Justin SH Wan
PhD Alumni
Field of Research: 
Stress adaptation, specialisation
Contact details:

Costs of adapting to extreme and novel environments

My research focuses on potential evolutionary costs to adapting to extreme, stressful and novel environments in plant species. I use a mix of experimental and modelling approaches to address the following questions:

1) What are the costs of adaptation to extreme and stressful environments?

Populations adapted to stressful environments (e.g. mine sites) tend to remain habituated in the stressful environment. When such plants are grown under non-stress conditions, they tend to have lower performance than non-stress populations. However, these differences in fitness also tend to be small or non-existent. At times, the stress tolerant genotype may even outperform the non-stress genotype! We explore the potential for consistent ‘hidden’ or conditional costs. In addition, we attempt to distinguish genetic ‘evolutionary’ costs from costs associated with resource allocation.

2) Can adaptation costs be mitigated over time?

Compensatory evolution may occur after a population adapts to a new stress - where natural selection selects against stress tolerant genotypes with high costs. This effect could improve the fitness or growth rate of the population over time. If compensatory evolution occurs, it may explain cases where costs seem low or not present. It may also explain genotypes which can adapt to both stress and non-stress environments easily.

Supervisor - Dr Stephen Bonser

Co-Supervisor - Associate Professor Angela Moles