Texas Tech University

Robert D. Bradley's Laboratory

Joanna Bateman
Teaching Assistant

Ph.D. student, Biology, Texas Tech Universityjoanna bateman
M.S. Biology, Brigham Young University
B.S. Biology, Brigham Young University


I have been researching and constructing the phylogenetic trees of the Heteromys pictus-spectabilis species complex (Painted spiny pocket mice and Jaliscan spiny pocket mice) since 2016 working on my Master's thesis under Dr. Duke Rogers. I began working in Dr. Bradley's lab in 2018, with the main goals of my PhD dissertation research being to determine the actual number of cryptic species present within the complex, to estimate their geographic distributions, and to predict the divergence history of these populations. This builds upon past evidence I have found that this species complex is actually composed of multiple cryptic species, and thus is in need of taxonomic revision. These questions will be primarily addressed through genome (RADSeq) sequencing and geographic data (Cytb haplotype networks, geographic barriers, etc.), using specimens collected across the overall habitat range.

Macy A. Krishnamoorthy (Madden)Macy Krishnamoorthy
Teaching Assistant

Ph.D. candidate, Biology, Texas Tech University
B.S. Biology, Brigham Young University


My dissertation evaluates different relationships of African bats. In the dissertation, I assess aspects of fruit bat pollination of baobab trees in South Africa and Kenya and identify relationships among the community of bats in southern Africa. I am interested broadly in small mammals, though I'd love to work with other mammals and invertebrates. Topics that interest me include ecological concepts, conservation, and natural history.

Emma K. Roberts

emma roberts

Postdoctoral Researcher, Texas Tech University
Ph.D. Biology, Texas Tech University
B.S. Biology, Texas Tech University


My research focuses on the molecular evolution of gamete recognition, specifically the sperm protein called zonadhesin, and its unique contribution to mammalian speciation and evolution. My post-doc work currently includes three main components of zonadhesin evolution: 1) investigating the origin of the gene that encodes zonadhesin across vertebrates, 2) characterizing zonadhesin's role in speciation among mammals at different stages of divergence (older species, sibling species, and hybrids), and 3) characterizing differential evolutionary pressures of zonadhesin (e.g. domain duplication, selection) as a mechanism to alter gamete binding specificity and therefore maintain a reproductive isolation barrier to fertilization.

Heidi Stevens
Curatorial Assistant

M.A. student, Museum Sciences, Texas Tech Universityheidi stevens
B.S. Biology, Universidad Nacional de Asunción, Paraguay


My interest in Museum Sciences centers on the care and utilization of natural history collections. There is a tension between the urgent need to preserve natural history specimens for future generations, and the imperative need to access these same resources for current research. Preservation and utilization of these finite resources drives my interest into curatorial management of natural history collections. My research focuses on improving curatorial practices as they relate to conservation of natural history collections along with their genetic resource materials. Currently, I am working on determining post-mortem degradation rates in mammalian tissues for optimal long term storage in liquid nitrogen.

Sarah Vrla
Teaching Assistant

Ph.D. student, Biology, Texas Tech Universitysarah vrla
M.S. Biology, University of Central Oklahoma
B.S. Biology, Cameron University


As an undergraduate at Cameron University, I conducted research involving ultraviolet (UV) vision in the Ord's kangaroo rat Dipodomys ordii. I then went on to get my Master's degree at the University of Central Oklahoma under the direction of Dr. Michelle Haynie where I investigated the genetic structure and potential hybridization of Peromyscus species. As a Ph.D. student, I hope to combine my previous research experiences by conducting research focusing on molecular ecology, specifically by using genetics techniques to begin to address sensory ecology questions relating to UV vision and communication of mammals. 

Emily Wright
Teaching Assistantteaching assistant

M.S. Biology, Texas Tech University
B.S. Zoology, Texas Tech University


In the summer of 2016 I started working in Dr. Bradley's lab, pursuing a Master's thesis. Currently, I am examining mechanisms that allow hybridization between White-tailed Deer (Odocoileus virginianus) and Mule Deer (Odocoileus hemionus).  I am exploring the role that zonadhesin (ZAN) plays in post-mating isolation. My ultimate goal is to obtain a Doctorate in Veterinary Medicine, specializing in the reintroduction of exotic species into their native habitats.

Natural Science Research Laboratory