biogenesis

Biogenesis is the principle that living organisms develop only from preexisting life. This concept directly refutes the older, disproven theory of spontaneous generation, which suggested that life could arise from nonliving matter. For example, spontaneous generation was once thought to explain how mice could appear from rags or maggots from decaying meat.12

The scientific understanding of life's origins has evolved significantly. Early Greek philosophers proposed that life could originate from nonliving matter, a concept later refined by Aristotle. However, experiments by scientists like Francesco Redi in the 17th century began to challenge these ideas for larger organisms. It was Louis Pasteur's conclusive experiments in the 19th century that definitively proved that microorganisms also reproduce from existing life, solidifying the principle of biogenesis.31

Abiogenesis, distinct from spontaneous generation, is the scientific hypothesis that life arose from nonliving matter over 3.5 billion years ago under specific early Earth conditions. Modern research, including the Miller-Urey experiment, explores how organic molecules could have formed from inorganic materials in a primitive atmosphere.4