Presentation Title

Investigating the Biogeographic History and Diversification of Caribbean Spiders in the Genus Eriophora through Molecular Phylogenetics

Abstract

Arthropoda is the most species-rich group on earth, and yet one of the most understudied. The great biodiversity of the Caribbean islands inspired the Caribbean Island Biogeography (CarBio) project. The goal of this project is to gain a better understanding of speciation processes, colonization history and dispersal patterns in the Caribbean. Our study focuses specifically on Eriophora, a genus of orb-weaving spiders. Eriophora is native throughout the Caribbean islands, South America, and the southern belt of North America. Through the CarBio project we obtained specimens from throughout the region. We sequenced two markers, CO1 and ITS2, to generate a phylogenetic tree, and used it to explore the origin, dispersal mechanisms, and speciation pattern of Caribbean Eriophora. In particular, we tested the GAARlandia hypothesis stating that the Major Antilles islands were interconnected and together linked to South America via a landbridge that existed 30-33 million years ago. We found evidence that the Eriophora Caribbean phylogeny is very diverse and not monophyletic. These results suggest multiple over-water colonization events that do not support the GAARlandia hypothesis but support ballooning as Eriphoras dominant mode of dispersal.

Primary Faculty Mentor Name

Ingi Agnarsson

Status

Undergraduate

Student College

College of Arts and Sciences

Program/Major

Biological Science

Primary Research Category

Biological Sciences

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Investigating the Biogeographic History and Diversification of Caribbean Spiders in the Genus Eriophora through Molecular Phylogenetics

Arthropoda is the most species-rich group on earth, and yet one of the most understudied. The great biodiversity of the Caribbean islands inspired the Caribbean Island Biogeography (CarBio) project. The goal of this project is to gain a better understanding of speciation processes, colonization history and dispersal patterns in the Caribbean. Our study focuses specifically on Eriophora, a genus of orb-weaving spiders. Eriophora is native throughout the Caribbean islands, South America, and the southern belt of North America. Through the CarBio project we obtained specimens from throughout the region. We sequenced two markers, CO1 and ITS2, to generate a phylogenetic tree, and used it to explore the origin, dispersal mechanisms, and speciation pattern of Caribbean Eriophora. In particular, we tested the GAARlandia hypothesis stating that the Major Antilles islands were interconnected and together linked to South America via a landbridge that existed 30-33 million years ago. We found evidence that the Eriophora Caribbean phylogeny is very diverse and not monophyletic. These results suggest multiple over-water colonization events that do not support the GAARlandia hypothesis but support ballooning as Eriphoras dominant mode of dispersal.