Does mother know best? Unifying proximate causation and ultimate explanation in mammalian sex allocation. The study of parental effects is a fundamental area in evolutionary ecology, but is characterised by poor integration of theory (ultimate causation) and physiology (proximate causation). This is true in sex allocation research that focuses almost exclusively on ultimate causation without integrating the physiological mechanisms for sex ratio adjustment. Using a combination of experiments and ....Does mother know best? Unifying proximate causation and ultimate explanation in mammalian sex allocation. The study of parental effects is a fundamental area in evolutionary ecology, but is characterised by poor integration of theory (ultimate causation) and physiology (proximate causation). This is true in sex allocation research that focuses almost exclusively on ultimate causation without integrating the physiological mechanisms for sex ratio adjustment. Using a combination of experiments and modelling, the project addresses this gap in understanding mammalian sex allocation, specifically: the lack of known mechanism; the connection between proximate mechanistic explanation and adaptive fitness explanations; and, knowledge on constraints. This project argues that one mechanism, pre-implantation glucose levels, links adaptive hypotheses with proximate causation. Read moreRead less