David Collins

My main research interests have been on ageing processes in insects using the fruitfly, Drosophila melanogaster and the bumble bee, Bombus terrestris as model species. Ageing theory predicts (and most solitary species show) a negative relationship between fecundity and longevity because reproduction is generally thought to be costly. However, a somewhat puzzling challenge is that many social insects, including Bombus, exhibit positive relationships between fecundity and longevity. In my most recent research, I was able to experimentally increase the fecundity of bumble bee queens, causing even long-lived queens to have reduced longevity, showing that reproduction is costly in social insects after all. Furthermore I have shown the directionality of the fecundity-longevity relationship in insects is strongly influenced by the environmental circumstances of their larval development. In my experiments, larvae fed on poorer diets were more likely to exhibit a negative fecundity-longevity relationship. These findings provide a possible mechanism for why social insects appear to have a positive fecundity-longevity relationship. They suggest that the relationship is caused by brood care and nutrition quality differences provided to individual larvae in social insect colonies.

Currently, I am working on the interaction between sociality, diet, and ageing in Drosophila melanogaster. In this species, flies cohabiting with old individuals appear to age at a much faster rate than flies cohabiting with young individuals. I am isolating the mechanisms behind this interesting phenomenon, and investigating how different life extension effects (such as from diet restriction and cohabitation with young individuals) interact to maximise longevity.

Beyond these topics, I have also had research interests in the genetics of caste determination in social insects, and on the role of RNA interference in sexual conflict.

Although my primary role is currently research, I also enjoy doing as much teaching as I can. Recently I have developed an interest in teaching students advanced analytical techniques and am now running a Environmental Sciences MSc module on 'Statistics and Modelling for Scientists using R.' For this I try to help students to work through analytical problems in the Environmental Sciences using real-life data sets. My goal is to help 'de-mystify' modern statistical concepts so my students feel much more confident about using them throughout their chosen careers.

Beyond this course I also teach on modules associated with ecology, evolution, and whole-organism biology. As a keen naturalist, I especially enjoy teaching on field-based modules including the 'Ireland Field Course' module to Inch in the Republic of Ireland, and the 'Fieldwork in the Tropics' module to eSwatini, Africa. My teaching focusses on helping students to sample and identify animals and plants in the field, and on using close observations of wildlife to make inferences about macro-scale environmental processes. 

Below is a full list of modules I currently teach on:

Level 3 

• Foundation year
  

Level 4

• Biodiversity
• Skills for Biologists

Level 5

• Behavioural Ecology
• Evolutionary Biology 
• Fieldwork in the Tropics
• Ireland Field Course
• Parasites and Pathogen Ecology

Level 6

• Evolution in Health and Disease
  
• Social Evolution

Level 7

• Statistics for Scientists