How Was RNA Created?
The prevailing theory, known as the RNA world hypothesis, suggests that early RNA molecules formed spontaneously from free-floating nucleotides present in a primordial soup of molecules on early Earth. These nucleotides bonded together to create RNA strands, though these early strands were likely unstable and degraded rapidly.
According to the RNA world theory, as detailed in the RNA world article on Khan Academy and supported by research from UCL, the necessary building blocks, nucleotides, existed in abundance in Earth's early oceans. These nucleotides spontaneously assembled, forming short RNA strands. These early RNA molecules were not as stable as modern RNA but possessed the ability to self-replicate, a crucial step in the origin of life. A UCL-led team even proposed a single process for the creation of these nucleotides on early Earth.
RNA's Catalytic Abilities
Importantly, some RNA molecules possess catalytic activity, meaning they can act as enzymes. This is significant because it suggests that early RNA could have both stored genetic information and catalyzed chemical reactions, fulfilling both roles necessary for the development of life. This catalytic ability is discussed in a Reddit AskScience thread.
Challenges and Further Research
While the RNA world hypothesis provides a compelling framework, much remains unknown about the precise conditions and mechanisms that led to RNA formation. The NCBI's Molecular Biology of the Cell notes that the assembly of the first membrane-bound cells from amphipathic molecules, encompassing self-replicating RNA, is another crucial and still somewhat mysterious process in early life. Studies continue to explore the details of RNA's origins, moving us closer to understanding how life began.
