32 



LIFE: ITS BEGINNINGS AND NATURE 



hoi (C2H5OH), and glucose (CoHi^Oc). 

 Others have incorporated nitrogen into the 

 molecule, in addition to carbon and oxygen, 

 to form proteins, the complex compounds 

 out of which living things are built. There- 

 fore, conditions must have been right at this 

 early period to bring about atomic combi- 

 nations that produced these complex mole- 

 cules, which later became the integral part 

 of living material. There is reason to believe 

 that this could have taken place because 

 in the laboratory it has been possible, with 

 the use of ultra-violet light, to bring about 

 the conversion of simple substances such 

 as methane (CH4) and cyanogen (CN), 

 containing carbon, nitrogen, and hydrogen, 

 into complex organic compounds. If, dur- 

 ing the days of the young earth, more ultra- 

 violet light reached its surface than today, 

 great oceans of these complex organic mole- 

 cules, like great pools of organic "soup," 

 could have formed. 



These organic molecules could have 

 formed aggregates that resembled proteins. 

 These, once formed, must have found some 

 way to organize themselves into repro- 

 ducible entities. Such a condition is alto- 

 gether possible and not pure speculation 

 because we have reproducible protein par- 

 ticles with us today, namely, viruses, these 

 invisible (under a light microscope) mi- 

 crobes so minute that they pass through the 

 very small pores of a porcelain filter (Fig. 

 2-8). They cause many plant and animal 

 diseases, including such dread human 

 maladies as poliomyelitis, yellow fever, and 

 many others. Viruses are composed of pro- 

 tein and very little else; furthermore, they 

 reproduce themselves when placed in their 

 normal environment, which is the internal 

 parts of cells. They are able to organize 

 the surrounding organic compounds into 

 their own material and thus duplicate 

 themselves. 



Assuming that the original protein mole- 

 cules were like the familiar present-day 

 viruses, they would be forced to consume 

 other molecules in order to reproduce 



themselves just as the viruses do within 

 cells. There would come a time, however, 

 when all of the organic molecules in these 

 oceans of molecular "soup" would be used 

 up. Some time before this suicidal state was 

 reached these particles must have evolved 

 a method of utilizing simpler and simpler 

 substances to construct their own frame- 

 work. These would be substances such as 

 carbon dioxide and water that were pres- 

 ent in great abundance. Once this was 

 achieved, they could continue indefinitely 

 without depending on a supply of complex 

 compounds for their subsistence. This is 

 the way plants manufacture their products 

 today. 



From non-living to living 



If viruses are considered to be alive, the 

 gap between the living and non-living has 

 been spanned. Although, in general, viruses 

 exhibit characteristics of living things, they 

 do possess one property that is not usually 

 associated with life. When properly treated, 

 at least one virus, tobacco mosaic virus, will 

 form crystals and remain in a state of abso- 

 lute inactivity for an indefinite period of 

 time. Living things may hibernate, form 

 resting cysts, or otherwise remain relatively 

 inactive for periods of time, but such vital 

 processes as taking in of oxygen and giving 

 off of carbon dioxide are still observable 

 although in much reduced amounts. The 

 crystalline virus does not demonstrate these 

 properties. Indeed, for all purposes it seems 

 to belong to the inanimate world. Chemists 

 usually consider any substance that crystal- 

 lizes to be a relatively pure compound; it 

 would appear, then, that the virus is a near- 

 pure protein, nucleoprotein to be exact. 



When this apparently inanimate crys- 

 tal is placed in the tobacco plant cell it 

 bursts into activity, taking on all of the 

 properties of living things. Is it possible 

 that here is a form existing at the border- 

 line between the living and non-living 

 worlds? Perhaps so. At any rate, it gives 

 us a possible clue as to how life originated. 



