SNR Fall Seminar Series concludes with Thomas lecture

Steven Thomas
Steven Thomas

Steven Thomas, river and stream ecologist with SNR, will present the final lecture in the Fall Seminar Series at 3:30 p.m. Wednesday, Nov. 29, in Hardin Hall Auditorium. He will present "The Consequences of Local Adaptation in Stream Ecosystems: Ecological Roles and Species Distributions."

Most ecological research either explicitly or implicitly assumes that species traits are static over time based on the widely held belief that ecological and evolutionary processes operate over sufficiently different temporal scales. However, local adaptation can often be rapid following species invasions into new environments suggesting that ecological and evolutionary processes can interact with implications for the role organisms play in an ecosystem. We have been examining this topic using Trinidadian guppies (Poecilia reticulata) in their native ecosystems. The first portion of this presentation will summarize the results of our effort to quantify the ecological consequences of phenotypic variation using different experimental approaches. The second portion of this presentation examines how climate variability effects species distributions by comparing the altitudinal ranges of aquatic insects in Ecuador and Colorado. Results from this work indicate that aquatic insects in the tropics have reduced thermal tolerance, narrower altitudinal ranges and greater species turnover with altitude than their temperate counterparts. These results largely support Janzen’s prediction that ‘Mountain passes are higher in the tropics” because adaptation to local thermal conditions make tropical passes more effective barriers to dispersal than their temperate counterparts.

Steven Thomas is an associate professor in the School of Natural Resources at the University of Nebraska-Lincoln. Dr. Thomas was born in upstate New York and still has a home in the 1000 Islands. He holds degrees from the University of New Hampshire, University of Wyoming, and Idaho State University and completed postdoctoral fellowships at Virginia Tech and Cornell University before coming to Nebraska in 2006. In 2016, Dr. Thomas served as the Vice President for the Society for Freshwater Science. He currently serves as the chair of the Water Science Curriculum Committee and leader of the Environmental Science Mission Area.

Natural Resources