Evolution in isolation: genetic structure of an insular population of Epidendrum fulgens (Orchidaceae)

• Grant number: 22/09026-1
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: January 01, 2023
• End date: December 31, 2025
• Field of knowledge: Biological Sciences - Ecology
• Principal Investigator: Fábio Pinheiro
• Grantee: Beatriz Christine de Marco Pereira
• Host Institution: Instituto de Biologia (IB). Universidade Estadual de Campinas (UNICAMP). Campinas , SP, Brazil

Abstract

Due to their high degree of isolation and different environmental conditions, insular organisms can exhibit a marked decline in genetic diversity, as well as changes in the reproductive system when compared to conspecific continental populations, such as higher levels of self-fertilization and clonal reproduction. Alcatrazes Island has been an important site for the study of evolution, as it is a highly isolated environment that does not receive human intervention. Among the species found on the island, we highlight Epidendrum fulgens, a plant that has a wide distribution in restinga environments on the mainland, and which is also found in rocky outcrops on Alcatrazes Island. The main objectives of this study are: 1 - to investigate how the habitat restriction of the insular environment influenced the genetic diversity of insular populations, 2 - to understand the intensity of genetic differentiation and gene flow of the insular population of E. fulgens in Alcatrazes, and 3 - to estimate changes in the mating system of the island population. For this, it is necessary to carry out the analysis and genetic comparison of the plants on the island and on the mainland, using PCR and microsatellite markers. It is important to emphasize that the sample group is 34 individuals from 2 different populations on the island and 40 individuals distributed in two continental populations. Through methods of descriptive genetics, gene flow analysis and assignment tests, we intend to investigate the changes that the insular environment can cause in a population.