Some General Problems Relative to the Origin of Life on Earth or Elsewhere

Abstract

From the standpoint of chemistry, the following properties of life appear to be important. Living things maintain metabolic processes, that is, chemical reactions in which compounds of one kind are absorbed by living things and compounds of another kind excreted. Animals absorb compounds containing high free energy and excrete those with low free energy. Plants absorb certain compounds of low free energy, i.e., carbon dioxide, excrete compounds of high free energy, oxygen plus carbohydrates, for example, and at the same time maintain a complex metabolism in which high energy compounds are used for living processes. This dynamic metabolic process is an exceedingly important characteristic of living things. In the second place, living organisms are distinguishable from their surroundings. We would not consider an ocean in which chemical reactions of a general type such as that mentioned above were taking place as a living organism. A living organism has form and structure, and this is of a very complicated and intricate kind in the case of modern organisms. The possibility of maintaining these exceedingly complicated and highly organized bodies can only be done in the face of the degenerating processes that are predicted on the basis of natural accidents by very special arrangements. Inevitably a single living organism will degenerate or be destroyed by accident. Hence the persistence of living things in the face of this degenerative tendency can only be maintained by some other mechanism, and that mechanism is the replicative characteristic. Living organisms are able to produce additional living organisms of a fairly perfect or at least operative kind and hence make allowance for the destruction of organisms that have been damaged or degenerated. The replicative function is a necessity. The free energy for this process which enables the living organism to overcome the requirements of an increase of entropy in all processes is, of course, free energy from the sun.