Final answer:
The RNA bases A, C, G, U were selected during the chemical evolution of life due to their ability to efficiently store and transfer genetic information, as well as perform chemical reactions necessary for life. Carbon's unique bonding properties allowed for the diverse organic molecules crucial for life's complexity. This molecular selection reflects the stability and replication efficiency needed in Earth's early conditions.
Step-by-step explanation:
The nucleotides A, C, G, U in RNA are indeed chosen for good chemistry reasons. The evolution of life on Earth favored these molecules because of their ability to efficiently store genetic information and participate in chemical reactions crucial to life. Carbon's versatility in forming stable bonds with other biogenic elements (CHNOPS) enabled a vast array of organic molecules to form, providing the raw materials necessary for life. In particular, the nitrogenous bases found in nucleotides include certain cyclic structures with carbon and nitrogen that play a key role in the pairing and information transfer processes due to their unique properties, like hydrogen bonding.
Not every C-N ring structure would support life similarly, as the biological functions require specific molecular interactions that are facilitated by these nitrogenous bases' shapes and chemical behaviors. The DNA and RNA structures that emerged as the foundation for life were likely among the most stable and capable of perpetuating themselves in the primeval conditions. The presence of amino acids and the ability to encode and replicate information were critical, and the molecular components chosen by life are a testament to the successful chemical evolution that led to modern biochemistry. The transformative step from simple organic molecules to the complex molecular dance of DNA and protein synthesis is central to our understanding of life's origins.