Researchers: Dr. Sabrina Amador (STRI) and Dr. Armando Castillo (INDICASAT-AIP)
Evolutionary transitions often involve morphological and behavioral changes. While external morphological changes associated with the evolution of new traits are well known, changes at the level of internal anatomy remain less studied. Insects' internal organs are fascinating because their exoskeleton can impose constraints on the contents of the head capsule.
In this project, we aim to understand the internal structural changes associated with the transition of Pseudomyrmex ants from arboreal, omnivorous habits to an obligatory mutualism with plants. In the Pseudomyrmex-Vachellia (formerly Acacia) mutualism, the plant provides food and nesting sites, significantly reducing the need for navigation outside the plant. Additionally, worker ants expand their defense beyond the colony, patrolling the plant and communicating potential threats to nestmates via alarm pheromones. The behavioral changes related to mutualism have consequences for the organs inside the head capsule that have yet to be explored.
Advances in confocal microscopy allow us to examine changes in internal anatomy within an evolutionary context, overcoming the challenges of dissecting organs and observing them in isolation. This project utilizes images to compare the internal head morphology of workers and queens of a plant-mutualistic species (P. spinicola) with an omnivorous species that nests in twigs (P. boopis). In addition to the material we already have, we seek to generate new information on changes in various sensory organs (eyes, antennae, etc.) involved in the transition to obligatory mutualism, as well as detailed modifications in glands, muscles, and the brain.
The intern will:
- Learn about internal anatomy, ecology, and ant biology.
- Gain experience with confocal microscopy techniques.
- Learn how to generate 3D models from photo sequences.
- Explore semi-automated segmentation techniques using neural networks and deep learning (which may require writing or managing Python code).
- Develop scientific writing skills for research articles.
This project has minimal fieldwork components; most of the time will be spent using the microscope and working on a computer. Although the general idea is already outlined, there is room for modifications and further examination of various structures. Therefore, we expect the intern to actively engage in reasoning and planning their thesis project, reading literature, researching methods to accelerate measurements, and committing to participating in the STRI community and laboratory activities.
