biological sciences HONOURs 2014 - The University of Sydney

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REPTILE EVOLUTION AND
BEHAVIOURAL ECOLOGY
Research Interests
We research broad, evolutionary biology, most often using
reptiles and amphibians as models.
Honours projects
Honours projects can be tailored to the student’s interest in the
following areas:
1. Multiple paternity in a changing climate. A changing climate
is expected to have profound effects on many aspects of
ectotherm biology. We assess year-to-year variation in sexual
selection on body size and post-copulatory sperm competition
and cryptic female choice. Elevated temperature is expected
to increase mating rate and number of sires per clutch with
positive effects on offspring fitness. We investigate if years
when the ‘quality’ of a female’s partners is more variable (in
standard errors of a male sexual ornament) show less multiple
paternity. This would agree with prior laboratory trials in which
females exercised stronger cryptic female choice when male
quality varied more.
An increased number of sires contributing to within-clutch
paternity may decrease the risk of having malformed offspring.
Ultimately, such variation may contribute to highly dynamic and
Professor Mats
Olsson
Room 416, Heydon-
Laurence Building A08
T: (02) 9351 2697
E: mats.olsson@sydney.
edu.au
shifting selection mosaics in the wild, with potential implications for the evolutionary ecology of
mating systems and population responses to rapidly changing environmental conditions.
2. Evolution of Reactive Oxygen Species dynamics. In the ageing individual, the production of
Reactive Oxygen Species (ROS) accelerates with cell senescence. Depending on the heritability
of the underlying processes that determine net ROS levels, this may influence ageing per se
and its evolutionary direction and rate of change. In order to understand the inheritance and
evolution of net ROS levels in free-ranging lizards, we use flow cytometry together with ROSsensitive
fluorogenic probes to measure ROS in lizard blood cells.
We measure basal levels of (i) unspecific ROS (superoxide, singlet oxygen, H 2
O 2
and
peroxynitrite), and (ii) superoxide specifically. The cumulative level of unspecific ROS is higher in
adults than juveniles and superoxide level showed high heritability and variability among families.
We suggest, and design future studies, around the fact that the evolution of ROS dynamics
may be ROS species-specific and perhaps depend on the relative degree of uni- or biparental
inheritance of ROS main regulatory pathways.
Right: Crab spider by Claire MacAlpine (Honours student 2013)
supervised by Dieter Hochuli (pg 25) and Shawn Wilder (pg 50)