EEB graduate student Andréa Thomaz is the 2016 recipient of the Donald W. Tinkle Scholarship from the U-M Museum of Zoology. UMMZ's most prestigious student award is a special recognition of research excellence and is intended to assist students in completing their doctoral research.

Thomaz tackles her research interests of population genetics, speciation, phylogenetics and evolutionary biology in the river basins along the Atlantic coast of southern Brazil. “Multiple processes that result in similar patterns confound the underlying mechanisms promoting genetic variation in riverine fishes,” said Thomaz. For example, geographic barriers (such as a waterfall), constraints imposed by physical properties of a river (if the river is branched or linear) and species’ ecological requirements affect the dispersal of organisms and, consequently, the genetic differentiation among populations. “My Ph.D. dissertation is a step towards addressing this issue by disentangling the effect of these three processes on patterns of genetic structure of freshwater fishes in a system of drainages along the Atlantic coast of Brazil.”

Thomaz is working with tetras (characins), primarily four species endemic to her study region that occupy different portions of a river: generalist Mimagoniates microlepis, headwater Bryconamericus microcephalus, forest specialist Hollandichthys multifasciatus and lowland Hyphessobrycon boulengeri.

“By using new sequencing technologies and hypotheses testing statistical approaches, I’m able to understand the processes responsible for generating the high species diversity and strong genetic structure observed among populations of fishes in the region. This approach also provides insights into which river portions are critical to conservation efforts because of their impact in population persistence and movement patterns of organisms living in these environments.”

There are over 500 species of freshwater fishes in Thomaz’s study region. The long but very narrow area is relatively small for its incredible diversity. Over 100 species of tetras live in this area, many of which (including some that she works on) are known to be species complex, meaning there is likely an undescribed diversity waiting to be discovered. This is especially problematic in her study region, which is the most urbanized area in Brazil. This puts the fish at risk of extinction before many of these species are formally identified.

Professor Lacey Knowles, Thomaz’s advisor, notes that not only is she a talented communicator who has received awards for her presentations at national meetings and a National Science Foundation Dissertation Improvement grant, but she has already successfully published several aspects of her dissertation work. In addition, Thomaz has been a key contributor to the University of Michigan’s Museum of Zoology, through her work for the Fish Division and the thousands of specimens she has collected

“During Dea’s time in the UMMZ, she has conducted research and published on a broad range of topics in systematics and evolutionary biology,” Knowles said. “It is only because of this tremendous knowledge of the fishes that she studies that she is able to address questions in which the insight extends far beyond the taxonomic group.”

Knowles also notes that Thomaz generously shares her knowledge with others, including as serving as a mentor to new students and postdocs in the lab. “She has a pronounced enthusiasm for science that is absolutely contagious, raising the level of interaction and fostering a supportive environment in the lab for other students to express themselves.”

Thomaz is a great representative for the Museum of Zoology as a graduate student research assistant in the Fish Division, organizing social events and seminars, serving on departmental committees and actively participating in outreach programs such as the annual museums’ ID Day and leading tours of the Fish Division.

“With her active collaborations in Brazil, the impact of her research extends to her native country Brazil, where she plays an active role in facilitating the development of resources (in terms of specimens added to museum collections) and contributing to conceptual advances by bringing the power of next-generation sequencing and powerful statistical approaches to studies of biodiversity,” Knowles added.

The scholarship was endowed by the family and friends of Dr. Tinkle, who joined U-M in 1965 as professor and curator of reptiles and amphibians. Tinkle became director of the Museum of Zoology in 1975 and served until his death in 1980. He received many honors including being elected a fellow of the American Association for the Advancement of Science and the Herpetologists League, and was awarded a John Simon Guggenheim Fellowship and the Ecologist Award from the Ecological Society of America.

He was a systematist, an evolutionary biologist, an evolutionary ecologist and an exceptional teacher whose most important legacy is the group of students he inspired. In the field, especially, he was known for his enthusiasm, endurance and sense of humor. The $5,000 scholarship awarded to an outstanding student in the Museum of Zoology each year in his name is intended to help students complete their doctoral research.