On Life

Around the 1950s, biologists began to leverage the power of the computer to understand evolution by generating simulations. The mechanisms of evolution are fairly algorithmic and ordered, given a population of n organisms, ranked in descending order by their fitness, remove the u organisms that are too low on the list to be fit enough to survive and randomly breed the top n-u organisms, ensuring that mutations can occur during the breeding process. The most important component to this algorithm is the fitness function, the environment manages to do it very well without having to put anything into quantitative terms, but how do we reduce the complex principle of natural selection to pure math? Often times, it involves understanding predator-prey relationships and creating functions that relate the fitness of one organism and that of another. There is no all-encompassing equation to how natural selection works. Despite this limitation, the simulations were overwhelmingly successful in helping biologists examine evolution without being hindered by its excessive time requirement. These simulations not only helped bring about the interdisciplinary field of computational biology, but legitimized genetic algorithms (algorithms that use the mechanisms of natural selection to problem solve) in real world applications.

The success of a biological simulation on an electronic machine also points to something else, that perhaps our biology is binary at its most basic level. The presence or absence of a transcription factor determines whether or not RNA polymerase can bind to DNA and begin transcription. The presence or absence of glucagon determines whether or not the liver will release store glycogen to glucose. The presence or absence of the gastrin hormone on the inter-membrane receptors of parietal cells in the stomach determines whether or not gastric acid is released to aid in digestion. All of these events rely on binary conditions, zeros or ones, to trigger actions in the human body. To the programmers in the room, our bodies are a giant collection of if-then statements, more complex than anything a human can imagine. Similarly to a machine, the molecules that make up our body are as unaware of their larger purpose as the the transistors that make up a computer processor. Both the computer and the body are organized into modular systems based on abstractions. You cannot understand the human body by looking at one cell in one organ, the purpose emerges at a larger level of interconnectedness.

There are differences though. As a (budding) computer scientists, I am often bothered to learn that the body relies more of accidental collisions and chance than it does on perfect order or logic. A strand of mRNA released into the cytoplasm of a cell will soon begin to suffer from the hydrolytic enzymes that float ominously around the cytosol looking for something to destroy. What has the body done to combat this erroneous attack on its own? A compound attached to the mRNA that breaks down hydrolytic enzymes? Compounds that guard the mRNA as it floats in the cytosol? Any other seemingly ordered and logical solution? No, instead a sequence of adenine nucleotides of variable length is attached to the end of the mRNA strand. These nucleotides are sacrificed to the hydrolytic enzyme, the length of this sequence is directly proportional to how much of the protein that the mRNA strand codes for is produced. Life does not get to pick how it functions, if a solution emerges that works and is efficient enough in terms of energy expenditure, it will be used. Life’s not choosy.

The abstractions and redundancies that allow our body to function so efficiently, can also destroy it. Proto-oncogenes regulate cell growth and differentiation in cells, as long as they are working properly. When they are not working properly, they become oncogenes that can cause cancer. Harmful mutations in DNA are especially vicious because they attack the core program of a biological system. Harmful mutations in proto-oncogenes not only attack the core program of the biological system, they alter the way it functions on a rudimentary level. Cells go rouge and divide without obeying signals to stop and perform their function. These rogue cells can take over an entire organ and its neighbors, disturbing what little harmony was present in the body. Cancer is a brutal remainder that despite everything that it has brought about, life is not perfect and can often fall victim to itself. It hopefully relies on the fact that if something does go wrong, it won’t be too bad.

Life is strange fusion of chaos and order. Life is the understanding that while entropy rules over our universe, it doesn’t necessarily rule over what life can do. Life shares the complexities of a computer, but opts out on the order. Life leverages the ordinary to do the extraordinary. Life is what atoms do when left untended to.

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