Are phylogenetic comparative models of trait evolution adequate when budding speciation is frequent?

• Grant number: 19/27212-4
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• Start date: October 01, 2020
• End date: December 31, 2021
• Field of knowledge: Biological Sciences - Ecology - Theoretical Ecology
• Principal Investigator: Tiago Bosisio Quental
• Grantee: Daniel Caetano da Silva
• Host Institution: Instituto de Biociências (IB). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

Knowing the phylogenetic relationship among lineages allows us to study patterns and processes of evolution and take into account historical factors that might be responsible for traits shared among closely related taxa. The acknowledgment of evolutionary relatedness has changed the way we ask biological questions in a fundamental way. Incorporating the history of populations and species is crucial to study macroevolution directly as well as to ask ecological and evolutionary questions involving multiple populations or species. Phylogenetic comparative methods (PCMs) are central to this approach and have been widely used to study macroevolution based both on phylogenies and the fossil record. However, with the widespread use of these approaches, comes the need to evaluate if such models are adequate to answer our questions and, more importantly, if they are able to return reliable estimates under realistic scenarios of evolution. Here we propose to investigate how the mode of speciation influences PCMs. More specifically, we question two assumptions of the majority of PCMs: a) speciation events generate two new identical lineages, with the dissolution of the ancestral, and b) ancestral states can be estimated as a simple weighted average of descendants. This is in contrast with the paleontological literature which very often recognizes that budding speciation happens frequently-meaning that ancestral lineages can outlive speciation (not dissolved at cladogenetic events) and ancestor-descendant pairs can be found at the same time period. We will use extensive simulations as well as an empirical dataset on Macroperforate Foraminifera, which has an extraordinary fossil record, to evaluate how budding speciation influences our estimates of trait evolution using phylogenetic comparative models. We will also introduce a novel model that allows rates of trait evolution to vary in function of lineage age.