Re: What is primordial soup?

Hallo Christina,

Thanks for your question. "Primordial soup" is a rather old fashioned term, used to describe a theory for how the organic compounds essential to life may have formed on earth.
In the 1950s, 2 scientists named Urey and Miller performed an experiment in which they mixed gases thought to have been present in the ancient atmosphere (water vapour, hydrogen, ammonia and methane) and passed electrical current through them. These simple compounds reacted to form many of the more complex molecules that are found in living organisms (e.g. simple sugars and amino acids). So it was envisaged that on the early earth, lightning could have created biochemical molecules by the same process. These would have been washed down by rain into pools, forming dilute mixtures of organic molecules which were the basis for life. You can read an interview with Stanley Miller at this page.

In fact, Darwin himself envisaged such a process, talking of a "warm little pond" in which life may have originated. However, there is a lot of debate about how the first simple living things originated from organic molecules. Some people believe that a thin soup of molecules in a pond is an unlikely place and that life may have originated elsewhere, such as deep in the ocean. Others prefer a theory called panspermia in which organisms came to earth from space (though this ignores the problem of how that life originated!)

This is probably the biggest unsolved problem in biology today. If you find it interesting, I always encourage people to look at the Talk.Origins archive. And if you think you can solve the problem, you can win big money at the Origin of Life prize page!

Neil Saunders