Life on Earth is a riot of diversity, united by the shared biochemistry of DNA and RNA. Tracing these threads back through time suggests all life descends from a Last Universal Common Ancestor (LUCA), which emerged between 4 billion and 4.5 billion years ago. How this LUCA rose from the primordial stew remains a mystery due to a lack of fossils and Earth being the only known life-bearing planet.
Scientists debate whether life began in a 'warm little pond' on the surface or in the deep ocean near volcanic vents. The primordial soup hypothesis, tested by Stanley L. Miller in 1953, showed amino acids could form from simple chemicals and energy, though they never advanced to life.
Meanwhile, deep-sea vent discoveries in 1977 revealed ecosystems powered by chemicals rather than sunlight, suggesting life may have originated in the depths, shielded from radiation. Recent research continues to support both theories, with John D. Sutherland demonstrating in 2009 how life's molecules could assemble on the surface using ultraviolet light.
Source: New York Times Top Stories · Summarized by HeadlinesBriefing