On homology

The currently most widely used definitions of homology, which concentrate exclusively on what I call phylogenetic homology, involve comparisons between taxa. Although they share important conceptual relationships with phylogenetic homology and their role in evolutionary biology is significant, serial and other forms of iterative homology have been, by comparison, overlooked. There is need for a more inclusive definition of homology. I propose that the basis of homology in the broad sense is the sharing of pathways of development, which are controlled by genealogically-related genes. Using this definition, one can construct hierarchies of homology, and recognize different degrees or strengths of homology. Because different aspects of structures are controlled by distinct developmental programs, it is sometimes necessary to speak of homologies of different attributes of specific structures, rather than to homologize the structures per se. For good biological reasons, parallelism may be difficult to distinguish from homology, and one must in practice be willing to tolerate some ambiguity between them. The formulation I present leads to some unorthodox conclusions about homology in mammalian dentitions and homology between the fore-and hindlimbs of tetrapods.     

On Reflexivity

The value of reflexivity has been widely accepted in anthropology during the past two decades. The concept of ref lexivity can be seen developing in the work of theorists and ethnographers of the 1960s and 1970s and was brought to flower among theorists and ethnographers of the 1980s and 1990s. But little critical analytic attention has been directed toward its claims to generate new understandings and inform about their positional foundations. However, consideration of the possibility of reliable self-reports leads to skepticism rather than confidence. Furthermore, the underlying assumption that the unavoidable subjectivity of researchers negates any external validation of knowledge proves to be mistaken, making the question of positionality moot. [Keywords: reflexivity, postmodernism, ethnography, positionality, scientific method]