A Crack in Creation – Gene Editing and the Unthinkable Power to Control Evolution
by Jennifer Doudna and Samuel Sternberg
Review by Dave Gamrath
In A Crack in Creation – Gene Editing and the Unthinkable Power to Control Evolution, scientists Jennifer Doudna and Samuel Sternberg describe stunning advancements in biochemistry, the wide array of benefits that these advancements may bring, as well as the risks they pose to our society and planet.
Book Review:
In the first half of the book, the authors “dumb down” the complex science behind their work in attempt to make it understandable to the average reader. With no background in biochemistry, I was at times confused by their story, but still found it fascinating. Included were explanations of the genome, DNA, RNA, proteins and additional elements of the chemical makeup of living things. After explaining basic chemistry, the authors describe how changes happen in nature through random mutation and natural selection. They then described the history of science in this area, which led to scientific gene manipulation, or gene editing.
Next, they review the latest gene editing technology, known as CRISPR. CRISPR is an immune defense within bacteria in which RNA plays a starring role, and stands for “clustered regularly interspaced short palindromic repeats.” Doudna explains how there are “ten million trillion trillion” phages on earth. Phages are viruses that attack and kill bacteria. Bacteria have developed defense mechanisms to fight off phages. In one of these mechanisms, the bacteria steal snippets of an attacking phages’ DNA during the infection, and use this to mount a future immune response, designed to target and destroy the phage. This involves the bacteria’s RNA working with proteins to cut up the DNA of the virus. Doudna describes this as “a virus-seeking missile that can strike quickly and with incredible precision.” It’s an amazing defense mechanism evolved over the eons.
Doudna runs a lab at Berkley where her team studied CRISPR and determined how to use it as a highly effective genetic engineering tool. With CRISPR, the genome – an organism’s entire DNA content, including its genes – is now almost as easy to edit as a simple piece of text, bringing us on the cusp of a new age of genetic engineering. CRISPR enables scientists to find and fix single incorrect letters of DNA out of the 3.2 billion letters that make up the human genome. It is a way of reversing the effects of genetic disease by rationally and deliberately correcting misspellings in the genome. As long as they know the genetic code for a particular trait, scientists can use CRISPR to insert, edit, or delete a gene in virtually any living plant or animals’ genome. Gene editing holds the promise of life-changing treatments, lifesaving cures, and may also be able to prevent certain diseases in future humans. Basically, Doudna claims that scientists can now rewrite the “code of life”.
Doudna states that CRISPR could help cure many diseases, including sickle cell disease, cystic fibrosis, muscular dystrophy, malaria, cancer, Parkinsons and HIV/AIDS. CRISPR could help plants withstand impact of climate change. CRISPR could create “ultra-muscular” animals, higher yielding crops, healthier livestock; disease resistant and more nutritious food. CRISPR can help make agriculture more sustainable, productive and humane. The potential benefits are enormous. Amazingly, CRISPR is low cost and easy to use.
CRISPR can be injected into any species’ germ cells (eggs and sperm) or embryos, causing genetic changes that will be copied into all cells and forever transmitted to future offspring. Thus, someday CRISPR could be used to change the human genome in ways that are inheritable, altering the composition of humankind, directing the evolution of our species. Clearly this is a slippery slope.
Doudna asks many critical questions. How do we weigh costs and benefits of tampering with our own genetic code? How do we prevent CRISPR from being abused, with unintentional or calamitous consequences? Will people embrace gene-edited crops? Will “bad guys” develop “gene bombs” that can be militarized and weaponized to target the human microbiome or major food sources? Is using CRISPR admirable, deplorable or something in between?
Doudna has organized multiple forums for these issues to be discussed, looking for consensus on a best path forward. Her panels have asked that scientists refrain from attempting to make heritable changes to the human genome, yet already some scientists have. Doudna is concerned about two concrete hazards: first, reckless experiments that prematurely implement CRISPR without proper oversight or risk consideration, and second, CRISPR used nefariously, since it’s so cheap. Somewhat ironically, Doudna has cofounded multiple companies to make money off CRISPR. Where will the drive for profit lead? Is Frankenstein around the corner?
Doudna implores that we must keep an open mind. She states that once a game-changing technology is released in the world, you can’t contain it. She believes that germline editing will eventually be safe enough to use outside of the laboratory, in a clinic. That’s the big jump. She expects some will try to create human enhancements with CRISPR, but believes that a new movement of eugenics will not happen. Doudna claims that if America doesn’t lead on this, another country will. Finally, she stresses the need of open lines of communication between science and the populace is greater than ever.
Some view any form of genetic manipulation as horrible; others see the genome simply as software that can be fixed and improved. The US intelligence community has described genome editing as one of the six weapons of mass destruction and proliferation that nation-states might try to develop, at great risk to Americans. Currently, America is split on whether to use germline editing to reduce the risk of disease. I’m torn as well. But given that our culture has refused to take meaningful steps to mitigate climate change or overpopulation, within a couple decades we might not have better, lower-risk options as we adapt to a very hot and crowded world.
Reviewer Opinion:
Although technically difficult reading at times, understanding this technology and its impact is important.
Reviewer Rating of Book:
Give it a shot.