Testing the Evolutionary Basis of the Longevity Response to Dietary Restriction.
Funded by the Leverhulme Trust
Lifespan and ageing are extremely variable traits, and understanding the causes of this variation is one of the great challenges in biology. This research area is particularly timely given today’s rapidly ageing human populations. Dietary restriction, a reduction in the intake of food or particular macronutrients, extends lifespan and delays ageing across a diverse range of organisms. This has generated considerable interest in using dietary restriction to understand variation in lifespan and ageing, and to develop interventions to delay ageing in humans. However, we know little about why the dietary restriction response evolved, or whether it varies across genotypes, traits, or environments. Understanding this variation is essential. If dietary restriction is detrimental in some genotypes or environments, this would lead to serious doubts about; (A). Applying dietary restriction to delay ageing in humans; and (B). How generally insights from dietary restriction research can be applied. In this project we will test the evolutionary theories of dietary restriction, and quantify both genetic and environmental variation in the response.
Genetic and environmental variation in the effect of dietary restriction on life-history trade-offs and ageing in Drosophila
Funded by the BBSRC Eastbio DTP
Over the years, several studies have shown that there is some variation in the response to dietary restriction. Furthermore, a recent evolutionary hypothesis has been proposed (Adler and Bonduriansky, 2014), which suggests that the classical response of dietary restriction, namely reduced reproduction with longer lifespan, may be a laboratory artifact. This project is set to disentangle some of the possible causes of variation in this response, including adding a stressor (such as infection) to experiments measuring life history variables and ageing. This project is using the study system of fruit flies (Drosophila melanogaster).
The Causes and Consequences of Life History Variation in Natural Populations.
This projects uses the long-term study of Red deer on the Isle of Rum. Using over 40 years of data on life history traits, and a pedigree of the population, allows us to estimate the amount of genetic and environmental variation for key life history traits and thus try to predict their response to selection. Current work is investigating the role of inbreeding and inbreeding depression in the evolution of the mating system, and the role of maternal effects and their genetic basis in determining the response to selection of key early life traits such as birth weight and birth date.
Exploring the Effects of Dietary Restriction and Macronutrient Composition on Life History Traits, in a Non-Model Vertebrate System.
Funded by the BBSRC Eastbio DTP - PhD Project (2013 – 2018)
Dietary restriction (DR), is a reduction in food intake, either through overall calorie or specific macronutrient intake, while avoiding malnutrition. DR has been consistently shown to increase longevity and protect against age related diseases. Although originally thought to be the result of a reduction in caloric intake, recent evidence suggests that macronutrient intake, particularly intake of protein, also plays a role. The broad range of species in which DR is known to be effective, suggests an evolutionary conserved mechanism. However, the suggestion of a strong model species bias and a potential sex bias have led some to question the ubiquity of responses to DR. Using a non-model vertebrate system, the three-spine stickleback (Gasterosteus aculeatus), this project looked at the following questions: (i) Does caloric intake or macronutrient intake underpin changes in lifespan and reproduction? (ii) How does changing macronutrient intake impact fitness related traits, such as condition and performance? (iii) How does varying macronutrient intake effect both growth and body composition? This project also used cross-species meta-analytic techniques to explore the consistency of the effect of DR on reproduction?
The Evolution of female mating preferences: quantifying the benefits.
Funded by the Natural Environment Research Council (2011 – 2015)
There is much theoretical and empirical debate about the potential for females to gain indirect genetic benefits for offspring from mate choice. Recent studies have highlighted two potential routes, good genes benefits and compatible genes benefits. With good genes benefits, the genes an offspring inherits from its father improve fitness irrespective of the genes inherited from its mother (additive gene action). With compatible genes benefits, the effect of genes inherited from the father depend on the genes inherited from the mother (non-additive gene action). This projected investigated the relative importance of indirect genetic benefits to female mate choice using a series of behavioural and quantitative genetic experiments in the stickleback, Gasterosteus aculeatus. Quantitative genetic experiments were used to estimate the relative magnitude of additive and non-additive genetic variation for fitness related traits including survival and measures of reproductive investment. These parameters determine the potential genetic benefits to female mate choice and allow comparison of the potential for good and compatible genes benefits to mate choice.