The Amino Acid Set Was Fine-Tuned for Life

Organic compounds are large molecules containing carbon and having carbon-hydrogen or carbon-carbon bonds. Many organic compounds are involved in life, and life as we know it could not exist without carbon. One group of organic compounds, known as amino acids, numbers at least 500. Of those, only 20 (or, in some cases, 22) are used in plants and animals. Why and how were these amino acids selected to make living things? Amazingly, the amino acid set was fine-tuned for life.

There are three possibilities for how they could have been “selected.” The selection could have been due to chance, with no intelligent agent involved. It could have been because of necessity, meaning that some kind of law could allow only those amino acids to be selected. The third possibility is selection by an intelligent agent with a purpose. Did this apparent choice happen because of mere chance or because of laws that required no other choice? No known laws required this selection, and chance seems questionable since the choice appears to be perfect.

With many alternatives, why this 20? Would any 20 out of the 500 work just as well? The answer is “No,” according to a research paper published in the journal Astrobiology, titled “Did Evolution Select a Nonrandom Alphabet of Amino Acids?” by Gayle K. Philip and Stephen J. Freeland. They wrote, “Random chance would be highly unlikely to represent the chemical space of possible amino acids with such breadth and evenness in charge, size, and hydrophobicity (properties that define what protein structures and functions can be built).” In other words, these 20 amino acids represent the best choice. You can say that the amino acid set was fine-tuned for life.

We have often talked about the cosmic creation event (“big bang”), the laws of physics, the physical constants, and the fundamental forces of nature as having been fine-tuned for life. It appears that the amino acid set was fine-tuned for life. The amino acids that make up the proteins in our bodies seem to be optimally selected. They must have been selected by an agent with the wisdom and power to design a complex, finely tuned, information-rich system, which we call life. We suggest that the agent is the God of the Bible. Tomorrow, we will examine more fine-tuning within our DNA.

— Roland Earnst © 2026

References: scienceandculture.com