Table of Contents
      Amphibian Neoteny 319  
      The Ecological Determinants of Progenesis 324  
            Unstable Environments     324  
            Colonization     326  
            Parasites     328  
            Male Dispersal     330  
            Progenesis as an Adaptive Response to Pressures  
              for Small Size     332  
      The Role of Heterochrony in Macroevolution: Contrasting Flex-  
          ibilities for Progenesis and Neoteny     336  
            Progenesis     336  
            Neoteny     341  
      The Social Correlates of Neoteny in Higher Vertebrates     345  
10     Retardation and Neoteny in Human Evolution 352
        The Seeds of Neoteny     352  
        The Fetalization Theory of Louis Bolk     356  
            Bolk's Data     356  
            Bolk's Interpretation     359  
            Bolk's Evolutionary Theory    361  
        A Tradition of Argument     363  
        Retardation in Human Evolution     365  
      Morphology in the Matrix of Retardation     376  
            Of Enumeration     376  
            Of Prototypes     384  
            Of Correlation     390  
        The Adaptive Significance of Retarded Development     397  
11     Epilogue 405
            Notes     413  
            Bibliography     41  
            Glossary     479  
            Index     487