Around 1953, Miller and Urey mixed methane, ammonia, hydrogen, and water vapor and applied electric discharge to simulate lightning. The products were found to contain a few amino acids, which are individual links of long chain polymers called proteins, which are important in our bodies. Amino acids are normal every day chemicals. Even unto this day, there is no known process that has ever converted amino acids into a life form.
An assumption would be that even if we have enough amino acids building blocks life would still not result. Amino acids maybe the building blocks of proteins, and proteins are necessary for life, but that does not mean that amino acids are the building blocks of life as much as all the parts in the store will produce a functioning machine, there must be present all the correct parts as well as a skilful assembler.
But one often wonders, why there has been more than 50 years of debates on this issue than discussion of the facts. The realization is that discussion of the facts would inevitably led to a discussion of the subject of chirality, which is one fact some people do not even want to discuss.
Chirality is a chemical word that means handedness. Something that is a mirror image of another, your hands demonstrate chirality, your right and left hands are a mirror image of each other, hence the term handedness. Two chemical molecules may appear identical but in reality they are only mirror images of each other. Therefore chirality can exist as a right-handed or left-handed molecule and each is called an optical isomer.
It is chirality that provides the unique 3D shape for proteins and DNA, and without chirality, the biochemical processes in our bodies would not do their job.
When a random chemical reaction is used to prepare molecules having chirality, there is an equal opportunity to prepare the left-handed isomer as well as the right-handed isomer. 50/50 chance.
Up to date, all the amino acids that formed in the lab lacked chirality, including the amino acids of Miller and Urey. That points to a catastrophic failure that "life" cannot come from chemicals by natural processes contrary to a newspaper headline around 1953 Life in a test tube.
Proteins are polymers of amino acids and each one of the component amino acids exists as the "L" or left-handed optical isomer. Even though the "R" or right-handed optical isomers can be synthesized in the lab, this isomer does not exist in natural proteins.
The DNA molecule is made up of billions of complicated chemical molecules called nucleotides, and these nucleotide molecules exist as the "R" or right-handed optical isomer. The "L" isomer of nucleotides can be prepared in the lab, but they do not exist in natural DNA. There is no way that a random chance process could have formed these proteins and DNA with their unique chirality.
If proteins and DNA were formed by chance, each and every one of the components would be a 50/50 mixture of the two optical isomers. This is not what we see in natural proteins or in natural DNA.
As nucleotide molecules come together to form the structure of DNA, they develop a twist that forms the double helix structure of DNA. DNA develops a twist in the chain because each component contains chirality or handedness. It is this handedness that gives DNA the spiral shaped helical structure. If one molecule in the DNA structure had the wrong chirality, DNA would not exist in the double helix form, and DNA would not function properly.
The entire replication process would be derailed like a train on bad railroad tracks. In order for DNA evolution to work, billions of molecules within our body would have to be generated with the "R" configuration all at the same time, without error. If it is impossible for one nucleotide to be formed in the lab with chirality, how much less likely would it be for billions of nucleotides to come together exactly at the same time, and all of them be formed with the same chirality? If evolution cannot provide a mechanism that forms one product with chirality, how can it explain the formation of two products of opposite chirality?
An assumption would be that even if we have enough amino acids building blocks life would still not result. Amino acids maybe the building blocks of proteins, and proteins are necessary for life, but that does not mean that amino acids are the building blocks of life as much as all the parts in the store will produce a functioning machine, there must be present all the correct parts as well as a skilful assembler.
But one often wonders, why there has been more than 50 years of debates on this issue than discussion of the facts. The realization is that discussion of the facts would inevitably led to a discussion of the subject of chirality, which is one fact some people do not even want to discuss.
Chirality is a chemical word that means handedness. Something that is a mirror image of another, your hands demonstrate chirality, your right and left hands are a mirror image of each other, hence the term handedness. Two chemical molecules may appear identical but in reality they are only mirror images of each other. Therefore chirality can exist as a right-handed or left-handed molecule and each is called an optical isomer.
It is chirality that provides the unique 3D shape for proteins and DNA, and without chirality, the biochemical processes in our bodies would not do their job.
When a random chemical reaction is used to prepare molecules having chirality, there is an equal opportunity to prepare the left-handed isomer as well as the right-handed isomer. 50/50 chance.
Up to date, all the amino acids that formed in the lab lacked chirality, including the amino acids of Miller and Urey. That points to a catastrophic failure that "life" cannot come from chemicals by natural processes contrary to a newspaper headline around 1953 Life in a test tube.
Proteins are polymers of amino acids and each one of the component amino acids exists as the "L" or left-handed optical isomer. Even though the "R" or right-handed optical isomers can be synthesized in the lab, this isomer does not exist in natural proteins.
The DNA molecule is made up of billions of complicated chemical molecules called nucleotides, and these nucleotide molecules exist as the "R" or right-handed optical isomer. The "L" isomer of nucleotides can be prepared in the lab, but they do not exist in natural DNA. There is no way that a random chance process could have formed these proteins and DNA with their unique chirality.
If proteins and DNA were formed by chance, each and every one of the components would be a 50/50 mixture of the two optical isomers. This is not what we see in natural proteins or in natural DNA.
As nucleotide molecules come together to form the structure of DNA, they develop a twist that forms the double helix structure of DNA. DNA develops a twist in the chain because each component contains chirality or handedness. It is this handedness that gives DNA the spiral shaped helical structure. If one molecule in the DNA structure had the wrong chirality, DNA would not exist in the double helix form, and DNA would not function properly.
The entire replication process would be derailed like a train on bad railroad tracks. In order for DNA evolution to work, billions of molecules within our body would have to be generated with the "R" configuration all at the same time, without error. If it is impossible for one nucleotide to be formed in the lab with chirality, how much less likely would it be for billions of nucleotides to come together exactly at the same time, and all of them be formed with the same chirality? If evolution cannot provide a mechanism that forms one product with chirality, how can it explain the formation of two products of opposite chirality?
Last edited:
