Testing the evolutionary drivers of malaria parasite rhythms and their consequences for host-parasite interactions.

Undertaking certain activities at the time of day that maximises fitness is assumed to explain the evolution of circadian clocks. Organisms often use daily environmental cues such as light and food availability to set the timing of their clocks. These cues may be the environmental rhythms that ultimately determine fitness, act as proxies for the timing of less tractable ultimate drivers, or are used simply to maintain internal synchrony.

Virulence is associated with daily rhythms in the within-host replication of the malaria parasite .

Most malaria ( spp.) parasite species undergo asexual replication synchronously within the red blood cells of their vertebrate host. Rhythmicity in this intraerythrocytic developmental cycle (IDC) enables parasites to maximise exploitation of the host and align transmission activities with the time of day that mosquito vectors blood feed.

Correlates of early reproduction and apparent fitness consequences in male Soay sheep.

Life history trade-offs are ubiquitous across species and place constraints on the timing of life history events, including the optimal age at first reproduction. However, studies on lifetime breeding success of male mammals are rare due to sex-biased dispersal and the requirement for genetic paternity inferences. We studied the correlates and apparent fitness consequences of early life reproduction among males in a free-living population of Soay sheep () on St Kilda, Scotland.

Access to resources buffers against effects of current reproduction on future ability to provide care in a burying beetle.

Studies investigating the trade-off between current and future reproduction often find that increased allocation to current reproduction is associated with a reduction in the number or quality of future offspring. In species that provide parental care, this effect on future offspring may be mediated through a reduced future ability to provide care. Here, we test this idea in the burying beetle , a species in which parents shift the cost of reproduction toward future offspring and provide elaborate parental care.