---

Sexual selection, through the processes of mate choice and competition for mates, is a powerful force that is responsible for the evolution of spectacular species’ characteristics such as elaborate plumage and songs in birds, deer antlers and fish colouration. Sexual selection can vary in space, within a species’ geographical distribution, and thus can cause morphological and behavioural differentiation among populations of the same species. It can also affect population viability and genetic variation, and thus may impact on species’ ability to survive current rapid environmental changes and to adapt to new conditions. Understanding how sexual selection varies in space, and its effects on species’ responses to environmental changes, is therefore important as it will help understanding how it might impact species’ persistence in rapidly changing environments. In this project, with the aid of computer simulations, Max is developing new theory to understand how sexual selection operates in complex and changing environments.

---

Dispersal and mating system are fundamental for species’ survival. They determine how genes are transmitted across generations and in space, and genetic variation ultimately determines a species’ potential to adapt to new conditions. Dispersal and mating system are tightly interconnected. Female multiple mating, in particular, is now being shown to be widespread across organisms and to have far-reaching consequences for species evolution and potentially for species’ responses to environmental changes. As with dispersal, female multiple mating is thought to evolve as a consequence of inbreeding. However, we still do not know how these two behaviours affect each other’s evolution, how environmental changes impact their joint evolution and what this means for species’ persistence. Lana is investigating these questions using a model species for the study of mating system and dispersal, the seed beetle, Callosobruchus maculatus.

---

Inbreeding mating systems, where individuals mate regularly with close relatives and thus are permanently inbred, have evolved multiple times in both animal and plants. Yet, they represent an intriguing evolutionary puzzle. Because of the costs associated with inbreeding (inbreeding depression and loss of genetic diversity), we expect strong selection for mechanisms that allow avoiding inbreeding. However, in situations where the costs of avoiding inbreeding are greater than the cost of inbreeding itself, for example because of extremely high cost of dispersal, tolerance to inbreeding might evolve. Additionally, the transition to permanent inbreeding requires purging of most of the inbreeding load, an even greater challenge for self-incompatible organisms. The mechanisms behind the transition to inbreeding mating systems becomes even more intriguing when it is associated with a transition to sociality, as in social spiders. Thus, evolution of inbreeding mating systems represents a fascinating example of eco-evolutionary interactions between dispersal, mating system and sociality, still waiting for theory explaining their occurrence. Anders is developing new theory to understand (1) evolution of inbreeding mating systems and associated sociality, and (2) its consequences for species adaptation to changing environments and evolutionary potential.

---

The impact of climate change and human-induced habitat fragmentation has resulted in an unprecedented planet-wide biodiversity crisis. Thus, it is crucial to understand the conditions which influence the survival of vulnerable individuals. Stress is associated with an increased risk of mortality, and there is considerable evidence of a link between maternal stress during pregnancy and early-life mortality in offspring. Accumulating evidence indicates that the developing foetus responds to conditions experienced by the mother, and that exposure to stress may have life-limiting effects. The objective of Connie’s project is to examine the association of maternal stress with juvenile behaviour and mortality in the fallow deer. Connie will collect behavioural and environmental data a wild herd of fallow deer Dama dama resident in Phoenix Park, Dublin, to estimate the extent to which maternal stress during foetal development predicts fawn survival.