[Biology Class Notes] on Spontaneous Generation Pdf for Exam

Spontaneous generation meaning or the spontaneous generation definition is given as the hypothetical process where the living organisms develop from nonliving matter, and also, the archaic theory that utilized this particular process to explain the origin of life. Pieces of bread and cheese are wrapped in rags and placed in a dark corner, according to the theory. For example, they were therefore thought to form mice because, after many weeks, there were mice in the rags. Several people believed in spontaneous generation because it clarified events like the appearance of maggots on decaying meat.

Description and Terminology

The term “spontaneous generation” refers to both the alleged mechanisms in which various types of life may emerge repeatedly from sources other than eggs, seeds, or parents, as well as the theoretical concepts offered in support of such a phenomenon. Crucial to this doctrine is the idea that life comes from the non-life and that no causal agent, such as a parent, is required. Abiogenesis is a term used to describe hypothetical mechanisms in which life develops from nonliving matter on a time scale of minutes, weeks, or years (for example, the presumed seasonal generation of mice and other animals from the Nile’s mud).

Such types of ideas have zero operative principles in common with the modern abiogenesis’ hypothesis, which asserts that life emerged in the planet’s early ages, over a duration of at least millions of years, and subsequently diversified, and that there is no proper evidence of any subsequent repetition of the event.

The term equivocal generation, at times called xenogenesis or heterogenesis, describes the supposed process where one form of life arises from a different and unrelated form, such as tapeworms from the bodies of their hosts.

The term “spontaneous generation” fell out of favour in the years following Louis Pasteur experiment in 1859. Bread and cheese are wrapped in rags and placed in a dark corner, according to the theory. At the same time, heterogenesis was applied to the generation of the living thing from once-living organic matter (like boiled broths). In addition, Henry Charlton Bastian coined the word archebiosis to describe life that arises from inorganic materials.

Bastian coined the word biogenesis in 1870 to refer to the formation of life from nonliving matter, because he disliked the unpredictability and randomness implied by the term “‘spontaneous’ generation.” However, soon thereafter, an English biologist named Thomas Henry Huxley has proposed the term abiogenesis to refer to the same process and has adopted biogenesis for the process, where life arises from existing life; it is the latter set of definitions that became dominant.

Antiquity

Presocratic Philosophers

Active in both the 6th and 5th centuries BCE, early Greek philosophers, known as physiologic in antiquity, attempted to give the phenomena of natural explanations that had previously been ascribed to the agency of the gods. The physiologic has sought the material principle or arche of things, emphasizing the external world’s rational unity and rejecting the mythological or theological explanations.

Anaximander, who believed that all the things arose from universe elemental nature, the “unbounded” or “Apeiron” or the “infinite,” was likely the first western thinker, the one to propose that life developed spontaneously from the nonliving matter. The primal chaos of the Apeiron, that is eternally in motion, served as a substratum, where the elemental opposites (for suppose, hot & cold, wet & dry) generated and also shaped the several and different things in the world.

Anaximander argued, according to the 3rd century CE’s Hippolytus of Rome, that either fish or fish-like creatures were the first ones to form in the “wet,” when acted with the sun’s heat, where these marine creatures gave rise to humans.

Aristotle

The natural philosopher Aristotle, in his biological works, extensively theorized the reproduction of different animals, whether by parthenogenetic, sexual, or spontaneous generation. The basic theory of sexual reproduction of Aristotle contended that the seed of imposed form of the male, the set of traits passed down to the offspring on “matter” (otherwise menstrual blood) provided by the female, according to his fundamental theory of hylomorphism, which held that each physical entity was identified as a compound of matter and form.

Therefore, the female matter is the generation’s material cause – it supplies the matter which will constitute the offspring, while male semen is one of the efficient causes, the factor that delineates and instigates the existence of the thing. Yet, as proposed in Animal’s History, several creatures produce not through sexual processes but by spontaneous generation.

Latin and Early Christian Sources

Vitruvius, a writer and Roman architect of the 1st century BCE, has advised that libraries be placed facing eastwards to benefit from the morning light, but not towards the west or south as those winds generate bookworms.

Aristotle has also claimed that eels were lacking in lacking milt and sex, spawn, and the passages for either. Rather, he also asserted that eels have emerged from earthworms. And then, the authors dissented. Pliny, who is the Elder, did not argue against the eels’ anatomic limits but has stated that eels can reproduce by budding and scraping themselves against the rocks by liberating the particles that become eels. Also, Athenaeus has described eels as discharging and entwining a fluid that would settle on mud and generate life.