The Gene

The Gene in one diagram, from the book

Somewhere in the midst of late 2019, in the foggy chill of a typical Delhi winter, in the last glorious months of the BC (Before COVID) era, I picked up The Gene, eager to continue my Siddhartha Mukherjee reading spree, a list that included his [spellbinding] debut book and a host of articles, mostly in The New Yorker. The winter break quickly drew to a close and, 300 pages in, I packed my bags for the journey back to New York with no inkling of the depressing time to come. I forgot to pack the book – my travel read. Months later, COVID struck, and we were all stranded.

The book was placed on a shelf, soon buried under a frenzy of new book purchases bought by a family in urgent need of entertainment during successive lockdowns. A book on genes, on heredity, variation and mutation, environment and chance, and on the future of a species, incited queasiness when the species in question was under siege. It was lost.

2022 brought me back to Delhi. We are still besieged by the pandemic – its contours have changed as have our defenses. We’ve barely learnt to live with it, carrying scars from the trauma unwillingly collected through 2 back-breaking years.

“Even the environment signals its presence through the genome,” writes Mukherjee in a chapter on epigenetics. Epigenetics studies cellular memory. Every individual’s genome collects memories over time triggered by experience, environment, and chance. These memories occur not as mutations, that is, as alterations in the sequence of DNA nucleotides, but in the chemical structure of the DNA, through markers and tags.

This is a provocative thought. I wonder if COVID has made its presence felt in the genome. The world has endured years of recurring stress and existential anxiety, not to mention actual infections. The developing world has had it worse (as usual) – 2020 was the year of shock and lockdowns in India. Carnage was unleashed in 2021.

Have we been tossed into a massive experiment with no control group?

That the environment may influence gene expression is disquieting. Can nurture influence nature? Can cellular memories be modified? Can they be erased? Mukherjee is quick to caution the reader. Epigenetic memories do not conveniently lace the genome with markers for every important cellular event. Nor do these markers act in a way that can be conveniently interpreted. “Most epigenetic memories are the consequence of ancient evolutionary pathways…” In other words, you cannot cut the tails of mice over successive generations hoping a tail-less mouse will emerge. Really – scientists have tried.

The tension between scientists’ attempts to learn and control the discrete determinants of human information and the danger of tampering horribly, possibly irreversibly, with the human organism runs through The Gene. Jennifer Doudna and Emmanuelle Charpentier’s recent Nobel is a terrific example of the speed at which we’re moving. Doudna-Charpentier found ways to control bacterial switchblades that can precisely target genes. This technology is only a decade old, and it has already promised the ability to modify our own genome. Are we capable of treating this awesome power with respect?

What makes Siddhartha Mukherjee’s book different from many other excellent books on genetic research is his openness to discuss these societal implications of research – its past, present, and future. Consider the past, a time littered with the evil of eugenics, of deadly research designs, of treating homosexuality as a Freudian neurosis. But also, a time when we learnt the genetic determinants of heritable diseases and developed new techniques of providing insulin and other proteins to people suffering from chronic problems. Mukherjee’s book is as much about the former missteps as about the science.

Now, consider the future – a world where we could screen embryos for their propensities beyond disease/disorder and about their personalities. Or even more – a world where people could choose the attributes they wanted in their babies. Mukherjee does not relegate scientific facts on these sensitive topics to the margin; quite the contrary. But he also gives adequate space to the larger public debate around what counts as “normal” and whether extreme individual choice to pre-select/design embryos is acceptable. (It must be admitted though that his enthusiasm often misses the gravity of these ethical concerns.)

The Gene is a remarkable book dripping with facts and a narrative that refuses to let go of your attention. We witness legendary characters – Mendel, Darwin, Franklin, Sanger – who changed our understanding of humans as a species. We see the debates that animated scientific circles, and we learn that abstruse discussions can have terrible consequences. Regulation enters the pure scientific enterprise and the reader roots for it!

I write this review in Delhi. When I returned earlier this year, during a rather cold and dismal winter, I brought back 25 kg of books with me – those that were read in New York and deserved to join the ranks of my home books.

As I was desperately squeezing them into our overflowing shelves, I found The Gene, deeply ensconced, hidden away, calmly holding a wealth of knowledge, not caring if a prying eye would discover it.

There is no better metaphor for the actual gene, I think, except this natural book is infinitely deeper. And dangerous.