A dense, but fascinating book on a puzzling subject: how does life work. The author freely admits that he doesn't have the answer, and biologists are still working on the problem. But what he does say is that the 'gene-centric' view of life, sometimes pushed to ridiculous limits (i.e., "it is not my fault, my genes made me do it"), is incorrect and won't lead us to the answers as to how life works and what makes life so different from non-life.

Starting from the smallest details, the author shows that while DNA does store the information needed to produce proteins and RNA, it is very far from being the 'blueprint of life'. The Human Genome Project, covered by the author, may have decoded the genes that make us human, but it is still far from helping us to solve the problem of how to make a human from a single cell formed from a merger of an egg and sperm.

Instead, the author shows that the interplay of DNA, proteins and RNA at the cell, tissue and higher levels are what make life work, in the broadest details (once again, scientists are still working hard at puzzling out the details). DNA may help provide the information on how to make the proteins and RNA needed for life, but it is far from being able to dictate how to make a body. Proteins and RNA regulate and coordinate among themselves, at the cell level and higher, using the instructions provided by DNA (but sometimes ignoring it) to build the cells and tissues that make up a body (human or otherwise) as it develops and interacts with its environment.

An analogy provided by the author that I found illuminating is that of the development of cities. Cities get started in different ways and in different environments. Yet their overall structure (business and civic districts, transportation networks, housing) resembles each other. City administrations (the DNA) may roughly dictate the purpose and locations of areas, but it is the 'people on the ground' (the proteins and RNA that do development) that decide what actually gets built depending on the material and environment available.

In the same way, DNA may provide instructions for creating proteins and RNA required to create cells and regulate them, but it is the cells and, at a higher level, the tissues, that determine how the body gets built, based on the environment the body finds itself it. For this reason, searches for a 'gene that does X' mostly fail because what does X is dictated at the level of the cell and tissue, not by the gene.

Throughout the book, the author shows time and again how little genes actually determine things. A recent prime example is COVID-19. Despite knowing the intimate structure of how the virus invades a cell, the huge number of possible results (from people 'just' having colds to suffering from Long COVID or other disabilities) shows that it is the body's reaction to the virus, not the DNA in our bodies, that determines how sick we can become.

Another subject the author touches on is, of course, human sexuality. And here, he shows why those that say that genes (the X and Y chromosomes) determine our sexual orientation are out of touch with reality, with the various ways bodies and cells can develop to have male or female characteristics, despite the instructions that the genes are providing that say otherwise.

An entertaining book that needs time for the information to sink it. And one that probably needs to be read sooner rather than later, but it is quite possible that some of the details in the book may prove to be wrong, as new ways to look at how life works get discovered by future developments in biology. But overall, a good overview on what modern biology has to say, for now, about how life works.