U FOREWORD 



J^ It can scarcely be denied that the development of the brain is a central, 

 even a determining, aspect of human evolution. For, as we learn more about 

 this process, it becomes increasingly evident that the changes leading to 

 Homo sapiens are intimately linked in a kind of feedback situation with the 

 brain. Even if we knew nothing else about it, its threefold increase in size 

 during hominid evolution would merit, if not demand, a special interest. 

 And yet this is one of the least known of the adaptive changes that have 

 occurred in human evolution. 



One obvious reason, but not the only one, for this is that the brain does 

 not fossilize and thereby provides us, as do the bony and dental structures, 

 with an anatomical record that would enable us to trace in some detail its 

 development. All that we do have in the way of fossil evidence is the inner 

 surface molding and the capacity of the braincase. And the latter can be 

 inferred by indirect methods only for the many cases where the fossil 

 specimen is fragmentary. 



But because our evidence is so limited, what we do have, or can reason- 

 ably be inferred, takes on an enhanced importance, and it is essential that 

 it be properly and meticulously assembled and appraised. For much can be 

 learned and certain deductions of great importance may be drawn from 

 such data. This necessary task has been admirably carried out by Professor 

 Tobias in his James Arthur Lecture, now expanded in the following book. 

 His broad experience with hominid fossil material has richly equipped him 

 for this task. We are all deeply indebted to him for this valuable survey, 

 long overdue, which I predict will be a standard reference for a long time. 



Harry L. Shapiro 



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