Selective Breeding for an Infantile Phenotype (Isolation Calling)

Abstract

Since its origin more than 30 years ago, developmental psychobiology has had as its central focus the role of early experience in the development of behavior and physiology. Genetically heterogeneous strains have generally been used in order to assure that any effects of experimentally altered early environments would not be likely to depend upon a unique genetic contribution. There were early interests in genetic effects, however, and in some instances, specific inbred strains were used in order to study environmental effects on a particular vulnerability or predisposition. It did not take researchers long to realize that the early environment of most mammals and birds consists of a complex and changing interaction with its parents and siblings. To better understand the mysteries of the prenatal and preweaning environments, an array of novel methods and approaches have been created that continue to be effectively used by researchers in developmental psychobiology. Yet this focus has come at a cost. There have been few cross-disciplinary efforts with the field of behavior genetics. This emphasis on environmental over genetic contributions to development over the last decades could perhaps have been justified on the grounds that the early genetic contribution could not be as readily described mechanistically or varied experimentally. In the past few years this picture has changed radically and so has the biological orientation toward genetic determinism. Development can now be studied by manipulating identified genes with known cellular effects at specific stages of development.