Unraveling the Paradox of the 'Great Speciators': Evolutionary Dynamics of a Geographic Radiation of Island Kingfishers (Todiramphus)

Author

Jenna Merle McCulloughFollow

Publication Date

5-10-2024

Abstract

The paradox of the ‘Great Speciators’ describes a biogeographic pattern in which geographically widespread lineages have strong overwater dispersal capabilities, yet exhibit genetic and phenotypic divergence between islands, suggesting limited dispersal and cessation of gene flow. In my dissertation, I leveraged whole genomes and two comprehensive trait datasets of dispersal ability and plumage coloration of all described diversity within Todiramphus kingfishers, a rapid radiation of largely island endemic ‘Great Speciators.’ Chapter 1 reveals that whole genome datasets do not outright solve the evolutionary relationships of this clade and that widespread incomplete lineage sorting (ILS) and gene flow are sources of topological conflict. Chapter 2 shows that direct measures of dispersal ability indicate that island syndrome contributes to evolutionary trends towards flightlessness in flighted, island endemic birds. Chapter 3 establishes a connection between rapidly evolving plumage color and diversification rates and highlights genetic drift as a driver of plumage color evolution.

Project Sponsors

The University of New Mexico, UNM Center for Advanced Research Computing (supported in part by the National Science Foundation [NSF]), NSF (DEB 2112467 to Corinne E. Myers, Shannon J. Hackett, and Michael J. Andersen), the American Museum of Natural History Frank Chapman Research Grant, UNM Biology Department Alvin R. and Caroline G. Grove Research and Richard B. Forbes Conservation awards, British Ornithologists’ Union Small Ornithological Research Grant, and the American Ornithological Society Werner and Hildegard Hesse Research award

Language

English

Keywords

Alcedinidae, Whole Genome Resequencing, phylogenetics, dispersal, island syndrome, color evolution

Document Type

Dissertation

Degree Name

Biology

Level of Degree

Doctoral

Department Name

UNM Biology Department

First Committee Member (Chair)

Michael J. Andersen

Second Committee Member

Lisa N. Barrow

Third Committee Member

Joseph A. Cook

Fourth Committee Member

Corinne E. Myers

Recommended Citation

McCullough, Jenna Merle. "Unraveling the Paradox of the 'Great Speciators': Evolutionary Dynamics of a Geographic Radiation of Island Kingfishers (Todiramphus)." (2024). https://digitalrepository.unm.edu/biol_etds/591