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 used flow cytometry together with ROS-sensitive fluorogenic probes to measure ROS in lizard blood cells. We measured basal levels of (i) non-specific ROS (superoxide, singlet oxygen, H 2 O 2 and peroxynitrite), (ii) superoxide specifically and (iii) superoxide after CCCP treatment, which elevated ROS production in the mitochondria. The cumulative level of nonspecific ROS was higher in adults than juveniles and superoxide level showed high heritability and variability among families. We suggest 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.

Sex ratio evolution relies on genetic variation in either the phenotypic traits that influence sex ratios or sex-determining mechanisms. However, consistent variation among females in offspring sex ratio is rarely investigated. Here, we show that female painted dragons (Ctenophorus pictus) have highly repeatable sex ratios among clutches within years. A consistent effect of female identity could represent stable phenotypic differences among females or genetic variation in sex-determining mechanisms. Sex ratios were not correlated with female size, body condition or coloration. Furthermore, sex ratios were not influenced by incubation temperature. However, the variation among females resulted in female-biased mean population sex ratios at hatching both within and among years.

Between 2000 and 2002 two populations of the spotted-tailed quoll (Dasyurus maculatus) were studied on the New England Tablelands using trapping surveys and radio-tracking. Overall, 85 individuals were trapped, but only two individuals were trapped throughout the 26 months of the study. Trapping was male-biased (74%). Adult males (>1 year) were substantially larger than females. On average, males travelled longer distances than females, and the maximum distances recorded were 8.1 and 3.9 km for a male and female respectively. Home ranges of males overlapped substantially, whereas those of females appeared to be exclusive. Mortality rates and the turnover in the quoll populations appeared to be substantial and at the beginning of autumn the populations comprised ~50% juveniles.