The Gene- An intimate history

The Gene by Siddhartha Mukherjee is an elegant, engaging, and powerful piece of science writing. He is a genius in locating the emotional truth and engaging story buried in biological & chemical abstractions. The book is filled with accessible and entertaining account of a scientific revolutions. It is the story of most powerful and dangerous ideas in the history of science: the “gene”, the fundamental unit of heredity, and basic unit of all biological information. The story starts with Mendel (1856) and his idea of “unit of heredity”, intersects with Darwin’s theory of evolution and collides with the horrors of Nazi eugenics in the 1940s. The concept of gene transformed the post-war biology.

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Matter, information, and biology are inherently hierarchically organised : understanding that smallest part is crucial to understanding the whole. When poet Wallace Stevens writes, ”in the sum of the parts, there are only the parts”, he is referring to the deep structural mystery that runs through language: you can only decipher the meaning of a sentence by deciphering every individual word- yet a sentence carries more meaning than any of the individual words. And so it is with genes .An organism is much more than its genes, of course but to understand an organism, you must first understand its genes .It is impossible to understand organismal and cellular biology or evolution- or human pathology, behaviour, temperament, illness, race and identity or fate -without first reckoning with the concept of the gene.

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The entire set of genetic instructions carried by an organism is termed as a genome (think of the genome as the encyclopaedia of all genes, with footnotes, annotations, instructions, and references ). The human genome contains about between 21 and 23,000 genes that provide the master instructions to build, repair, and maintain humans. Over the last two decades, genetic technologies have advanced so rapidly that we can decipher how several of these genes operate in ?time and space to enable these complex functions . And we can, on occasion, deliberately alter some of these genes to change their functions, thereby resulting in altered human states, altered physiologies, and changed beings.

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This transition-from explanation to manipulation- is precisely what makes the field of genetics resonate far beyond the realms of science. It is one thing to try to understand how genes influence human identity or sexuality or temperament .It is quite another thing to imagine altering identity or sexuality or behaviour by altering genes. The former thought might preoccupy professors in departments of psychology, and their colleagues in the neighbouring departments of neuroscience. The latter thought, inflicted with both promise and peril, should concern us all.

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In the early decades of the 21st century, we are learning to speak yet another language of cause and effect, and constructing a new epidemiology of self: we are beginning to describe illness, identity, affinity, temperament, preferences- and, ultimately, fate and choice- in terms of genes and genomes. This is not to make the absurd claim that genes are the only lenses through which fundamental aspects of our nature and destiny can be viewed. But it is to propose and to give serious consideration to one of the most provocative ideas about our history and future: that the influence of genes on our lives and beings is richer, deeper, and more unnerving then we had imagined. This idea becomes even more provocative and destabilising as we learn to interpret, alter, and manipulate the genome intentionally, thereby acquiring the ability to alter future fates and choices.