Sexual dimorphism of the pelvic architecture: A struggling response to destructive and parsimonious forces by natural & mate selection

INTRODUCTION Sexual dimorphism of the human pelvis is linked intimately with its adaptive functions. The peculiarly shaped hominid pelvis represents the total response to the diverse forces that have moulded its structure. These diverse forces are requirements for efficient bipedalism and parturition. In some respects, the structural demands of these unrelated functions have been in conflict. The morphological response to the dominant requirement, bipedalism, is clearly discernible, while the changes serving the needs of parturition are seen as compensatory modifications as reflected with greater emphasis for pelvic sexual dimorphism in the female. In addition, sexual selection has made sexual dimorphism even more pronounced. The female buttocks have undergone sexual elaboration through mate choice by males. Thus, total pelvic architecture is a mosaic constituted of the aggregate of differential responses to different functional goals. There are complications during parturition that have been repeatedly prevented or interceded by medical technology, close monitoring, surgical practices such as caesarian sections, and other strategies. With these complications, one could hypothesize that these natural operators, which have exerted their influence since the beginning of mankind, might be becoming increasingly destabilized, attenuated or stochastic.