Presenters: Jessica Jones, College of Science, Biology
Authors: H. Adams, T. Allgaier, E. Duke, A. Jackson, J. Jones, G. Matthews, C. Shirts, R. Soni, J. Wasden, P. Dunn
Faculty Advisor: Paul Dunn, College of Science, Biology
Institution: Utah Valley University
Many organisms exhibit a “bathtub-shaped” mortality curve, with high mortality risk early in life that decreases until maturity (ontogenescence) followed by increasing risk with age (senescence). Ontogenescence has been observed in organisms with very different life history strategies, from barnacles to humans, even though the disadvantages of dying before reproduction should be strongly selected against. One possible explanation for ontogenescence is the Transitional Timing Hypothesis, which states that increases in mortality are associated with transitional events like hatching that are concentrated early in life cycles. Previous studies on the timing of early-life mortality have focused on drastic events (i.e., hatching and metamorphosis). The goal of this study is to look at the potential mortality risks of less drastic transitions such as molting events using Artemia (brine shrimp), a model organism with a well-understood life history. Individual brine shrimp are hatched from cysts and monitored through their development until maturation. The timing of molts and deaths are recorded and analyzed for links. Pilot experiments for determining the ideal culturing conditions that will allow for the collection of individual-level data are ongoing. The proportion of individuals that survive to maturity has increased from 0 in early trials to 0.25 in the most recent trials.