Y

Despite the completion of the Human Genome Project 20 years ago and the discovery of the double helix turning 70 this year, our understanding of how life functions is still limited. While physicists continue to search for a Grand Unifying Theory, the life sciences have already discovered four unifying theories in the span of 100 years. These include cell theory, evolution by natural selection, universal genetics, and chemiosmosis, which explains how living organisms extract energy from their surroundings through a continuous chemical reaction. In summary, life is a result of cells using energy from their environment, constantly evolving from previous forms. This achievement in understanding life surpasses that of physicists.

Although biology follows certain laws to explain all living things on Earth, it is a messy subject and our understanding of how chemistry transitions into biology is still incomplete. These overarching concepts are powerful, but they lack specificity and the intricacies of biology lie at the molecular level, making them difficult to comprehend. As noted by physicist Philip Ball in his recent book, this was evident when a previously unknown virus emerged in 2020, causing widespread devastation and claiming millions of lives. However, while it proved fatal for some, others experienced only mild symptoms or were completely unaffected. The reason for this discrepancy remains unknown.

The title “How Life Works” is more compelling compared to the overused query of “what is life?” This question was used in a series of influential lectures and accompanying book in 1944 by Erwin Schrödinger, known for his theoretical box with a quantum cat. Since then, this question has been adopted by many in an attempt to appear profound. Personally, I find it mostly pointless and contradictory to scientific thinking. Instead of focusing on defining something, we should pay more attention to its actions. Attempting to define a living being is akin to a creationist approach, as it suggests an unchangeable ideal type. However, this goes against one of our fundamental laws: the Darwinian principle that living things are constantly evolving in both time and space.

However, this concept is ingrained in our society: a crucial energy, the essence of existence, a mysterious yet necessary characteristic that sets apart the living and the deceased. What defines life? It can be difficult to define, but we recognize it when we encounter it, to quote US Justice Potter Stewart in 1964 (though he was specifically addressing an intangible interpretation of pornography).

According to Ball, we commonly use metaphors and analogies to understand and delve into the intricacies of life, but they are not enough. For example, we are taught that cells function like machines, yet no machine we have created operates like a basic cell. We also refer to DNA as a code or blueprint, but it is neither. Similarly, the brain is often compared to a computer, even though no computer can replicate the functioning of a brain.

It’s interesting that we attempt to simplify the most complex beings in the universe – living organisms – into a single explanation. We have a desire for a satisfying story in deciphering complex systems, but evolution has been at it for 4 billion years and never had a plan to be understood by its intelligent creations. James Watson, one of the scientists who revealed the double helix structure of DNA in 1953, once claimed that his colleague Francis Crick burst into a pub in Cambridge and announced that they had uncovered the “key to life” (although Watson later admitted that he had fabricated the scene for dramatic effect in 2017). Ball points out that we don’t attempt to do this with art or other beautiful things – no reader or scholar tries to isolate and distill the “secret of Dickens”.

These simplifications and comparisons are a result of the fact that it is insufficient to just use the dismissive phrase “it’s more complicated than that” and assume that students won’t feel overwhelmed and disinterested. However, Ball questions whether the models we use in our teaching simplify things too much without acknowledging the inherent complexity, almost as if we are trying to avoid thinking about biology altogether. This brings to mind a more valuable mantra from statistician George Box: all models are flawed, but some are still beneficial.

Ball draws a clever comparison between language and genetics. He poses the question of how one goes from a simple dictionary to rich literature. The answer is similar to the process of going from words (+magic) to sentences (+magic) to chapters and books. In the same way, a living organism goes from genes (+magic) to proteins (+magic) to cells (+magic) to tissues and bodies.

The magic mentioned is not actually supernatural. It is simply the unknown or unexplainable aspects of life, which are key to understanding how life functions. The book covers the basics of genetics and how our current understanding and teaching of genes does not align with what geneticists actually know. Contrary to popular belief, there are no specific genes responsible for complex human traits or behaviors, despite the common headline “Scientists discover gene for…”. This misconception is deeply ingrained in our culture. Recent studies show that our methods of teaching genetics to children not only perpetuate this misunderstanding, but also promote a version of racial essentialism that has long been disproved by science.

The size of a ball increases from genes to proteins, cells, and networks. This process allows us to delve into the unknown wonders that bridge the gap between chemistry and biology. At the same time, we reject the harmful concept of nature versus nurture. “I cannot emphasize enough,” he declares, “that life can only function in relation to its surroundings.”

Ball is an impressive author, producing books on a wide range of topics at a pace that leaves me feeling envious and inadequate. The book is filled with well-researched information, though some details may be difficult for casual readers to digest. The inclusion of black-and-white illustrations of complex proteins may not be very enlightening. However, overall, the book serves as a necessary introduction to our unending pursuit of comprehending life. Ultimately, the question of “what is life?” does not have a practical answer. Instead, “how does life work?” should be the driving force for future biologists from birth to death.

Source: theguardian.com