Microbiology is the scientific study of organisms that are too small to be viewed using the naked eye such as bacteria, fungi viruses algae and protozoa. Collectively, these organisms or if they are known to cause diseases they can also be given the name pathogens or germs.Microbiology involves coming up with hypotheses that seek to explain various factors related to these organisms such as their structure, their life cycles, their effects on other organisms including humans and any other relevant aspect or field. These hypotheses are developed through observation and critical analysis of known factors concerning the microorganisms (Alexander & Numbers, 2010). After the hypotheses have been defined, experiments are carried out in order to prove or disprove the hypotheses’ statement or definition of a phenomenon and if the experiments repetitively result in a predicted outcome according to the initial hypothesis then it is said that the hypothesis is true or supported. If the contrary happens and the experiments’ results do not support or agree with the hypothesis then it is said to be false or disapproved. Through these observations, hypotheses and experimentation on microorganisms or microbes, scientists get to learn more about them and are then able to manipulate or use these microorganisms to produce intended effects (Bastian & Strick, 2001).
History
The single biggest boost to the study of microorganisms and microbiology as a whole was the invention of the microscope. This came up in the mid 1600’s as a result of the work of two amateur scientists named Robert Hooke and Anton van Leeuwenhoek. These two developed and began using the first crude microscopes and by 1677 Leeuwenhoek was credited as observing the first “small animals” or microbes using a microscope (Bastian & Strick, 2001). Scientists at the time believed that these tiny organisms came about spontaneously from either combination of certain inorganic matter or the decomposition and rotting of organic matter. This theory came to be known as abiogenesis or the spontaneous generation theory.
Spontaneous generation stood for many years with the scientists agreeing with it giving examples of Jan Baptist van Helmont’s experiments with a willow tree for 5 years. This experiment showed a great increase in the mass of the willow while the soil in which it was growing did not show a significant decrease in mass (Alexander & Numbers, 2010). This led him to the conclusion that microorganisms in the willow were generated spontaneously. Other experiments that were quoted to prove the theory of spontaneous generation were William Harvey with his dissections of deer, and some even referenced as far back as Aristotle who believed that living things came to being because of the things because the nonliving material contained pneuma (vital heat) combining the five elements which made up matter. Other scientists such as Louis Jablot managed to demonstrate the science behind the theory of spontaneous generation (Bastian & Strick, 2001).
Early scientific disapproval of spontantenous generation theory
A number of early scientific experiments by notable biologists were done disapproving the spontantenous generation theory. In 1668, Italian scientist Francesco Redi undertook an experiment on the creation of maggots by spontaneous creation. He used three pieces of meat, where he placed one piece under a piect of paper; flies could not lay eggs onto the meat and subsequently no maggots developed (Alexander & Numbers, 2010). He noted maggots on the outer surface of the the paper covering the jar. He left the second piece of mat in the open air; maggots developed on the open jar after some days. The final test involved overlaying the piece of meat with cheesecloth; flies laid eggs into the cheesecloth and no maggots developed upon removal. However, placing the cheesecloth with the eggs onto a fresh piece of meat would result into development of maggots. This proved that the flies resulted from the eggs as opposed to spontanteneous generation (Bastian & Strick, 2001).
In another experiment, Italian scientist Lazzaro Spallanzani (1729-199) sought to review data and experimental designd of Redi and Needham. He designed his own experiment by placing broth in two separate bottles, boiled the broth in each bottle, and them sealed one of the bottle and left the other open. After a few days, he observed that the open bottle showed small livings things clearly observable through a newly invented microscope (Bastian & Strick, 2001). However, the closed bottle had no signs of life. The experiment discounted spontaneous generation as a reliable theory. The experiment was however criticized by proponents of spontaneous generation on grounds that air was a prerequisite for development of life in the closed bottle.
In 1862, the Frech scientist Louis Pasteur (1822-1895) entered a contest organized by The French Academy of Sciences to provide new perspective on the controversial issue of spontanteous generation. He disapproved the spontaneous generation theory by designing several S-curved neck bottles oriented downward to avoid gravity from disallowing access by airborne foreign materials. He boiled the broth inside bottle and noted that there was no life inside the jar for one year. Pasteur then exposed the jar directly to air by breaking off its top (Alexander & Numbers, 2010). Within days, he observed life forms in the broth. He reckoned that trapped airborne particles and dust in the S-shaped nect of the bottle hampered development of life unless the obstacle was eliminated. He conclude that the contamination as a result of life-forms in the air. As such, Pasteur was successful in convincing the scientific world that life did not arise from non-living matter even when exposed to air (Bastian & Strick, 2001).
Spontaneous generation in modern microbiology
In modern microbiology, spontaneous generation has become an obsolete school of thought pertaining to the ordinary formation of living things from nonliving material. More advanced scientific studies and documentation of various life cycles fof different life forms have definitely disapproved the spontanteous theor. It must be understood that spontaneous generation as a theory was popular among early biologists due to their relatively little knowledge of microorganisms. This is not to say that they were stupid or did sloppy experiments. Indeed they undertook careful experiments and their interpretations of results was informed by their biases (Alexander & Numbers, 2010). This is especially the case considering that bias and fallibility are inherent of all human experiement in the discipline of science of any generation. It is the self-correcting nature of the discipline that reduces the effect of such biases on widely held theories. In the days of early scientists, spontaneous generation theory attracted much scientific experimentation as it was a seductive and generally held belief. However, more intense experimentation has served to dispel the theory, effectively rendering it obsolete in modern day microbiology.
References:
Alexander, D. R., & Numbers, R. L. (2010). Biology and Ideology from Descartes to Dawkins. Chicago: University of Chicago Press.
Bastian, H. C., & Strick, J. E. (2001). Evolution and the spontaneous generation debate. Bristol: Thoemmes.
