This book is the story of the birth, growth, and future of one of the most powerful and dangerous ideas in the history of science: the “gene,” the fundamental unit of heredity, and the basic unit of all biological information.
When you read good books, you start immersing yourself into the world of its words. Everytime you open its pages a parallel universe emerges for you transgress. And when the book is really good, you leave a different person. I used to feel humbled when I read books about space but I was blind to the magic that is much closer. Humbled is too weak a word to describe how I feel about the complexity within the molecular world after reading this book. Insignificant perhaps. But paradoxically all this complexity exists to define me.
Our bodies consist of billions upon billions of cells. Within each single cell is the same immutable code, handed down to it at its birth, to create an entire human from scratch. The same code also prescribes the daily functioning of the cell, its replication, and its descruction. It contains within itself the holy hindu trinity - the creator, the maintainer, and the destroyer. But unlike the mythical gods, this code is purely chemical. Made entirely of carbon, hydrogen, oxygen, and trace amounts of other elements, this code doesn’t act with purpose or intention but blindly follows the laws of nature. The blind watchmaker is not one but infinitely many, recursive. Watchmakers made of watchmakers.
A universe exists on the molecular level which is as complex, or even more complex, than the human society. To me this complexity is overwhelming, even disturbing. As I read this book, I could not but look at my own self and wonder at the miracles that are constantly happening at every single instance in every single cell of my body. Without any higher intelligence coordinating this dance, a single instruction manual, the DNA, is sent to every single cell and through that one set of instructions decades upon decades of life emerges. If we think about humanity and organic life as a whole, then that instruction manual is responsible for millions if not billions of years of life on earth. Every single moment, from birth to death, of every single living organism on this planet, pieces of DNA are being unfurled, RNA is being transcribed, proteins being created by protiens, all because it can.
We did not reach here because of a plan but because of errors in transcription. An error learned to copy itself and never stopped doing it. We live because can. We are the products of tautology. We mutate by chance and we pass on our mutations to the next generations. The mutations accumulate and a billion years later the mutant is able to recognize itself. It is now unbelievable that we, with our limited mental capacities, are able to discover these truths. We have found patterns and similarities and organizing principles through all this chaos. We started out from Mendel’s peas and Darwin’s voyages and will soon be able to rewrite our own selves, recreate ourselves in our own vision.
Siddhartha Mukherjee’s book brilliantly interleaves these two stories seamlessly - the story of the code and the story of the human discovery of it. He throws in it a third personal story, the story of the genetic illnesses corrupting his own genetic code. The three perspectives provide very different vantage points to observe the world of genes. Had I read this book as a kid, I would probably be doing biology instead of math today.