One of the earliest scientific speculations about the origin of life was Alexander Oparin’s proposal in 1924 that life began as jelly-like blobs he called coacervates. Oparin knew that the unit of life was the cell, but it had not yet been established that cells had membranous boundaries,  so coacervates were thought to be reasonable experimental models of the “protoplasm” that seemed to compose all cells.  Oparin also discussed conditions on the early Earth as part of the story, setting the stage for what would later become astrobiology.

How did life begin, anyway?

     I am a research professor at the University of California, Santa Cruz, and over the past 30 years my students and I have been working to understand how cellular life arose. The unit of all life today is the cell, a molecular system of functional polymers (proteins and nucleic acids) that is bounded by a membrane composed of lipid.