Author: Jefferson Lin
Editors: Yanxi Chen and Shirley Chen
Artists: Gianluca Zhang
When you think of living organisms, you associate them with mammals, insects, and parasites. But, how did they come to be? Species have adapted and evolved for millions of years to branch out to millions of species today. But what was the first? What was before the first living organism? When you think of an ancient organism, your intuition would be the dinosaurs. They roamed the Earth millions of years ago and were wiped out by an asteroid. But, dinosaurs were not the first to roam the earth nor the first to be extinct. The main theories in the scientific community on how the origin of life is spontaneous generation, deep sea vents, and the Oparin and Haldane theory.
Deep Sea Vents Theory
A popular consensus in the scientific community is that life rose from the water as Earth was engulfed in water before the first living organism appeared. It was recorded that the first living organism, a bacteria, was found in the first oceans. Now, before we dive into this theory, let's talk about how something can actually be constituted as "living". The organism needs to harness carbon dioxide in order to create the building blocks of life, such as amino acids. The theory of how life originated was 3.7 billion years ago when it was theorized that the ocean was acidic and filled with positively charged protons. On the other hand, deep within the first ocean lies sea vents that allow seawater to interact with the minerals that appeared from the earth's crust to create an alkaline environment where hydrogen lies. However, to create a chemical reaction between these different groups, a power source was needed. Fortunately, during this time, the earth was highly concentrated with carbon dioxide to create enough opposite charges to strike. Now with all these events happening simultaneously, a chemical reaction was able to occur in the deep sea vents as they were a warm area filled with rich minerals like iron and sulfur on their walls that separated from their cold counterpart: the rest of the ocean. In this area, other important complex organic compounds like RNA, a complex sequence of amino acids, and cellular membranes for protection were chemically combined. With the creation of amino acids from the chemical reaction derived from the lightning, rich carbon dioxide, and hydrogen, and the richness of the vents to create new vital components, life was able to start.
Spontaneous Generation Theory
By far the most well-known theory of the origin of life; Spontaneous generation. This theory was composed by Aristotle, a Greek philosopher from the 300 BC time period and he is one of the great philosophers that was ahead of his time. This idea of spontaneous generation came to Aristotle when he discovered that new animals have been appearing on land that was previously never seen there before. Thus, he created the theory that life appeared from non-living things. For years, because of how notorious Aristotle was and how technology and advancements in knowledge were lacking, this theory has been the theory of the origin of life for 2 millennia. However, during the 20th century, many scientists, the most notable being Louis Pasteur, were trying to dispute the spontaneous generation theory. Louis Pasteur’s famous experiment, also known as the swan neck flask experiment involved boiling broth in a flask. He boiled the broth until no microorganism was present. The flask was designed to allow air in and dust and other small particles out. From the experiment, he learned that no matter how long he waited, no microorganisms were able to grow in the environment, thus disproving spontaneous generation.
The Oparin and Haldane theory
Recently (relative to how long this theory has been accepted), new theories have also started to appear, such as the deep sea start and the more accepted theory, the Oparin and Haldan theory, also known as the biochemical theory of evolution. This theory is the most accepted theory of the origin of life and it is theorized by Alexander Oparin and John Burdon Sanderson Haldane. Theorized in the 1920s, Oparin and Haldan believed that organic molecules could be formed from abiogenetic materials in the presence of an external source. The source of energy is not exactly known, as it could have multiple sources. An experiment that supports this theory is by Friedrich Wöhler who created urea from two inorganics by using oxidation, thus supporting Oparin and Haldan. Their theory is a combination of the deep sea vent theory plus the experiment by Friedrich Wöhler to create the most accepted theory of the origin of life on Earth.
Citations:
“Spontaneous Generation Theory.” Spontaneous Generation Theory, BYJUS, Admin, 9 August
2022, https://byjus.com/biology/spontaneous-generation-theory/
“Lightning May Have Sparked Life on Earth.” Lightning may have sparked life on Earth, CNN,
29 September 2022, https://amp.cnn.com/cnn/2021/03/16/world/lightning-early-earth
life-scn-trnd/index.html
“Abiogenesis.” Abiogenesis, Encyclopedia Britannica, 29 September 2022,
https://www.britannica.com/science/abiogensis
“ Aristotle.” Aristotle, Encyclopedia Britannica, 29 September 2022,
https://britannica.com/biography/Aristotle
“Origin of Life: Did a Simple Pump Drive Process?” LiveScience, Purch, Ghose, Tia, 10
January 2013, https://www.livescience.com/26173-hydrothermal-vent-life-origins.html.
“Early German Physician First to Synthesize Urea.” Early German Physician first to Synthesize
Urea, Shampo, M.A. & Kyle R.A., 2022,
https://www.mayoclinicproceedings.org.article/S0025-6196(12)60740
X/pdf#:~:text=Friedrich%20W%C3%B6hler%20was%the%20first,silber%20
cuanate%20to%20ammonium%20chloride
“ Deep Sea Vents had Ideal Conditions for Origin of Life.” Deep Sea Vents had Ideal Conditions
for Origin of Life, Ucl. 6 May 2022, UCL news,
life#:~:text=By%20creating%20protocells%20in%20hot,vents%20rather%20than%20shallow
20pools.
“ Pasteur Swan Neck Flask Experiment.” Pasteur Swan Neck Flask Experiment, Pasteur
Brewing, 20 February 2021, https://www.pasteurbrewing.com/pasteur-swan-neck-flask
experiment/#:~:text=In%20his%20famous%20experiment%2C%20Louis,microorganisms%2
which%20were%20already%20present.
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