520 ANNUAL REPORT SMITPISONIAN INSTITUTION, 196 2 



stances in the units of living matter called cells. It is reasoned, 

 therefore, that if similar substances were first brought together in 

 pools of water or along the shores of the primary seas, the same chem- 

 ical reactions would take place as at present, and thus give the begin- 

 ning of life. This theory has been particularly well worked out by 

 Oparin (1938, 1961), whose ideas have been so closely followed by 

 others, as by Wald (1954), Adler (1957), and Lehrman (1961) here 

 cited, that fortunately we have only one plausible theory on the sub- 

 ject to deal with, which fact in itself is a good recommendation for it. 

 The general reader may find the theory well presented by Piatt (1961) 

 in the Reader's Digest. Briefly reviewed, this modern scientific con- 

 cept of the origin of life is as follows : 



Among the chemicals poured into the waters of the earth by the 

 rains were simple organic compounds freely formed in nature. As 

 time went on, some of these substances came together in small groups 

 forming droplets of organic material in a gelatinous or colloidal state, 

 such as are known as coacervates. When organic molecules get to- 

 gether in a water medium, things begin to happen. Some are broken 

 down into simpler molecules, some of which are thrown out, while 

 others are taken in from the surrounding water and assimilated to 

 restore the internal balance. Thus metabolism^ the basic activity of 

 life, began on a small scale. Though most of the coacervates were 

 highly unstable and soon Avent to pieces, those in which a balance 

 of output and intake was preserved endured. These persisting coa- 

 cervates could now be said to be alive. With feeding, the mass became 

 too large and simply broke into two parts, perhaps as a lump of jelly 

 might be divided. Thus the simple organisms multiplied ; those best 

 fitted to survive were preserved by natural selection and became the 

 progenitors of future life forms. In the words of Adler (1957), 

 "through the slow accumulation of changes during hundreds of mil- 

 lions of years, coacervates finally developed that liad the complex, deli- 

 cately balanced, and stable chemical processes that we call life." 



Some writers, as Moskin (1962), refer to the origin of life in mat- 

 ter as "creation" of life, but clearly there is no act of creation mvolved. 



The materials that first became living matter had been in existence 

 since tlie beginning. They were simply brought together under cir- 

 cumstances that allowed their inherent energies to interact in a new 

 way. 



Tlie chemical activities of living matter require a constant supply 

 of energy. The principal source of life's energy today is the oxida- 

 tion of food, but the theorists tell us that when life began and for a 

 long period afterward there was no oxygen or very little in the earth's 

 atmosphere. At this time it is supposed that energy was produced 

 by fermentation, a very slow process, but there were millions of years 

 during which living matter could leisurely develop and improve. It 



