Renee A Duckworth

Renee A Duckworth

Associate Professor, Ecology and Evolutionary Biology
Member of the Graduate Faculty
Associate Professor, BIO5 Institute
Primary Department
Contact
(520) 626-0734

Research Interest

Dr. Renee Duckworth, Ph.D. is Associate Professor of Ecology and Evolutionary Biology. The ultimate goal of her work is to understand the link between micro and macroevolutionary processes with specific focus on ecological feedbacks and evolutionary diversification. To achieve these goals, she integrates approaches from evolutionary and physiological ecology to quantitative genetic and genomic methods. Her current work uses large-scale field experiments, empirical measures of lifetime fitness and molecular multi-generational pedigree reconstruction to investigate the dynamics of trait evolution in the context of range expansion and species coexistence in passerine birds. Current projects in the lab include the evolution of adaptive introgression, the mechanisms of species coexistence at range margins, the role of adaptive maternal effects in range expansion, and the origin and evolution of animal personality traits.

Publications

Badyaev, A., & Duckworth, R. (2008). Context-dependent sexual advertisement: plasticity in development of sexual ornamentation throughout the lifetime of a passerine bird. JOURNAL OF EVOLUTIONARY BIOLOGY, 16(6), 1065-1076.

Male investment into sexual ornamentation is a reproductive decision that depends on the context of breeding and life history state. In turn, selection for state- and context-specific expression of sexual ornamentation should favour the evolution of developmental pathways that enable the flexible allocation of resources into sexual ornamentation. We studied lifelong variation in the expression and condition-dependence of a sexual ornament in relation to age and the context of breeding in male house finches (Carpodacus mexicanus) - a species that develops a new sexual ornament once a year after breeding. Throughout males' lifetime, the elaboration of ornamentation and the allocation of resources to the development of sexual ornamentation depended strongly on pairing status in the preceding breeding season - males that were single invested more resources into sexual ornamentation and changed ornamentation more than males that were paired. During the initial (post-juvenile) moult, the expression of ornamentation was closely dependent on individual condition, however the condition-dependence of ornamentation sharply decreased throughout a male's lifetime and in older males expression of sexual ornamentation was largely independent of condition during moult. Selection for early breeding favoured greater ornamentation in males that were single in the preceding seasons and the strength of this selection increased with age. On the contrary, the strength of selection on sexual ornamentation decreased with age in males that were paired in the preceding breeding season. Our results reveal strong context-dependency in investment into sexual ornamentation as well as a high flexibility in the development of sexual ornamentation throughout a male's life.

Duckworth, R. A. (2006). Aggressive behaviour affects selection on morphology by influencing settlement patterns in a passerine bird.. Proceedings. Biological sciences / The Royal Society, 273(1595), 1789-1795.

PMID: 16790412;PMCID: PMC1634784;Abstract:

The importance of behaviours as instigators or inhibitors of evolutionary change remains largely unresolved and this is in part because there are very few empirical examples of how behaviours affect evolutionary processes. By determining the environment of breeding, aggressive interactions over territories have the potential to strongly impact selection pressures experienced by individuals. Western bluebirds (Sialia mexicana) provide a unique opportunity to investigate the evolutionary importance of aggression, since their highly variable breeding habitat favours distinct foraging techniques and they also compete aggressively for nest boxes, a resource that is easy to manipulate. Here, I show experimentally that more aggressive males compete more effectively for territories with a high density of nest boxes and, as a consequence, aggressive and non-aggressive males are sorted into distinct breeding habitats that differ in the strength of selection on morphological traits. Specifically, males with longer tails and tarsi were favoured in open habitats where high agility is required to forage efficiently, whereas in forested habitats, where agility is less important, selection was weak. These results show that aggression can affect selection on a local scale by determining individual settlement patterns. More generally, because territorial interactions are important across a wide variety of taxa, these results suggest that aggressive behaviour has the potential to impact the evolutionary trajectory of many animal populations.