The Demons in the machine is a challenging book to read, as it adopts an unusual view of biology through the lens of information theory. From a biology background knowing the minimum about Shanon’s H, this book really shift my thinking about all the living processes from a descriptive manner to a more reductionist view, capturing the essence of the biological system to better understand how it is “wired” together.
Like the “Radio analogy” mentioned in the book, to best understand how these complex systems work, we shall establish rules to build useful models, rather than dissect every components into the finest details. Nowadays biology give us insights into all the components of life, but we still don’t fully understand how things come together serving a definitive function and behave over time and the changing environment. This is really a wake up call to us researchers to reflect on how to tackle, not avoiding, the complexity in biology.
The key idea of the book is that the organism is a superb information organiser, from the basic tasks i.e. metabolism to the more fancy functionalities like consciousness. The book shows that nature’s complexity results from optimizing the flow of entropy/information/energy to thrive in the environment.
One of the areas that the book spent most coverage on is about the genetic code. It posits that life is the most powerful replication machine with the genetic code both serve as an instruction manual of how to replication as well as an material that needed to be copy. Such dual role and when to serve in one role or another is so unique and groundbreaking.
On top of seeing the genetic code as a set of rules, these rules response to the environments and change accordingly, as demonstrated in epigenetic inheritance and evolution. The genetic code is intrinsically equipped with degrees of evolvability, so as to provide resilience to the biological system!
Davies also discribed a few less famous examples to show that biological systems respond to and acquire a lot of information that we barely notice: gravitational attraction, magnetic field, and chemical signals. As we see that cells perceive the surrounding with clues that we have overlooked so far in mainstream experiments, we shall be more cautious and open about how and what we quantify and measure biological systems.
The later half of the book demonstrated how biological pathways are so intervene with quantum mechanics. In the example of photosynthesis and neural transmission, the almost-perfect efficiency to convert charges to energy is achieved through biological design that exploit quantum properties. A new thing I learnt is that our smell distinguishs odor through oscillation patterns of the chemical, another type of information.
In this book, Davies kept raising different phenomena in biology to urge us to rethink about how life manage information, and how scientists shall renew our concept to study life, as modular system with feedbacks to attain collective function. It is about how to see the bigger pictures, to understand how the system works as a whole, governed by a set of ever changing rules responsive to its surrounding. This is definitely a refreshing read!