Meeting Abstract

S5-1.5  Saturday, Jan. 5  From emergence to evolution: Phenotypic integration of complex offspring sex-bias BADYAEV, A.V.; Univ. Arizona abadyaev@email.arizona.edu

Sex-bias in egg-laying order is a seemingly evolutionary impossible combination of precision, complexity, context-dependency, and reversibility. Yet, it is a common occurrence and a frequent starting point for a wide range of adaptive ecological and evolutionary phenomena – from the onset of behavioral strategies to the speed of acquisition of morphological adaptations. Such adaptive sex-bias is unlikely to be a product of coordinated genetic evolution of multiple players in the processes of egg production and sex-determination as this requires unrealistic expectations of evolutionary rates and population sizes and is not a desirable outcome for the process that needs to retain substantial environmental sensitivity. Recurrent deployment of conserved hormonal regulators throughout oogenesis can overcome some of these constraints, but introduces new ones – the necessity to reconcile general effects of hormonal regulation with required directionality and precision during particular stages. I will examine whether self-regulatory and emergent processes that govern the dynamics of oogenesis can produce non-random coordination of oocyte growth, ovulation order, and sex-determination under routine perturbations of shared physiological mechanisms, thereby significantly simplifying the evolutionary pathway to complex, precise, and reversible adaptations in sex-bias.