Unit 7 · 7.12 — Origins of Life on Earth [cite: 28, 44]

Everything to learn here

• Concept: Accepted scientific models logically suggest life originated from inorganic precursors slowly synthesizing organic monomers, a process strongly supported by the landmark Miller-Urey experiment [cite: 44, 45].
• Vocabulary: RNA World Hypothesis — the widely accepted origin model proposing that very early life utilized RNA both as a genetic information repository and as a catalytic enzyme long before the complex evolution of DNA and proteins [cite: 13, 44].
• Concept: Scientific evidence suggests Earth formed 4.6 billion years ago, with the first life appearing roughly 3.5 billion years ago.
• Concept: Geological evidence and fossil dating provide a plausible timeframe for when life first originated on a cooling Earth.
• Concept: The RNA world hypothesis posits that RNA served as the original genetic material and catalyst before DNA and proteins.

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