yeast. Molecular and General Genetics 202:75–82 [context]

Kacser, H. & Burns, J. A. (1979) Molecular democracy: who shares the controls? Biochemical Society Transactions 7:1149–1161 [context]

Singh, S. (1998) Fermat's last theorem. Fourth Estate [context]

Author’s Reply

In his reply to the whole set of reviews [Behavioral and Brain Sciences 22, 912–921 (1999)], Rose made the following comments in relation to the above:

What Lifelines is about

[...] There is little enough about ecology and population in the book, which is to be regretted, as some reviewers point out, but this reflects my own perspective and limitations as a biochemist turned neuroscientist (pace Cornish-Bowden I don’t just claim to be a biochemist). I confess to some surprise that these core themes occupied so few of the reviewers, who preferred to respond to the periphery rather than to the centre. Indeed almost the only person who did address them was Cornish-Bowden, who sadly totally misunderstands the argument. He claims that I first provide a simplistic account of rate-limiting reactions in biochemistry, then correct that account, and finally argue that this means that genes are irrelevant to behaviour. In fact I do nothing of the sort: the discussion of rate-limiting reactions is, as my text makes very clear, a self-critical comment on early editions of a teaching text of mine, The chemistry of life (1991). The second is a description of the Kacser–Kauffman approach to metabolic complexity, which forms part of the explanation of why gene function and action can only be understood in the context of the metabolic web with in which they are enmeshed; it is only remotely connected with the discussion of genes and behaviour, and nowhere in Lifelines or anywhere else have I ever made the absurd statement that genes have nothing to do with behaviour. Cornish-Bowden must read more carefully. [...]

I should be pleased, I suppose, to be the only one (out of 30!) reviewers to identify what Lifelines is about and to address what its author regards as its core themes, even if I totally misunderstood the argument. It apparently has not occurred to Rose that if only one out of 30 reviewers identified the core themes of the book and that one totally misunderstood the argument then he may have been guilty of writing in a way that invites misunderstanding. In any case, I do not believe that I misunderstood this argument; I just found it ridiculous. Rose thinks that his text made it perfectly clear that pp. 158–163 were intended as a piece of self-criticism, but this is not clear at all (and especially it would not be clear to the general reader for whom the book was written). The nearest Rose comes to criticizing these pages is to say that they are far too simple (p. 163), but I was not criticizing them for being too simple but for being muddled, old-fashioned and wrong. In his response, he implies that the criticism applies only to the early editions of The chemistry of life, but in Lifelines itself it is clear that it applies to the recent editions as well. Rose says that nowhere in Lifelines or anywhere else [has he] ever made the absurd statement that genes have nothing to do with behaviour, and that I need to read more carefully. So indeed does he, as nowhere in my review do I say that he made such a statement, and maybe he is confusing my review with the one immediately following it, where Wim E. Crusio has the following to say (p. 890):

It is almost as if he wants to argue that genes and behavior have nothing to do with one another and that if genes do influence behavior, then they only do so in animals and surely not in man.

Perhaps this is the absurd statement that Rose has in mind, but in any case my quoting it is no criticism of Crusio, with whom I fully agree that it is indeed almost as if Rose is wanting to argue this.

This tendency to attack opponents for saying things that they have not said, and for falsely accusing them of committing the same fault themselves, is actually quite characteristic of the book as a whole and of Rose’s other writings, not to mention those of some of his allies who are more well known to the general public than he is himself. Among these the preeminent example is Steven J. Gould, whose attractive style of expressing his ideas (quite different from the dour and joyless approach favoured by Rose) has led many non-biologists into the error of supposing him to present the reasoned face of modern biology: anyone who has been misled in this way can hardly do better than read the devastating critique written by John Tooby and Leda Cosmides.

Other reviews

As far as I know none of the other 30 reviews that appeared in Behavioral and Brain Sciences are yet available on the web. A few of them liked the book, but most did not, albeit for a variety of reasons. There are, however, some web sites that express more favourable opinions, written from points of view that range from the Christian to the communist. To be fair, I have also come across one reviewer who works in the biological sciences who liked the book, though as he refers to its author as a highly respected biochemist I wonder how many biochemists he has asked, or whether he just took Rose’s self-assessment at face value.