About 300 million years prior to the origin of flowering plants, ancestors of mosses were colonizing land and creating the groundwork for the radiation of land plants. Around the same time, microarthropod (insects) inhabitants of mosses appeared in the fossil record. Thus, mosses and microarthropods potentially represent the earliest plant-insect mutualisms, and we propose to test the hypothesis that both of these partners gain fitness benefits when they interact. The PIs will test whether insects move moss sperm to other mosses, akin to the way a bee moves pollen from flower to flower. The PIs will also test whether the insects benefit by having places to lay their eggs that are safe from predators. The PIs will also determine whether there is a food ?reward? provided by the mosses for the insects. These questions will be addressed using integrated ecological, molecular genetics, and physiological approaches.
Understanding the fitness consequences of this non-angiosperm ?pollination? system will greatly broaden our knowledge of the diversity of pollinator interactions and mutualisms in the early history of life. Additionally, the project will be used as a tool for teaching ecology, the scientific method, and organism life cycles to students in Portland Public Schools. Middle school students will collect moss from local populations and grow plants through the alternation of generations. Similarly, students will rear microarthropods through the insect life cycle. Data gathered by students will be used in the classroom as a tool to explore data analysis and hypothesis testing.