WUAI' lURlHKK RESEARCH xMAY TEACH US 135 



of 'organic' molecules. We might find fossilized, structurally pre- 

 served, parts of this early life, just as we have now found deposits 

 formed by such life. But the fossil material will always be extremely 

 scanty. We will, at the most, have a fossil here, another there, but 

 never enough to permit the construction of evolutionary lines com- 

 parable to those we have established for the later evolution of the 

 higher life forms of more complex morphological structure. 



W^HAT FURTHER RESEARCH MAY TEACH US 



It is to be hoped that further research will bring us more of those 

 v'aluable discoveries of early fossils, be they from the primeval pre- 

 actualistic period or from the dawn of our present life. By such 

 lucky finds it will in future be possible to furnish a much more 

 substantial documentation of early life than we have at present. 



Moreover, we may legitimately hope that more intensive mapping 

 of the Old Shields will yield better correlations between the series 

 of rocks by which they are built up. With the availability of more 

 absolute datings it will then be possible to assign more reliable 

 absolute ages to these fossil finds, both old and new. 



Another conceivable result of future research, a result very im- 

 portant to my mind, will be that more will be knowoi about the 

 environment of early life. If we have more places where sediments 

 can be said to have formed either under primeval anoxygenic or 

 under the present oxygenic atmospheric conditions, and if such 

 localities could be dated more reliably, it would be possible to define 

 more narrowly the time of transition from the primeval to the present 

 atmosphere. 



If we could some day arrive at an estimate of the time this transi- 

 tion actually took, this would in turn give us some idea of the actual 

 r?.te of biogenic production of free oxygen; of great value, of course, 

 to biologists interested in the rate of metabolism of early life. 



CLOSING REMARK 



Having thus summarized what we know, what we shall never know, 

 and what we hope further research will teach us in years to come, 

 we may arrive at a final conclusion. This is that the findings of 

 geology are in complete agreement with the modem biological views 



