Evolution of skunks (Carnivora: mephitidae) across the Mexican transition zone: Understanding the influence of environmental variation on morphological and phylogeographic patterns

Abstract

For this dissertation I used quantitative assessments of morphological and genetic characters to examine how variation in these traits could be used to shed light on the evolutionary history of one the world’s most ubiquitous mammals: skunks. Currently representing 12 species, the skunk family Mephitidae includes a diverse assemblage of small- to mid-sized carnivores distributed throughout North and South America as well as islands in Southeast Asia. However, a majority of skunk diversity (8 spp) can be found within what is now identified as the Mexican Transition Zone (MTZ), a biotically diverse region spanning the Neotropical and Nearctic biogeographical realms from southwestern USA through Mexico and into parts of Central America. Through application of a set of integrated techniques, I set out to address and compare morphological, genetic, and ecological variation in three species of skunks, the American hog-nosed skunk (Conepatus leuconotus), the hooded skunk (Mephitis macroura), and the western spotted skunk (Spilogale gracilis). Specifically, I addressed the following questions: 1) How does color-pattern variation in the American hog-nosed skunk differ across its range and in relation to localized environmental conditions? 2) How did Pleistocene climate change across the MTZ influence the genetic and demographic history of C. leuconotus? and 3) How do ecological characteristics of co-distributed skunk species across the MTZ affect their response to global climate change during the Quaternary? Results from this work have helped to increase our understanding of the evolution of color patterns, response to changing climates, and roles of ecological traits in shaping genetic structure for this diverse and enigmatic group of small carnivores.

Description

Rights

Availability

Access is not restricted.

Keywords

Conepatus Leuconotus, Spilogale Gracilis, Mephitis Macroura, Ecological Niche Modeling, Phylogeography, Color Polymorphism, Aposematism

Citation