Exploratour - Life on Earth

The Miller Urey experiment helped show how it was possible to derive some of the components of life from isolated molecules.
Corel Photography

In the 1950's, biochemists Stanley Miller and Harold Urey, conducted an experiment which demonstrated that some of the basic elements of life, including amino acids, could be formed spontaneously by simulating the conditions of Earth's early atmosphere.

They designed a tube which held a mix of gases similar to those found in Earth's early atmosphere, namely water, ammonia, and methane, along with a pool of water to simulate the early ocean, and delivered an electric current to simulate lightning, into the gas-filled chamber. They found that several organic amino acids (long and complex molecules) had formed spontaneously out of the combination of these simple elements. These molecules collected together in the pool of water to form coacervates.

Their experiments lent support to the theory that the first life forms arose spontaneously through naturally occuring chemical reactions. However, there are still many skeptics of this theory who remain unconvinced. British astrophysicist, Fred Hoyle, compares the likelihood of life appearing on Earth by chemical evolution "as equivalent to the possibility that a tornado sweeping through a junkyard might assemble a Boeing 747 from the materials therein".

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