This must be by far the most captivating book on the history of a subject/field. Siddhartha Mukherjee truly has mastered the art of writing history in a very captivating way. The book is highly informative, very very research oriented, and seldom makes it monotonous.
There are a ton of plus points with this book, so, I'll start with the shortcomings, which are fewer. Firstly, the chapter names don't tell you what the chapter is about, so it's hard to re-read certain interesting topics without explicitly noting down. The quotes at the beginning of the chapter are also, while quirky, not very sensical. Secondly, in all of this, I was hoping there would be a section dedicated to savants and the genetic research on them. But there wasn't any. Same with all the computational work going on about protein folding etc. But these can be discounted easily given the amazing way the rest of the story is narrated!
Firstly, the name is very apt, both "The Gene" and the "An Intimate History" parts. It starts all the way from Pytagorean theory of the idea of Genetics (that dude is practically everywhere). Then a bit of Aristotle, medievals etc lead us to the first generation heroes of the subject - Mendel and Darwin. Their stories have been narrated in a fascinating manner teeming with trivia! Mendel's landmark presentation and its lacklustre reception, Darwin's fame, Darwin's cousin - Sir Francis Galton's dabbling with Eugenics etc are a treat to read about.
Then a second wave of heroes spring up with Bateson and his rekindling of Mendel's efforts, the work of de Vries, Lamarck, Wallace etc which culminates with the cut-throat and the most brilliant experimental geneticist Rosalind Franklin's efforts to photograph the DNA, and finally Watson and Crick's modeling of the same, giving rise to the iconic Double Helix.
The rest of the book talks about a variety of topics, like cloning, the genetic link of Haemophilia, Sickle Cell Anaemia (and even its link to Russian revolution), Schrodinger's "What is Life" essay (again, this dude is everywhere too, pun intended), it even has the mentioning of PaanDu Roga of ancient India (remember PanDu from Mahabharatha?), CRISPR (cas9), the ethics of gene therapy, the story of the discovery of Islets of Langerhans and invention of Insulin, Human Genome Project and our 20,000 odd genes, patent wars between Genentech and others involved in the invention (or discovery) or new genes and their mechanisms, Morgan's Fly Room experiments and the mind boggling emergence of flies with altered structures etc.
The book also does a great job at explaining the mechanism of how the gene works and why it's not a one way street between genotype and phenotype, but a full circle that encompasses the environment. Overall, I found this book absolutely incredible, something I'd use to get inspired about all the work it takes to create something brand new.