1. The (supposed) origin or evolution of living organisms from lifeless matter without the action of living parents; spontaneous generation (introduced by Professor Thomas H. Huxley when addressing the British Association at Liverpool, September, 1870): Our professor explained the theory of abiogenesis when we were learning about the evolution of species.
2. The now discredited theory that living organisms can be spontaneously generated directly from nonliving matter: There are conflicts as to whether abiogenesis has any validity.
3. Spontaneous generation; the concept that life can simply arise spontaneously from nonliving matter by natural processes without the intervention of supernatural powers: There have been many throughout history who have strived to disprove the theory of abiogenesis.