Summary
This chapter covers the origin of life and early evolution, focusing on how simple organic compounds emerged on early Earth through various natural processes. It outlines critical experiments like the Miller–Urey experiment and explores multiple hypotheses including the RNA world and endosymbiont hypotheses, which trace the evolutionary transition from simple molecules to the complex cellular structures found in modern prokaryotic and eukaryotic cells. Fossil evidence, such as stromatolites, supports these concepts and highlights the monumental role of changing environmental conditions, especially the rise in atmospheric oxygen, in shaping life’s diversity.