Biology ETDs
Publication Date
Summer 2026
Abstract
Variation in genotype, phenotype, and environmental characteristics are considered defining taxonomic features in natural ppopulations, but genetic variation among individuals with the same phenotypes can lead to taxonomic uncertainty. The plains spadefoot (Spea bombifrons) and the New Mexico spadefoot (Spea multiplicata) overlap geographically throughout the southwestern United States and have been known to hybridize where they come into contact, further contributing to taxonomic uncertainty. Using double-digest RADseq genetic data, traditional morphological measurements, and environmental niche modeling, we aimed to 1) describe genetic variation across New Mexico, 2) describe morphological variation and 3) quantify niche space occupied by both species in New Mexico. Here, we found deep divergence between the two species as well as unique lineages within each, but did not find strong support for morphological differentiation between the species, and niche overlap of 0.225. Genetic divergence, limited morphological differentiation, and partial niche overlap points to a dynamic evolutionary system with important implications for hybridization, range change, cryptic morphology and herpetological conservation work in the Desert Southwest.
Language
English
Keywords
evolution, population genomics, frogs, variation, Desert Southwest, biogeography
Document Type
Thesis
Degree Name
Biology
Level of Degree
Masters
Department Name
UNM Biology Department
First Committee Member (Chair)
Lisa Barrow
Second Committee Member
Michael Anderson
Third Committee Member
Thomas Turner
Recommended Citation
Mason, Noelle. "CHARACTERIZING GENOMIC, MORPHOLOGICAL, AND ENVIRONMENTAL VARIATION IN DESERT SPADEFOOTS." (2026). https://digitalrepository.unm.edu/biol_etds/666