The Code Breaker by Walter Isaacson


Having admired his book about Steve Jobs, I knew I would appreciate Isaacson’s book about Jennifer Doudna. He does a good job of explaining the how scientists learned about RNA and CRISPR, but it’s still a big mystery to me. I now recognize a lot more words on the topic, but wow, it remains an alien world to me.

First, CRISPR:  it is a relatively quick and easy way to edit the DNA in a cell. The letters stand for Clustered Regularly Interspersed Short Palindromic Repeats. Scientists noticed that RNA turns up in certain formations with the characteristics described by those words; for me the amazing word in that string is “palindromic.” What? They read the same either way?? So many questions.

One thing that was revelatory to me was learning that bacteria and viruses have been at war forever. So it was useful in making these discoveries to observe how the bacteria in yogurt evolve to fight off viruses that threaten it. A company called Danisco, a dairy food company, had records showing that evolution involving RNA and a protein called cas used to snip the DNA in the virus to protect the yogurt. Yogurt uses CRISPR. How can that be?

Much of this book describes the various scientists and how they cooperate, and even more, how they compete. The story involves fights over patents which makes for a slow-moving drama. In the end Jennifer Doudna and her sometime-collaborator Emmanuelle Charpentier won the Nobel Prize in 2020. The cooperation level changed significantly when the pandemic came our way.

The alarming and exciting part of the book considers the gene editing ability of CRISPR. With this technology theoretically we can edit genes so that children are born without certain genetic material that causes cancer, sickle cell anemia, and other diseases. It also means humans could choose certain physical traits for their offspring:  athletic ability, blue eyes, blond hair. Isaacson and the scientists he spoke with recognized some of the problematic aspects of this, but the take in this book was too ready to consider modifying the genetic code for humans in perpetuity. Gene editing can occur which affects only the individual, while some, called germline gene therapy, would change the DNA for all offspring of the individual.

My reaction is influenced by Lulu Miller’s book Why Fish Don’t Exist. She wrote about the eugenics movement that was so widely accepted in the late 19th and early 20th centuries when it was thought that certain traits such as criminality and immorality could be bred out of the population. While this seems unthinkable to us now, a Supreme Court decision allowed the forced sterilization of a Virginia woman in 1927. When Isaacson and others speak of changing the genetic code to reduce the chance of an offspring having schizophrenia, I believe that is as fraught as eliminating “criminality.” The radically different views of matters such as gender in this country is an indication that allowing the use of powerful tools to “fix” something is a worrisome prospect. Who gets to define what is “desirable”?

Lulu recounts Darwin’s view that for a species to be strong, it must be varied; we do not know what traits will be most useful in the future. She says that according to Darwin, “Homogeneity is a death sentence. To rid a species of its mutants and outliers is to make that species dangerously vulnerable to the elements. In nearly every chapter of Origin, Darwin hails the power of ‘Variation.'”

Even editing genes to eliminate an awful disease such as sickle cell anemia has its perilous aspects. The gene that causes that disease also protects against malaria. While in that case humanity might choose to make that trade, the problem of knowing what all the implications are is an important one.

I found Isaacson’s description of the societal implications of gene editing to lack the depth that consideration of using such a radical tool requires.

Walter Isaacson, The Code Breaker, Simon and Schuster, 2021, 536 pages (I listened to the audiobook). Available at the public library.

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