According to the American magazine Wired, the connections between the building blocks of life in the universe may be closer than previously thought, and humans and aliens may have the same genetic structure. This pattern was found in amino acids formed in meteorites, deep-sea hydrothermal vents, and simulations of early Earth conditions, and it appears to follow the basic principles of thermodynamics, suitable for the known universe.
Ralph Pudritz, an astrophysicist from McMaster University in Hamilton, Ontario, stated, "This may indicate that the structure of the first genetic code in the universe is the same." Specifically, there are 20 amino acids, which combine to form complex molecules called proteins, and proteins, in turn, can form nucleic acids to complete the simplest process of self-replication.
Through the famous 1953 Miller-Urey experiment, 10 amino acids have already been synthesized artificially. This experiment simulated the early environment of Earth and volcanic lakes. These 10 amino acids were also found in meteorites, sparking debates about the diversity of life on Earth.
Pudritz, together with McMaster University biophysicist Paul Higgins, published a paper on arXiv. However, this does not mean previous debates are over; on the contrary, it confirms that ordinary amino acids are more widespread than imagined. They only require relatively warm meteorites and a sufficient size, which is just a small beginning.
If the observed structure in an amino acid sequence is of simple acids, only a small amount of energy is needed to combine them; complex acids require more energy — this does conform to the principles of thermodynamics, meaning that the basic forms of life's origin are universal throughout the cosmos. Pudritz stated, "Thermodynamics is a fundamental law; it must apply to all phenomena in the universe. If you can find certain ranges naturally, this implies universality. It still needs testing, but it seems quite plausible."
Pudritz and Higgins arranged the types and frequencies of amino acids found in early Earth formation experiments into tables, representing related results with comparative curves of the temperatures and pressures at which acids could form. The 10 artificially synthesized amino acids from early Earth formation experiments are produced at relatively low temperatures and pressures, and their chemical structures are simpler;Additionally, more complex acids are formed relatively less and require higher temperatures and pressures, a distribution pattern that fully complies with the principles of the basic thermodynamic curve. Pudriz stated, "The amino acids that form the most also require the least energy; the fewer the amino acids formed, the more energy is required. From a thermodynamic perspective, this is entirely reasonable." The internal temperature conditions of meteorites are still unknown to humans, but some scientists believe that certain large meteorites are both warm and water-containing, roughly similar to some temperature environments on early Earth. Pudriz said, "There is a theory suggesting that these basic structures could have formed within the warm interior of sufficiently large meteorites."
Of course, this is just a hypothesis, but it explains why the ten most common amino acids in early Earth formation experiments are also the most commonly found acids in meteorites. Pudriz and Higgins speculate that, if combined with other less common acids using an early genetic code, these ten common amino acids would be sufficient to generate the earliest self-replicating molecules. This process is referred to as 'progressive evolution,' reaching its peak in the genetic evolution 3.6 billion years ago, with all complex life originating from a common ancestor. If the interactions among these ten amino acids are simulated, it can indeed produce molecules capable of self-replication, thus potentially forming a familiar type of genetic code. It could indeed be universal, as any genetic code would require amino acids.