Does the Miller-Urey experiment tell us anything about how life originated on Earth?

Do the Miller-Urey experiments simulate the early Earth?
The Miller-Urey experiments

There are two problems related to the origin of the first living cell, on atheism:

  1. The problem of getting the building blocks needed to create life – i.e. the amino acids
  2. The problem of creating the functional sequences of amino acids and proteins that can support the minimal operations of a simple living cell

Normally, I concede the first problem and grant the atheist all the building blocks he needs. This is because step 2 is impossible. There is no way, on atheism, to form the sequences of amino acids that will fold up into proteins, and then to form the sequences of proteins that can be used to form everything else in the cell, including the DNA itself.

Today, let’s take a look at the problems with step 1.

The problem of getting the building blocks of life

Now you may have heard that some scientists managed to spark some gasses to generate most of the 20 amino acids found in living systems. These experiments are called the “Miller-Urey” experiments.

The IDEA center has a nice summary of origin-of-life research that explains a few of the main problems with step 1.

Miler and Urey used the wrong gasses:

Miller’s experiment requires a reducing methane and ammonia atmosphere,11, 12 however geochemical evidence says the atmosphere was hydrogen, water, and carbon dioxide (non-reducing).15, 16 The only amino acid produced in a such an atmosphere is glycine (and only when the hydrogen content is unreasonably high), and could not form the necessary building blocks of life.11

Miller and Urey didn’t account for UV of molecular instability:

Not only would UV radiation destroy any molecules that were made, but their own short lifespans would also greatly limit their numbers. For example, at 100ºC (boiling point of water), the half lives of the nucleic acids Adenine and Guanine are 1 year, uracil is 12 years, and cytozine is 19 days20 (nucleic acids and other important proteins such as chlorophyll and hemoglobin have never been synthesized in origin-of-life type experiments19).

Miller and Urey didn’t account for molecular oxygen:

We all have know ozone in the upper atmosphere protects life from harmful UV radiation. However, ozone is composed of oxygen which is the very gas that Stanley Miller-type experiments avoided, for it prevents the synthesis of organic molecules like the ones obtained from the experiments! Pre-biotic synthesis is in a “damned if you do, damned if you don’t” scenario. The chemistry does not work if there is oxygen because the atmosphere would be non-reducing, but if there is no UV-light-blocking oxygen (i.e. ozone – O3) in the atmosphere, the amino acids would be quickly destroyed by extremely high amounts of UV light (which would have been 100 times stronger than today on the early earth).20, 21, 22 This radiation could destroy methane within a few tens of years,23 and atmospheric ammonia within 30,000 years.15

And there were three other problems too:

At best the processes would likely create a dilute “thin soup,”24 destroyed by meteorite impacts every 10 million years.20, 25 This severely limits the time available to create pre-biotic chemicals and allow for the OOL.

Chemically speaking, life uses only “left-handed” (“L”) amino acids and “right-handed” (“R)” genetic molecules. This is called “chirality,” and any account of the origin of life must somehow explain the origin of chirality. Nearly all chemical reactions produce “racemic” mixtures–mixtures with products that are 50% L and 50% R.

Two more problems are not mentioned in the article. A non-peptide bond anywhere in the chain will ruin the chain. You need around 200 amino acids to make a protein. If any of the bonds is not a peptide bond, the chain will not work in a living system. Additionally, the article does not mention the need for the experimenter to intervene in order to prevent interfering cross-reactions that would prevent the amino acids from forming.

Now keep in mind that even if you get the building blocks, you are left with the sequencing problem. Like the letters of the words in this blog post, the building blocks of life also need to be put in a meaningful sequence in order to do work in a living system – but that’s another topic for another day.

5 thoughts on “Does the Miller-Urey experiment tell us anything about how life originated on Earth?”

  1. A scientist walked up to God and said, “We don’t need you any more. We can do all the things You’ve done in the lab.”
    God said, “Oh? Interesting. Please prove it.”
    The scientist reached down for a handful of dirt but God said, “Get your own dirt.”
    If they have to take something already crated to try, what’s the use?

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  2. Atheists also jump past the information, replication and repair problem of life. And that once organized to life things want to remain living. A rock does not care if it is a mountain, a boulder or a grain of sand it follows natural law and processes. Living things actually repair itself, regenerate etc to stay organized in a way we seem to call life. There is no logical naturalist explanation I can see for this behaviour since it is not like we see spontaneous life occurring ever by any scientific test.

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  3. The Miller Urey also made mostly contaminants with few building blocks, so it had an elaborate setup compared to all the simple hot pools of life scenarios you see in all the Darwin fables of life.

    And for how long all the actually useful stuff would survive while waiting for more useful stuff to randomly generate it is useless. It is as if they have never faced biological degredation suddenly when they need to wait millions of years for things to assemble at the same time and place

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  4. There are many problems with the Miller-Urey experiment. One of the most important is that its primary product was formic acid (HCOOH). Amino acids are two handed molecules and have both an Amino (NH3) group and Carboxyl (COOH) group attached to the carbon atom. To form proteins, water (H2O) is removed to form the peptide bond and increase the size of the forming protein. Formic acid is a one handed molecule. It will happily attach itself to any chain that is forming, but since it doesn’t have an amino group, it will stop any additional amino acids from attaching to the growing protein. Therefore no spontaneous protein formation therefore no spontaneous formation of life.

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