Extinction selectivity in sloths (Xenarthra, Folivora): testing the deep-time effect of biotic traits

• Grant number: 24/09687-3
• Support Opportunities: Scholarships abroad - Research Internship - Scientific Initiation
• Start date: November 04, 2024
• End date: March 03, 2025
• Field of knowledge: Biological Sciences - Zoology - Paleozoology
• Principal Investigator: Pedro Lorena Godoy
• Grantee: Fernanda Dias Paes Landim
• Supervisor: Sebastian Hoehna
• Host Institution: Instituto de Biociências (IB). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Institution abroad: Ludwig Maximilian University of Munich (LMU Munich), Germany
• Associated to the scholarship: 23/16474-3 - Quantitative investigation of extinctions patterns in sloths (Xenarthra, Folivora) during the Cenozoic, BP.IC

Abstract

Along with the recent extinction of a great part of group species, sloths (Folivora) are remarkable for the significant loss of diversity along their evolutionary history, with the extinct diversity far exceeding that of living species. This loss of diversity may result from extinction events over geological time, such as the extinction of large mammals (collectively known as megafauna) during the Pleistocene-Holocene transition. Several factors may be associated with these extinctions, including biotic factors such as body size, substrate use (habitat) and diet, as well as abiotic factors like climate variation and habitat alteration caused by the significant uplift of the Andes during the Miocene. In this sense, this research project aims to investigate the selectivity of traits linked to extinction risk in Folivora during their evolutionary history. Initial analyses have identified phylogenetically clustered extinctions during the Miocene and Pleistocene. Now, the main focus is on understanding how body size, habitat and diet influence these extinctions using quantitative phylogenetic methods. More specifically, this project will employ phylogenetic regressions through Phylogenetic Generalized Linear Mixed Models (PGLMM) to explore the relationship between these traits and the extinctions, incorporating phylogenetic information from two distinct phylogenetic hypotheses. Ancestral state reconstructions and extracted literature data will be used for that. The BEPE internship at the Höhna Laboratory, renowned for its expertise in phylogenetic comparative methods, will be crucial to this study as it will provide advanced training in the software RevBayes, which will be used for the analysis. The expected results will be crucial to integrate with that of extinction patterns and enable a more comprehensive understanding of the evolutionary history of the group.