Biogenesis and the Birth of Modern Science

By Narasimha das

The ancient Greeks, specifically the renowned philosopher Aristotle (384 B.C – 322 B.C.), believed that living things were spontaneously generated from non-living matter.

Aristotle was a naturalist who loved to observe animals and nature while taking long walks through the country. He noticed that ponds were full of various species, such as fish, frogs and tiny swimming insects. Later, in the summer months, many of these ponds would dry up and appear to become lifeless mud sinks or totally dry beds. But when the rains came, the same dry beds would fill up again with aquatic life. He wondered how all this life became regenerated. After pondering this puzzle for a long while, he finally concluded that earth itself had the power to generate life spontaneously under certain conditions. Observing the life cycles of insects on land, he came to similar conclusions: that rotting meat, animal fur and other nonliving matter had the potency to generate various forms life under specific conditions.

Aristotle was considered one the greatest thinkers of his era, so naturally his published findings circulated to nearby Arab countries, and gradually such misleading ideas spread west to European nations. Such misinformation gradually evolved into a system of superstitions and beliefs that were taught in school texts on biology and medicine.

Due, perhaps, to the liberating influence of the advent of Sri Chaitanya Mahaprabhu on Earth (1484-1532), Europe started to slowly emerge from the Dark Ages. During the Dark Ages people had no idea how or why deadly diseases like the black plague were spread. City people would pass stool and urine in buckets and then throw it out their townhouse windows, yelling a warning to pedestrians, “Loo!” (This is how the term “loo” came to mean toilet or latrine.) Some streets were, at times, ankle deep in human excrement. Surgeons had no idea of any need for cleanliness. In fact, doctors would often wear their most filthy clothes to perform surgeries with unwashed scalpels, just as field workers and street cleaners would wear filthy clothes for their work, saving their clean clothing for social affairs. Thus, many patients would “mysteriously” die shortly after even routine surgeries.

William Harvey (1578-1657) became famous for his discovery that blood circulates through the body in veins and blood vessels. In one of his writings, he mentioned that it was possible that insects may lay eggs that were too small to be seen with the naked eye. The glimmer of light from this suggestion inspired and motivated another early scientist, Francisco Redi (1626-1697), to investigate further. Soon he became convinced that the prevailing theories of his day were ill-conceived. He demonstrated through experiments that life was not be generated spontaneously from non-living matter and that such conjectures had no basis. His controlled experiments involved sterilization through heating and various means of sealing containers and then comparing these with non-sterilized open containers of the same organic substances. He boldly propounded his views that life was generated not spontaneously from dead matter but from living organisms, some that were too small to be seen with the naked eye or laid eggs too small to be seen.

People of his day were stunned by this fantastic new theory. Aristotle had been highly regarded in the West for many centuries as one of the greatest thinkers and naturalists of all time. People wondered, “How could Aristotle have been so wrong?”

To prove his theory, Redi devised several interesting experiments to demonstrate that life comes from life. These experiments were literally the birth of modern sciences, specifically biology and medicine, which relies on controlled observations and experiments to demonstrate the truth or fallacy of theories like Redi’s and Aristotle’s. Redi’s experiments gave rise to modern-day knowledge regarding food preservation through sterilization, and sanitation through disinfecting. He had demonstrated in many of ways that life is generated only from other living things and that non-living matter had no power to generate life on its own. Scientists then began forming groups for the sake of exchanging their findings derived through various means of experimentation and observation. Redi and his followers strongly propounded their new understanding known as biogenesis, which establishes that life arises only from previously existing life and not from non-living matter.

A breakthrough came when a humble lens grinder, Antonio Van Leeuwenhoek (1632-1723), refined his art with the help of a renowned spectacle maker. He learned how to grind a precision magnifying lens and how to achieve further magnification by stacking lens in a tube. In this way he created the first known microscope. With his microscope he was able to observe microbes for the first time, and this led to many new discoveries. At first other scientists were doubtful about the existence of microbes because they were unable to match the precision and power of Leeuwenhoek’s microscopes.

Soon Leeuwenhoek’s discoveries of microbes were verified by other scientists, yet many scientists clung to their belief that microbes themselves were spontaneously generated from non-living substances. Aristotle had taught that non-living substances can create life under certain conditions, and this widely accepted belief had been around for centuries. Long held beliefs die hard.

Despite clear evidence supporting biogenesis, many scientists challenged the idea for another 150 years. In the latter part of the nineteenth century, a member of the French Academy of Sciences, Dr. Pouchet, published a compelling book that attempted to reaffirm the idea that micro-organisms were spontaneously generated from non-living matter. His book was highly lauded by scientists worldwide.

Dr. Pouchet’s findings did not go unchallenged for long. Louis Pasteur read Pouchet’s book and wrote to him explaining several discrepancies in his methods, findings and conclusions. Pasteur was considered one of the top scientists of his times, especially in France, and he is still considered one the most important scientists of the modern age. Pasteur strongly refuted Pouchet’s ideas through a series of experiments and debates. The scientific community and general public were divided in their opinion on this issue. Many challenges and counter-challenges went back and forth and gave rise to varieties of experiments under careful controls.

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