THE DANGERS OF COMPARATIVE BIOCHEMISTRY 125 



Geology has seen similar reasoning in comparative anatomy, where 

 'simple' has also been largely confused with 'primitive' and with 

 'early'. Many have been the trees of evolution in which members 

 of parallel or converging evolutionary lines have been mixed, often 

 accompanied by an absolute disregard for the stratigraphical position, 

 i.e. the relative age of those forms. Imaginary- forefathers were sup- 

 posed to have sired entirely non-related offspring, sometimes tens of 

 millions of years their older, not because of paleontological proof of 

 paternity, but only because they looked 'simpler'. The tenet that 

 'no-one can be forefather to someone older than himself has even 

 had to be applied rather forcefully to cope with this trend in com- 

 parative anatomy. 



In the history of the vertebrates, for instance, marine animals, 

 fishes, were the earliest known, whilst later less simple forms con- 

 quered the land. But that does not mean that we have to take the 

 whale, seal and seacow as being more primitive than other mammals, 

 and relegate them to the evolutionary trend of the present-day fish. 

 This is, of course, a crude example, but the type of reasoning men- 

 tioned above really is not so very much different. In research into 

 the possible origin of life through natural causes, there is at present 

 a similar tendency. Several of the anaerobic microbes with simple 

 metabolism are taken and arranged in ascending order in primeval 

 time. But this is the same as taking the whale, seal and seacow and 

 proclaiming these to be the most ancient mammals. 



There is even no proof that our present anaerobic bacteriae are 

 that ancient at all. Quite possibly they developed much later from 

 actualistic aerobic life, just as the seagoing mammals mentioned 

 returned to the oceans long after their ancestors had made the 

 evolutionary stride from sea to land. 'Simple' is no proof either for 

 'primitive' or 'early', and arranging our present-day anaerobic bacteria 

 in such an ascending order gives the false impression that we know 

 much more about the origin of life than we actually do. 



