Meeting Abstract

P1.85  Tuesday, Jan. 4  Oxygen transport: a physiological integrator of phenotypic variation and life-histories? WILLIAMS, T.D.; Simon Fraser Univ., Burnaby tdwillia@sfu.ca

Evolutionary studies of variation in life-time fitness clearly show that a few high-quality (HQ) individuals contribute the vast majority of the offspring (or genes) to the next generation. For each life-history trait or component of reproductive effort these HQ individuals appear to get every reproductive decision ‘right’, e.g. they lay more, larger eggs at the optimum laying date, rear the most, high quality chicks to fledging with the highest probability of recruiting, and therefore maximise current reproductive effort, while also having the highest survival and future fecundity (counter to the idea of these life stages trading-off). The phenotypic attributes that confer ‘high-quality’ on some individuals, which is then apparent throughout all stages of their lifetime, remain very poorly understood particularly from a physiological (mechanistic) perspective. Here I suggest that components of the oxygen transport system (e.g. haematocrit, haemoglobin) might represent a physiological integrator of phenotypic variation and life-histories that contributes to repeatable individual variation in ‘quality’. Although oxygen transport has been the focus of physiological studies of optimality (e.g. symmorphosis) this concept does not appear to have been widely considered as an explanation for variation in individual quality or phenotype. However, individual variation in haematology is marked and (potentially) functionally significant during many life stages. I will illustrate this with examples including embryo development, nestling rearing environment and offspring phenotype, and costs of reproduction and carry-over effects in adult birds.