Natural Resources, School of
Robert M. Zink
Date of this Version
Genetic techniques are being more frequently used to understand the biology and management of wildlife species. The wild turkey is one species of genetic interest because the correct identification of individuals to the subspecies level is difficult using traditional methods. Currently phenotypic differences in plumage, especially the upper tail coverts, are used to assign individuals to subspecies. To hunters wanting to complete a “grand slam,” identification of birds’ subspecies is important. This study focuses on the five extant subspecies: Eastern (M. g. silvestris), Osceola (M. g. osceola), Rio Grande (M. g. intermedia), Merriam’s (M. g. merriami), and Gould’s (M. g. mexicana). I aimed to determine if molecular genetic data provide support for currently recognized subspecies. I also attempted to determine if quantitative measurements of coloration of the upper tail coverts is geographically discrete and consistent with historical subspecies boundaries. I used primer sets for 11 single nucleotide polymorphisms thought to be diagnostic at the subspecies level and sequenced DNA of tissue samples from 81 birds to determine whether they were pure examples of a subspecies or hybrids. To measure plumage coloration, I used a spectrophotometer to obtain quantitative measurements of upper tail coverts from individuals obtained in 21 states and all subspecies. Genetic analyses suggested that most wild turkeys in Nebraska represent a mixture of many subspecies. Morphological analyses indicated that there are not five distinct spectral ranges that correspond with accepted subspecies, but most likely two that roughly divide turkeys from east to west. These analyses plus comparison of mitochondrial genomes suggests that the genetic landscape of wild turkey is basically divided into eastern and western groups. To explore the use of molecular phylogenetics in wildlife genetics I also did a study on the evolution of Transmissible Spongiform Encephalopathies across 102 species of mammals. Phylogenetic hypotheses for the prion protein gene, thought to be responsible for transmissible spongiform encephalopathies, and a species tree inferred from 20 unlinked nuclear genes, were compared, finding highly congruent topologies. Mapping the presence/absence of TSEs on the species tree, TSEs occur non-randomly and have arisen independently and recently in different mammalian groups. This suggests that the evolution of TSEs develops in groups of species irrespective of PRNP genotype.
Advisor: Robert M. Zink
Genetics Commons, Genomics Commons, Natural Resources and Conservation Commons, Natural Resources Management and Policy Commons
A THESIS Presented to the Faculty of The Graduate College at the University of Nebraska In Partial Fulfillment of Requirements For the Degree of Master of Science, Major: Natural Resource Sciences, Under the Supervision of Professor Robert M. Zink. Lincoln, Nebraska: April, 2020
Copyright 2020 Brittaney L. Buchanan