The idea that living things can come from nonliving sources is called abiogenesis or spontaneous generation. This concept was proposed before the discovery of cells and microorganisms, when people believed that living organisms could arise spontaneously from decaying matter or other nonliving materials. However, this idea was later disproven with the experiments conducted by Louis Pasteur in the 19th century. Pasteur's experiments demonstrated that living organisms only arise from preexisting living organisms, a concept known as biogenesis. The theory of biogenesis is widely accepted in modern biology.
