Zombie Science

The Miller-Urey Experiment

By the late 1990s, the 1953 Miller-Urey experiment (MU) had been thoroughly debunked. That’s why Jonathan Wells included it in his 2000 book, Icons of Evolution, as an example of one of the evolutionary myths the scientific establishment continues to prop up.¹

Today, if you google MU, the top results still reference it as “groundbreaking” and “one of the first successful experiments demonstrating the synthesis of organic compounds from inorganic constituents in an origin of life scenario.”² Interestingly, that article and others like it describe MU as having “simulated the conditions thought at the time to be present in the atmosphere of the early, prebiotic Earth” (emphasis added). Why the qualifier?

Bad Chemistry

When Stanley Miller and his PhD advisor Harold Urey conducted the experiment, their setup was simple and straightforward. They filled large glass flasks with gases simulating the atmospheric conditions thought at the time to represent those on the early Earth: hydrogen, ammonia, methane, and water vapor (importantly, they did not include oxygen). They ran an electrical current through the mixture to mimic the effect of lightning and quickly produced two of the elementary building blocks of life, the amino acids glycine and alanine.

Later geophysical and geochemical research determined that the assumptions Miller and Urey had made about the environmental conditions on the early Earth were wrong. We now know that the atmosphere consisted of nitrogen, carbon dioxide, carbon monoxide, and water vapor. Those studies also determined that some free oxygen was present. And oxygen, even in trace amounts, tends to shut down prebiotic chemistry.³

In addition, MU used a continuous charge of electricity to simulate lightning. But lightning comes in flashes. When later researchers used non-continuous, sudden bursts of electric current to re-create the results of MU, they produced no amino acids.

Weak Sauce

Amino acids are the building blocks of polypeptides, which, in turn, must be assembled to form proteins, which must each be folded and connected to other proteins in very specific ways. MU produced two—amino acids, not proteins.

There are 20 different kinds of amino acids, and proteins are composed of strings of up to 3000 of them. The median number in a simple bacterial protein is 267; in a human protein, it is 375.4 And there are about 20,000 different kinds of proteins in the human body.

To say MU demonstrated “the synthesis of organic compounds from inorganic constituents” is more than a stretch; it’s a fantastical extrapolation. But to continue saying it knowing that MU was conducted using a non-analogous method and with the wrong initial conditions is downright intellectually dishonest.

Walking Dead Science

In 2017, Wells followed up Icons of Evolution with Zombie Science: More Icons of Evolution, in which he noted that MU has been cited in biology textbooks published as recently as 2016. Though long discredited, the Miller-Urey fantasy continues to shuffle on. Just like the walking dead. •

Notes
1. Jonathan Wells, Icons of Evolution: Science or Myth? Why Much of What We Teach About Evolution Is Wrong, (2000), pp. 9-27.
2. “Miller-Urey Experiment,” Wikipedia (accessed June 3, 2024).
3. Fazale Rana & Hugh Ross, Origins of Life: Biblical and Evolutionary Models Face Off (Navpress, 2004), pp. 100-101.
4. Ron Milo, Cell Biology by the Numbers, “How Big Is the ‘Average’ Protein?”