THEORY OF SPONTANEOUS GENERATION - ABIOGENESIS OR AUTOGENESIS -
- According to this theory, the existing living communities have originated from non-living organic matter without the intervention of living entities, i.e., abiogenetically.
- The various concepts regarding the origin of life due to spontaneous generation are as follow:
- Anaximander (611-547 B.C.) stated that plants and animals were formed from inorganic substances.
- Epicurus (342-271 B.C.) had the opinion that the origin of worms and other animals from the soil or decomposed faecal matters of animals due to the warmth of the solar system and air present in the atmosphere.
- Aristotle (384-322 B.C.) said that not only worms and insects but also fishes, amphibians and mice have emerged spontaneously.
- Aristotle believed hierarchial increase of complexity as shown in "Scala naturae"
- Non-living → plants → sponge → animals
- Once formed organism start reproducing themselves.
- Van Helmont (1642) was the opinion that human sweat and wheat bran when kept together in dark cupboard for 20 days can form mice.