Final answer:
Biological evolution fundamentally relies on the molecule DNA, which serves as the mechanism of inheritance. The debate of which organic molecule, DNA or proteins, came first is complex, but both are essential to living organisms. Molecular evidence through DNA and amino acid sequence comparisons supports evolutionary theories.
Step-by-step explanation:
Biological Evolution and Its Molecular Basis
Biological evolution ultimately depends on the molecule DNA or sometimes RNA. These nucleic acids serve as a mechanism of inheritance, capturing and passing down genetic information through generations. Once such a system of heredity was established, natural selection could act on these entities, leading to an increase in the frequency of those that could reproduce more effectively.
The question of which organic molecule came first, DNA or proteins, is akin to the 'chicken or the egg' conundrum. Both DNA and proteins are dependent on each other for synthesis, which leads scientists to speculate if there were other organic molecules that evolved first. Nonetheless, DNA and RNA's role in evolution is clear as they are the primary molecules that hold the genetic code, while proteins play a critical role in expressing genetic information and catalyzing important biochemical reactions.
Molecular evidence further supports the theory of evolution. Studies have shown that comparisons of DNA and amino acid sequences across different species provide insights into their evolutionary relationships, with molecular clocks being a tool to estimate the time frame for these divergences. Such evidence underscores the significance of molecular biology in understanding evolutionary processes.