Detecting concerted demographic responses to marine transgressions in plant species from the Alcatrazes Island, southeastern Brazil

• Grant number: 23/13495-0
• Support Opportunities: Scholarships abroad - Research Internship - Master's degree
• Start date: February 01, 2024
• End date: July 31, 2024
• Field of knowledge: Biological Sciences - Ecology
• Principal Investigator: Fábio Pinheiro
• Grantee: Raphael da Silva
• Supervisor: Marcelo Coelho Miguel Gehara
• Host Institution: Instituto de Biologia (IB). Universidade Estadual de Campinas (UNICAMP). Campinas , SP, Brazil
• Institution abroad: Rutgers The State University of New Jersey, Newark, United States
• Associated to the scholarship: 22/15747-3 - Genetic structure between insular and continental populations of species with different dispersal syndromes, BP.MS

Abstract

Several islands are found on the southeastern coast of Brazil, most of which were connected to the mainland during the last glacial period. Among such islands is the Alcatrazes Island, one of the most isolated coastal islands in southeastern Brazil. Various marine transgressions and regressions may have played a significant role in the origin and evolution of organisms in this region, including the evolution of endemic island species. Since a large portion of the island's flora is shared with the adjacent mainland, it is possible to investigate the demographic dynamics of populations in order to understand events of population expansion and contraction, as well as synchronicity in demographic changes. This study aims to: 1) assess the demographic dynamics of Eugenia sulcata Spring ex Mart. (Myrtaceae), Schinus terebinthifolia Raddi (Anacardiaceae), and Chiococca alba (L.) Hitchc. in a comparative approach; 2) quantify the connectivity between island and mainland populations; and 3) gain insights into how marine transgressions and regressions have influenced population sizes. Genomic data generated from RAD sequencing of populations from Alcatrazes Island, Montão de Trigo Island, and the adjascent mainland will be used for demographic analyses using the Hierarchical Approximate Bayesian Computation (hABC) method. The results of this study will clarify aspects of the origin and evolution of the flora of Alcatrazes Island, providing genomic data on these species that will be essential for understanding the evolution of organisms in island environments.