The evolution of a living organism, as well as pre-biotic molecular evolution, seems to be inconsistent with the second law of thermodynamics. When a bacterium is compared with some other higher organism, it is clear that all evolution tends to order more and larger molecules into more complex systems. The trick is the radiation of heat from the Earth. The Earth is loosing gravitational energy (～10³¹Joule) obtained from the accretion of asteroids during its birth 4.55 Gyr ago. Energy loss implies a decrease in entropy which in turn requires ordering of the Earth. As components of the Earth, the lighter elements such as H, C, N, and O at the surface must also evolve to larger molecules and ultimately to living organisms, so that the entire surface of the Earth is now covered by low entropy materials of life.

  Thus, the entropy decrease of the Earth is responsible for the evolution of living organisms. The above argument suggests a new scenario for the origin of life as well as its source, biomolecules. The heavy fall of the extraterrestrial objects containing metallic iron into the ocean would produce a reducing atmosphere thus generating a wide variety of organic molecules at about 4.0 Gyr ago. Of these, only hydrophilic and clay-affinitive molecules could have survived the environment of strong UV radiation and weakly oxidation, because they could be immersed in seawater and be adsorbed on clay particles that were finally deposited on the seabed.

  A recent shock recovery experiment simulating the heavy fall of meteorite into the ocean supports the scenario of the origin of organic molecules. Various biomolecules has been formed in that experiment. Therefore, the above arguments may be answers for the fundamental questions on the life why living organisms have to evolve and why biomolecules are all hydrophilic and clay-affinitive. A further scenario of pre-biotic molecular evolution can be seen elsewhere.