Abstract Dietary restriction is renowned as the most consistent environmental intervention to extend lifespan and delay ageing. Typically this effect is thought to result
Dietary restriction is renowned as the most consistent environmental intervention to extend lifespan and delay ageing. Typically this effect is thought to result from a reduction in the availability of calories and a subsequent switch from investment in reproduction to investment in survival under conditions of poor resource availability. However, recent work has questioned the generality of the effect of DR, demonstrating a stronger effect in laboratory adapted than non-adapted populations and a stronger effect in females than males. In addition the role of calories has been questioned, with experiments using a broader range of diets suggesting variation in the ratio of macronutrients is more important in determining lifespan, with high protein diets resulting in lower lifespan. I will present early results from an investigation of the role of calories and macronutrient ratio in determining survival and reproduction in a wild derived population of freshwater fish, the stickleback Gasterosteus aculeatus. In this study, we reared fish on one of 15 diet treatments varying in both protein to lipid ratio (P:L) and availability to allow separation of the effects of macronutrients and calories. Results suggest that P:L is more important in determining survival and reproduction than calories. In general males and females invested more in reproduction with increasing protein ingestion, but there was variation between traits and the amount of lipid ingested was also important for female reproduction. In addition, there appears to be a sex difference in the effect of diet on lifespan. Males reared on high P:L diets suffered higher mortality than those reared on lower P:L, but this does not appear to be true for females. I will discuss these results in the light of recent work assessing the importance of calories and macronutrients in determining survival and reproduction and the evolutionary explanation for the existence of sex differences in the effect of DR.
Craig Walling is an evolutionary ecologist working in the Institute of Evolutionary Biology at the University of Edinburgh. His research group focuses on understanding the evolution of, and maintenance of variation in, life history traits. Strong selection is predicted to reduce levels of genetic variation in such traits, yet genetic variation is often observed. My research aims to try and understand the causes and consequences of this variation. To address these aims I use techniques from both quantitative genetics and behavioural ecology in order to improve our understanding of both the genetic and environmental causes of variation in life history traits.
If anyone would like to meet with Craig please contact Nathan Bailey.
(Tuesday) 1:00 pm - 2:00 pm
Ellen Garland & Christian Rutzecg5@st-andrews.ac.uk, firstname.lastname@example.org Dyers Brae, University of St Andrews, St Andrews, Fife, KY16 9TH, UK