Allocation, life history and senescence: an integrated approach

University Of South Carolina At Columbia, Columbia SC

Investigators

Abstract

Animal life history traits include survival, dispersal and reproduction, all of which change with age. These life history traits depend on food intake and on allocation of that food to body maintenance, activity and making offspring. Variation in the amount of food eaten can affect nutrient allocation among these traits, changing age at death, activity patterns, and timing, numbers and quality of offspring. Likewise, increased demands for allocation to activity can reduce allocation to other traits. Feeding and allocation patterns also affect trait senescence, or loss of function with age. How the set of life history traits changes with food stress or with activity stress is not well understood. Using an insect test system, this work will examine how such environmental stresses alter life history traits, using both laboratory physiological experiments and field observations. Techniques will include stable isotope analysis, insect respirometry, micro-analysis of chemical composition of eggs and measurements of body morphology. This work will contribute to understanding the impacts of environmental change on organisms' survival and reproduction. To do this, the work will connect experimental laboratory results with field observations, to build an understanding of how life history traits respond to environmental variation in the wild, and of trait senescence in the wild. The work will also test the theory of nutrient allocation as the basis for life history trade-offs. The project will include mentoring of undergraduates, women and minorities in research. Research results will be used in teaching, and teaching ideas will be published for use by others. The work builds on extensive field databases at a field station. Educational outreach associated with the project will also be directed to the general public. Outreach will include a continuing studies course, work with a public education program, development of museum exhibit materials, talks for community groups and radio shows, and newspaper articles. Journalists will participate, both to learn about the project and in turn to educate students and scientists on communication with the press and the public.