Kelly Tarlton's Scholarship

Ed Abdool
School of Biological Sciences, Victoria University of Wellington

Mathematical Modelling of Productivity and Biomass Along a Latitudinal Gradient in the Ross Sea
 
Each year, an area of sea ice more than twice the size of Australia forms in Antarctic during winter and melts in summer. This ice provides a unique habitat for spectacular growth of micro-organisms (bacteria, algae, and phytoplankton). They are the “grass of the sea”: these organisms provide the energy base of the food web by fixing essential elements and recycling nutrients for consumption by other organisms. The microbial community is the most diverse form of life in Antarctica, but we still do not understand how they support local ecosystems. Furthermore, about 99% of them are un-described and will remain so if traditional methods to catalogue them are employed.
 
I will link physical, geographic and biological data into a mathematical model of population dynamics that will summarise the biodiversity at each site, both temporally and geographically.  The model will take advantage of satellite technology to relate climate conditions, ice thickness and snow cover, and chlorophyll concentrations to the state of health of the population at the time of sampling.

Angela McGaughran
Allan Wilson Centre for Molecular Ecology and Evolution, Massey University

Determining Unique Genetic, Co-Evolutionary and Metabolic Patters/Rates that Previal in Polar Environments

My PhD is centred around deciphering the unique evolutionary patterns that prevail in polar environments.  One aspect of my project will be to test springtail and mite samples for the presence of endosymbiotic bacteria such as Wolbachia, Rickettsia and Spiroplasma, which has not been done before in Antarctic species.  If I find evidence for co-existence of these different bacterial types within mite and springtail species, then I will be able to produce a co-phylogeny. 

Additionally, to adequately interpret evolutionary history, we must understand the evolutionary rates of the organisms of study, particularly in the cold where unique constraints on life evoke distinctive adaptive mechanisms.  For example, biotic factors such as life cycle length, organism activity and metabolic rates are thought to potentially affect DNA mutation rates and it is thought that low environmental temperatures in polar regions tend to lengthen life cycle (due to a short annual growing season).  This, in turn, would reduce overall activity and potentially slow rates of molecular evolution (e.g. through a reduced mutation rate).  There are many conflicting results on this theory, so my work will attempt to resolve this issue through investigation of variation in activity (energetic budgets), along a latitudinal gradient, by coupling behavioural observations with measurements of in situ microclimate parameters and respiration/metabolic rates at selected Antarctic sites.