Wednesday Book Club: Genome

Wednesday, 3 December 2008 — 11:28pm | Book Club, Literature, Science

This week’s selection: Genome: The Autobiography of a Species in 23 Chapters (1999) by Matt Ridley.

In brief: A dense but concise tour of the twenty-three chromosomes of the human genome, Genome is better consumed as a chapter-by-chapter survey of modern genetics than as a unified book-length argument. All the same, Ridley’s primer advances a responsible optimism toward genetic science in a manner that openly resists sensationalism.

(The Wednesday Book Club is an ongoing initiative of mine to write a book review every week. I invite you to peruse the index. For more on Genome, keep reading below.)

Matt Ridley’s journalistic credentials come from the scientific wing of The Economist. If you are at all familiar with the science-and-technology section of the weekly newsmagazine, you already have a good idea of what to expect from Genome: concise popular explanations of modern advances that assume little a priori fluency in scientific vocabulary, buttressed with editorial commentary on the ramifications of new discoveries on political and social policy.

As the subtitle indicates, Genome is divided into twenty-three chapters, each one loosely corresponding to the chromosome pairs that are numbered from 1 through 22 in order of length (with the X and Y sex chromosomes interposed between Chapters 7 and 8 to reflect the length of chromosome X). The correlation between a chromosome and the chapter that bears its number is of incidental importance. In most cases, the relevant chromosome is a centre of gravity for the discussion around it: the gene on chromosome 9 that determines ABO blood type inspires a broad exploration of infectious disease in Chapter 9, whereas Chapter 11’s explanation of the gene on chromosome 11 that produces dopamine receptors unfolds into an assessment of the degree to which brain chemistry influences personality.

Ridley’s distillations of genetic discoveries vary in lucidity throughout. There is often a lot of terminology to absorb at once—the Introduction alone performs the unenviable task of sorting out replication and translation, introns and exons, DNA and RNA, and much more, all in the span of four pages—but it is hard to imagine how Ridley could omit or condense any more of it than he does and still present his case studies with enough specificity to connect to the larger thematic ideas in the book.

Frequently, Ridley falls back on the tried-and-tested analogy between genes and natural language: we are told from the outset to think of the genome as a book, where the twenty-three chapters are chromosomes, the words are codons, and the letters are bases. In Chapter 13, which discusses the genetics of genealogy, the connection is more concrete: the evolutionary divergence of genes and the historical dispersal of languages serve as simultaneous and mutually corroborating indicators of human migratory patterns. Ridley also uses the parallels with language to draw attention to the linear and digital nature of the genome’s four-character alphabet, which makes genetics conveniently suited for computational investigation.

In spite of the soundness of the linguistic analogy, Ridley is also quick to acknowledge the limitations of representing the genome in analogous terms, and is aware of how easy it is for the popular imagination of scientific concepts to be misled by a poor choice of words. He outright refuses to use the word “blueprint”, as it implies a two-dimensional picture and encourages a part-for-part, segment-for-segment correspondence between genes and functions, which is not at all the case; as he puts it, “each sentence of a recipe book does not make a different mouthful of cake.” Late in the book, Ridley comments on the oddity of representing genes as the subjects of sentences, as if they are the ones running the show—although given the chapter on genes that act out of self-interest and form bodies for their own propagation and survival, maybe that suggestion isn’t far off.

The segmentation of the book into what are ultimately twenty-three distinct articles proves to be an obstacle to the delivery of any singular thesis, and no grand picture of the human genome coheres at the end. This is not to say that Genome is without message, as there are several lessons that Ridley reiterates on multiple occasions. We are reminded time and again, in an uppercase bellow, that “GENES ARE NOT THERE TO CAUSE DISEASES.” In other words, we should not regard genetic variations as defective when they correspond to our susceptibility to certain diseases, nor should we read the product of the Human Genome Project—an interpolated consensus of human gene sequences—as a definitive ideal of normalcy:

The Human Genome Project is founded upon a fallacy. There is no such thing as ‘the human genome’. Neither in space nor in time can such a definite object be defined. At hundreds of different loci, scattered throughout the twenty-three chromosomes, there are genes that differ from person to person. Nobody can say that the blood group A is ‘normal’ and O, B and AB are ‘abnormal’. So when the Human Genome Project publishes the sequence of the typical human being, what will it publish for the ABO gene on chromosome 9? The project’s declared aim is to publish the average ‘consensus’ sequence of 200 different people. But this would miss the point in the case of the ABO gene, because it is a crucial part of its function that it should not be the same in everybody. Variation is an inherent and integral part of the human— or indeed any—genome.

[…]

The genome that we decipher in this generation is but a snapshot of an ever-changing document. There is no definitive edition.

Taken out of context, the excerpt above may appear to display a much greater sense of pessimism than what is present in the book itself. It is clear upon reading all of Genome that Ridley’s target is not science, which he calls “a hungry furnace that must be fed logs from the forests of ignorance that surround us”, but irresponsible scientific reporting that resorts to sensational teleology. One key battleground is the debate over genetic determinism, which Ridley depicts as no more or less constricting on our free will than social/environmental determinism. Indeed, Ridley takes a broadly positive view of lines of inquiry like the search for genetic predispositions to homosexuality. If there is a genetic basis for characteristics like homosexuality or social introversion, he argues, it is all the better for our ability to accept those traits and live with them as best as we can.

Even in the case of eugenics, Ridley adheres to the same view that Richard Feynman had of the atomic bomb: that science, in and of itself, is ethically neutral; and that the ethics of its deployment is a political question. Ridley’s policy recommendations are staunchly libertarian. “Many modern accounts of the history of eugenics present it as an example of the dangers of letting science, genetics especially, out of control,” he writes. “It is much more an example of the danger of letting government out of control.” Just as it is unethical to sterilize the mentally disadvantaged through the coercion of doctors, peers, or the state, it is equally unacceptable to prohibit parents that would consider aborting a Down-syndrome child from seeking prenatal genetic screening. One intriguing example that Ridley cites as an example of beneficial voluntary eugenics is the Committee for the Prevention of Jewish Genetic Disease’s use of blood samples in advising matchmakers on arranged marriages, a procedure that has virtually eliminated cystic fibrosis from the American Jewish population.

Needless to say, this is a complicated position to take, one that lies a hair’s breadth away from a destructive aversion to medical intervention on the whole. Ridley admits that the moral responsibility of rich countries scales with their access to medical technology: “Because something can be done, so something must be done.” So on one hand, we need to accept the inherently amorphous diversity of human genomes lest we fall into the normative trappings of negative eugenics; but on the other, we must distinguish the acceptance of “normal” conditions from diseases that we have a moral responsibility to contain and, if possible, eradicate. It is admittedly difficult not to think of a Down-syndrome child as “abnormal” on account of their extra chromosome 21. The fine line between the acceptance of diversity and the acknowledgment of error is not unlike the dichotomy in linguistics between the extremities of “everything is correct” and “nothing is relevant”. As is the case with genetic and social determinism, or determinism and free will, the dichotomy is false.

For better or for worse, Genome is a product of a narrow window in history. While its lessons remain pertinent, its publication in 1999 confines it to examples like mad cows and cloned sheep. (My paperback edition contains a few hastily inserted nods to the completion of the Human Genome Project’s rough draft in June 2000, but that is as far as it goes.) Although there is an undeniable premium on being current when it comes to popular presentations of bleeding-edge science, one can’t escape the sentiment that a book like this would benefit from the distance offered by the passage of time. We are still talking about genetically modified foods and designer babies today, but now there is a firmer foundation of public policy and opinion to assess, not to mention a more complete picture of “the human genome” for us to put into perspective. Genome‘s lasting relevance may instead lie in Ridley’s efforts to reshape common assertions about cause and effect, and inform us that the extensive influence of the data stream behind our bodily design is anathema to neither our liberty nor our personhood.

Previous:
Next:

submit to reddit

3 rejoinders to “Wednesday Book Club: Genome

  1. Daniel Kaszor

    Apologies, this isn’t directly related to the book at hand, but to the book club in general.

    I think you need to read Twilight. In fact, I’m sure of it. It’s the kind of book you could dust off in a day, and it’s the kind of writing that would make you pine for Dan Brown, but you need to read it.

    Why?

    Because someone needs to write a definitive statement on why it’s fundamentally insulting to J.K. Rowling that Stephanie Meyers keeps getting compared to her.

    Saturday, 6 December 2008 at 2:56pm

  2. It’s very funny, and timely, that you mention Stephenie Meyer. You are the fifth or sixth individual to independently approach me about Twilight in the past week.

    I went on a bookshop run with a friend last night. She had been bewildered, for months, at how rapidly this Twilight phenomenon has taken off. Then she started reading it on Wednesday, and found herself burning through a book a night, and returning to Chapters the next day to pick up the next volume. I flipped through the first few pages, and I’ll probably borrow the whole thing soon enough.

    So let’s just say it’s in the queue.

    Saturday, 6 December 2008 at 3:15pm

Say something interesting: