ABSTRACT PI: Brodie Proposal Number: 9600775 CAREER Award: Inheritance and Maternal Effects of Parental Care Behavior Evolution is necessarily a genetic process. While much insight into behavioral ecology has been made without consideration of patterns of inheritance, there is much to be gained from a genetic perspective. In particular, parental care behavior is a category of trait that is likely to have complex effects on offspring characters and fitness, and thereby on the evolutionary process. Understanding the importance and origin of parental care in species as diverse as insects and humans depends on a knowledge of the underlying genetics of the behavior. Mothers and other relatives often influence the expression of traits in offspring through the care they provide. The importance of these so-called 'non- genetic maternal effects' in determining offspring traits is well known. However, maternal effects have generally been considered evolutionarily uninteresting, because only genetic components of traits respond to natural selection. In the last 5-10 years, theoretical advances have changed this view, suggesting that non-genetic maternal effects can drive evolution. Because many maternal effects are thought to stem from parental care behavior, this new body of theory suggests that the evolutionary origins and consequences of behavior may be more complex than previously imagined. Despite these exciting implications, maternal effects of behavior have rarely been studied in natural systems. Strawberry arrow poison frogs (Dendrobates pumilio) present a unique and fascinating system in which to quantify parental care behavior and its effect on offspring characters. Male frogs attract females to a territory, where 3-6 eggs are laid on land. For the next 10-15 days, the male guards and periodically waters the eggs until tadpoles emerge. The female then returns and individually transports ea ch tadpole to a separate rearing site, usually a water-filled plant axil. For the next 3 months, the female visits each tadpole every few days, and lays unfertilized eggs for her offspring to eat. Tadpoles have specialized mouth parts and can only eat eggs. This specialized parental care lends itself to simple quantification. D. pumilio are easily bred and raised in captivity. The proposed work combines studies of inheritance and maternal effects under captive conditions with studies of fitness consequences of parental care in nature to address the evolutionary consequences of parental care behavior. Complex breeding designs that include cross- fostering offspring among unrelated parents will be used to quantify the maternal effect of both male and female parental care on offspring traits including development and morphology. Two generations of frogs will reared in the laboratory so that the inheritance of parental care behavior itself can be understood. A separate field project will investigate how paternal and maternal care influence offspring phenotypes and survival under natural conditions. The three phases of this study - inheritance, maternal effects and fitness consequences - will combine to offer new insight into the evolution of parental care. The proposed research will generate and maintain a large captive colony of strawberry arrow poison frogs at the University of Kentucky that will be a valuable resource for formal undergraduate education and public outreach. A small walk-in rainforest room will be constructed to generate a hands-on learning experience. The frog colony also will be used in exercises incorporated into several large upper level courses. The use of this colony in undergraduate classes will also provide a direct example of the kinds of biodiversity present in tropical rainforests to students who would otherwise never be exposed. Additionally, undergraduate students will be heavily involved at all levels of this research. A number of undergraduates will be employed by this project to assist with data collection and colony maintenance. Regular laboratory meetings will involve students at every step of work, so that they experience the full process of science from the generation of hypotheses to the design and execution of experiments to the tedium of behavioral data collection.The Dendrobates colony also provides a rare opportunity for undergraduates to conduct independent research on behavior.
