What hypothesis suggests that the earliest life forms used RNA solely for genetic material storage?

The RNA world hypothesis posits that early life forms primarily relied on RNA molecules for both genetic information storage and catalytic functions. This theory suggests that RNA came before DNA as the main genetic material. In a primordial setting, RNA could have formed spontaneously and served a dual role, facilitating the storage of genetic information and catalyzing biochemical reactions, akin to how enzymes work today. This hypothesis is significant because it provides a plausible explanation for the origin of life, emphasizing that an RNA-based system could have been stable and functional before the evolution of DNA and proteins.

In contrast, the DNA world hypothesis proposes that DNA was the first molecule to store genetic information, which contradicts the foundational role of RNA in early biochemistry as suggested by the RNA world theory. The protein world hypothesis emphasizes proteins as the initial molecular basis of life, which does not align with the necessity for a genetic material carrier in early life. The ribozyme world concept emphasizes the role of RNA enzymes, but still falls under the broader RNA world hypothesis. Thus, the RNA world hypothesis aligns with the idea that RNA was central to early life forms, serving initially as the sole genetic storage material.