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...information can [and does] travel from the environment to the organism and regulate gene expression. Genes do not determine the properties of the organism; they contribute to them. They are not the origin of organic characteristics, but they are involved in their realization. (p. 133)So people don't understand genes. No big surprise there. Morange shows that this is the case on two fronts, however. First, the media (and some scientists) have put forward that notion that there are genes for _____. Morange dispels this notion by showing that "our genes do not code for our behavior or our thoughts, but without genes these behaviors and thoughts would not exist." (p. 163) You may ask, "what's the difference?" and although the difference is subtle, it is important. It means that a gene isn't solely responsible, nor can manipulating a gene necessarily fix a problem or provide a wanted characteristic. The second misunderstanding is that we (and this includes scientists) don't understand which genes can possibly do what, how they work together or as backups, and how environment can alter gene expression. Despite having the genome mapped, our ignorance still reigns supreme.
With the above in mind you can imagine that this isn't as enlightening a book as one might hope. It is always more stimulating to read about what we know (and how) rather than hear that we really don't know as much as it appears. In other words, the title is not a suggestion that Morange understands genes and is going to provide that knowledge to the reader. He does provide his knowledge, but it is the disappointing fact that understanding genes is difficult, if not impossible.
Here in Morange's own words is the problem:
...we should abandon the naive idea of a simple one-mutation, one-disease relation. Different mutations, different pathogenic pathways, can lead to the same symptoms. And conversely, the same mutation can lead to two different pathological states. How is this possible? Do other genes affect the final result? Certainly. Does the environment play a role during development? Perhaps. ...genes simply orient the organism to one of a number of possible pathways. Genes act more like railroad switches [with many more switches still to come] than like the operator of a four-wheel drive vehicle who can go where he or she wants. (p. 52-53)Morange doesn't focus the entire book on the above, although it is the point woven throughout and the main reason the book is of any value. The other topics (like history, eugenics, etc.) can be found in more thorough and readable accounts elsewhere. He also touches on the search for genes that will keep you from aging and concludes with the depressing remark that "the youth gene, or rather the antiaging gene, is a mirage." (p. 119)
So just remember the following the next time you see (or read) Jurassic Park:
We can read back from the phenotype to the gene, following the causal chain that explains the character by the properties of the gene and its product. This causal chain is perfect, and each of its links can be precisely described. But if, on the other hand, we start from the gene and try to predict its effects, the diffraction of the causal chain at each increase in the level of organization makes it difficult to predict anything at all. (p. 161)
from the publisher:
At a time when the complete human genome has been sequenced and when seemingly every week feature news stories describe genes that may be responsible for personality, intelligence, even happiness, Michel Morange gives us a book that demystifies the power of modern genetics. The Misunderstood Gene takes us on an easily comprehensible tour of the most recent findings in molecular biology to show us how--and if--genes contribute to biological processes and complex human behaviors.
As Morange explains, if molecular biologists had to designate one category of molecules as essential to life, it would be proteins and their multiple functions, not DNA and genes. Genes are the centerpiece of modern biology because they can be modified. But they are only the memory that life invented so that proteins could be efficiently reproduced. Morange shows us that there is far more richness and meaning in the structure and interactions of proteins than in all the theoretical speculations on the role of genes.
The Misunderstood Gene makes it clear that we do not have to choose between rigid genetic determinism and fearful rejection of any specific role for genes in development or behavior. Both are true, but at different levels of organization. Morange agrees with those who say "we are not in our genes." But he also wants us to understand that we are not without our genes, either. We are going to have to make do with them, and this book will show us how.
Michel Morange is Professor of Biology and Director of the Center for the Study of the History of Science at the Ecole Normale Supérieure, Paris. He is the author of A History of Molecular Biology.
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