This paper describes the origins of biomolecules hypothesis. Each different hypothesis is derived from a different scientist. It explains their claim and answers the question if the origin of biomolecules using their hypothesis. All the scientists provided evidence to help support their hypothesis. Some of the scientists had experiments to test their hypothesis. They also gave reasoning for supporting their theory. The Primordial Soup Hypothesis was introduced by the Soviet biologist Alexander Oparin in the 1920s. It states that there were chemicals in the atmosphere that formed molecules.
These molecules were brought to life by lightning and then rained down and formed a puddle. This puddle will later be known as the primordial soup. This hypothesis was tested later in the 1950s by Stanley Miller and Harold Urey by putting gasses together that were thought to be on Earth before life existed. After combining these gasses they used an electric spark to represent lighting, and amino acids, the building blocks of life, were formed. In 1988, Gunter Wachtershauser proposed a theory that stated a chemical reaction happened around deep ocean vents when the hot air pushed out of the vent and met the cold ocean water.
This was known as the Iron-Sulfur World Hypothesis. The more hot gas came out it changed the pyrite into troilite. This cycle is known as the Kreb cycle. The Kreb cycle takes place in all aerobic cells today. After the cycle repeated over and over, a cell finally formed and “enclosed the metabolic life form. ” Some scientists believe that instead of a lipid membrane around the cell there was an iron-sulfur membrane. Because it was made of iron sulfur it was a start for a chemical reaction. Because the chemical reaction occurred, it would, overtime, build up and the cells would travel away from its original place in metal bubbles.
This happening can explain how cell structures arose. Several scientists did experiments to test this hypothesis. One of the experiments reproduced the conditions of the deep sea heating vents and they looked at how iron-sulfur was able to create an organic chemical. They found that the simple would react with the iron-sulfur to create more complex molecules. In 1977, a team of scientist from the Scripps institution of oceanography discovered that there were groups of species living around hydrothermal vents deep in the ocean floor. These vents were far away from sunlight, but the species was thriving in the chemicals coming out of the vents.
This leads scientist to believe that the hydrothermal ve provided the right environment needed for life to begin in early Earth. This is known as the Deep Sea Vent Hypothesis. Scientists found methanethiol around these vents and they believe that life started from this compound. The scientist went to test this theory at the bottom of the ocean floor by the vents. They went down to measure the methanethiol that came out of the vents. Some of the vents had more methanethiol than others, but they had collected it along with other chemicals around the vents.
Some of the other chemicals suggest that microbial organic matter exists. When the sea floor is too hot it produces methanethiol. In the 1960s, Francis Crick came up with the RNA World Hypothesis. He hypothesized that organic molecules would build up on Earth. These molecules were nucleobases and sugars. They would create a chemical reaction and form ribonucleotides. The nucleotides would hook together forming a chain of RNA. The RNA folded into a shape and was able to replicate itself. It did this a bunch of times and created an abundance of RNA in Earth.
Evidence suggests that the ribosome is made up of both RNA and a protein, but the RNA is what was used in the earliest lifeforms to carry out the chemical reaction and not the protein. A scientist named John Sutherland created a ribonucleotide in a lab using chemicals that existed in the beginning of earth. Since Southerland was able to create this in a lab, it shows strong evidence that this could’ve happened in Earth’s beginning. In the 1980s several scientists were able to produce ribosomes with a limited capability. Since they were able to do this it gives more credibility to the RNA world hypothesis.
In 1982, A. Graham Cairns-Smith hypothesized that the origin of life came from a clay type inorganic substance rather than an organic compound. This is known as the Community Clay Hypothesis. Living matter gets trapped inside of the clay. The get preserved in the clay. As soon as the clay dries out and/or falls apart the wind picks it up and blows it to another location, which could fall into a stream. There the neral crystals in clay contain genetic information like DNA. The DNA in these crystals is responsible for how these amino acids should be arranged in proteins.
These amino acids helped from the other organic molecules and made the first cell which is the smallest unit of life. When Graham was working with DNA he saw that some patterns matched the patterns of certain types of minerals. Once he saw this connection he came up with the Community Clay Hypothesis. The Panspermia Hypothesis comes from the Greek philosopher Anaxagoras who lived in 500 bc-428 bc. This theory states that everything existed as a speck or “seed” of themselves. The seeds came from all over the universe and traveled through space from one location to another. Some people believe this is how life on Earth began.
There are three variations of this hypothesis. They are Interstellar (flying rocks from other planets spread the seed material from one solar system to another), interplanetary (Seeds are spread one planet to another in the same solar system, and Directed panspermia (spreading of seeds from extraterrestrials to Earth). Recent Indian and British researchers were able to get samples from the stratosphere that contained living cells. Another example to support this theory is another scientist found extraterrestrial bacteria inside a meteorite that scientists think is over four-billion years old.
Anaxagoras reasoning behind his theory is that he wondered why flesh isn’t made out of flesh and where did we come from? So he answers himself saying a being from another world made us and put us here. Different scientists have tested this panspermia hypothesis by sending microbes into space and seeing if they can stand reentry into earth’s atmosphere. These are the hypothesis for the origin of biomolecules. These hypotheses are still being tested today. Many of these hypotheses are finding new support through research and new experiments to help prove their theory.
