Plants and the insects that eat them comprise the majority of the earth's biodiversity and their interactions are extremely intense in tropical forests. The evolutionary interactions between herbivores and plants has led to an "arms race" in which innovations in plant defenses are met by counter adaptations in insects. How plant defenses shape plant evolution and interactions with insects will be studied in Inga, a widespread and diverse tropical tree in the pea family. Inga has an arsenal of toxic chemical defenses and also attracts defensive ants by producing nectar on leaves. To understand the costs and benefits of these defense strategies, and to see how they have changed over time, researchers will quantify defenses in many species of Inga from Panama, Ecuador and Peru, and will sequence DNA to create a phylogenetic tree. This is the first study to examine a range of chemical and non-chemical defenses, quantify their effectiveness and tradeoffs between defenses, and test their evolutionary relationships.
Approximately 50% of prescription medicines are still derived from nature, so improving our understanding of where and how these chemical defenses work in nature is valuable. The ecological information about plant chemical defenses has informed a drug-discovery project in Panama that emphasized economic development and conservation. Latin American students will also be involved in the field research, thus facilitating training and better access to study abroad. The capacity-building and scientific information obtained in this project have implications for forest restoration, and are consistent with goals of conservation and international biodiversity programs.
