I am interested in the interplay between ecological and evolutionary processes, specifically in the interaction between insects and their parasites or pathogens. A large part of my work uses Drosophila melanogaster and its parasitoids (mostly the braconid Asobara tabida) or pathogens (the entomopathogenic fungus Beauveria bassiana and the microsporidian Tubulinosema kingi) and focuses on the (co)evolution of resistance and counter-resistance.
When Drosophila larvae are attacked by a parasitoid, they can mount a cellular immune reaction against the parasitoid egg which begins with haemocytes aggregating around the egg and, if successful, ends with a melanised (and dead) parasitoid egg. In the field, there is a large amount of genetic variation in the strength of this immune reaction, both between and within populations. One explanation for the existence of so much genetic variation is that resistance is costly. Using artificial selection, we could show that indeed resistance against parasitoids has a cost. Resistance against fungal pathogens is mainly due to a battery of anti-microbial peptides, while the mechanism of resistance against microsporidia is very poorly understood. In both cases, using an experimental evolution approach, we have shown that increased resistance against these pathogens also bears costs.
Additional research interests
I am also interested in exploring what digital organisms can tell us about evolution. After all, all of life on earth essentially represents a sample size of 1. Until we find a way to quickly travel to other planets in search of life, artificial life may be the only way to explore what characteristics might be inherent to life in general as opposed to DNA-based life on earth. I use the TIERRA virtual ecosystem to investigate host-parasite coevolution in digital organisms.
In a completely different field, I am using phylogenetic tools to try and answer the age-old question as to where the game of chess originated: India, China, or somewhere else altogether? Board game rules are not static, but evolve over time as people introduce rule changes. If the game with the new rules increases in popularity, it may drive the old version of the game extinct.
Bethany Shaw: Chronophysiology of Spotted Wing Drosophila, AHDB Horticulture
Affiliate research group(s)
Institute for Life Sciences (IfLS),Institute for Complex Systems Simulation (ICSS)
Investigating the effect of nutrition on immunity, using Drosophila melanogaster, its parasites and its pathogens as a model system.
We study Predictive Adaptive Responses (PARs), using Drosophila melanogaster as a model system, and focusing on diet composition.
Computational methods can shed light on evolutionary processes in a way which is not feasible using actual living organsisms.
Bacteria often occur in structured communities in nature, called biofilms, in which they form microcolonies.
Comparison of genome-wide gene expression of parasitised and unparasitised larvae focuses on genes which play a role in the actual immune response.
This project employs phylogenetic techniques to investigate the origin and subsequent evolution of chess and chess-like board games.
Knowing exactly how the nervous system degenerates and becomes more vulnerable with age would further our understanding of how ageing occurs and how to prevent the debilitating neurological effects of ageing.
Predictive adaptive responses (PARs) are long-term phenotypic plastic responses, made during development in anticipation of the future adult environment.
Dr Lex Kraaijeveld
Faculty of Natural & Environmental Sciences
Life Sciences Building 85
University of Southampton
Telephone:(023) 8059 3436