How Life Began on Earth

By Shlomo Maital


Miller and Urey                         …. And their famous experiment


   Stephen Hawking’s brilliant PBS series Genius has a segment on how life began and evolved. In it the amazing 1952 chemistry experiment of Stanley Miller and Harold Urey (U. of Chicago) was described. The experiment shed light on how life began on earth.

     The experiment was beautifully simple. We know now that life is mainly made of proteins, and proteins are made up of amino acids.   But how did amino acids form? And what do amino acids do for us?

  • In the brain, glutamate is the main neurotransmitter (sending signals from one neuron to another, known as thinking) as neurotransmitters;   hydroxyproline is an important component of our connective tissue; glycine is crucial for red blood cells (that carry oxygen to all parts of the body); and another amino acid carries fat cells (lipids).

       Miller and Urey took methane gas, ammonia, and hydrogen gas, the gases prevalent in the earth’s atmosphere billions of years ago; they boiled water to create ‘clouds’ in the atmosphere; and added sparks, representing the lightning then occurring. Basically a very simple simulation of the gases in the earth’s atmosphere as it was when early life first formed, with some electrical energy from lightning.

       They ran the experiment for a week, then opened the flask and checked to see what happened.

         They found that three amino acids were formed. Amino acids are made of carbon, hydrogen, oxygen and nitrogen. The experiment showed how amino acids could have formed in the earth’s atmosphere…and, presumably, life began later, as the amino acids combined and became complex.

           For those who love the Bible, does this demean our faith? Not in the least. I asked a very religious relative about this, and his response was that evolution, and the Urey experiment, confirm the Biblical creation account, rather than deny it.   The beauty and complexity of all the forms of life that evolved from a handful of amino acids are surely inspiringly divine in their nature.

     As a postscript:     After Miller’s death in 2007, scientists examining sealed vials preserved from the original experiments were able to show that there were actually well over 20 different amino acids produced in Miller’s original experiments.