Tracking the nature of evolutionary change

Seth Rudman magazine cover

Seth Rudman's study of rapid evolution in fruit flies has implications for conservation and human health.

Seth Rudman was set to start work as an assistant professor of biological sciences at WSU Vancouver for the 2020/21 academic year. But he was living in Ontario while completing a Canadian government fellowship at the time, and the border between the United States and Canada was closed because of COVID-19. So he was temporarily locked out of his job.

Fortunately for everyone, Rudman had a temporary adjunct title to hold his place and give him the academic credentials he needed to apply for grants before his formal appointment took effect on Aug. 16, 2021. He applied for a National Institutes of Health grant known as MIRA, for Maximizing Investigators’ Research Award, and in February 2022 he received it—$1.89 million over five years. He began teaching at WSU Vancouver that spring.

These rare and prestigious awards go to investigators early in their careers who show great promise. Unlike most grants, MIRAs are flexible, allowing the investigator to follow their nose and pursue different lines of research, as long as they are related to the overall purpose. Rudman, whose research goal is to gain a greater understanding of rapid evolution—the pace and predictability at which species evolve—primarily studies fruit flies (Drosophila melanogaster). But, as he wrote
in his MIRA application, the results have broad implications for human health, including our understanding of diseases such as cancer and COVID-19, as well as “understanding how global change alters populations and ecosystems that are central to human well-being.”

“The goal is to increase the efficiency of funding by providing investigators with more stability and flexibility,” Rudman said. “Those are exciting for me.” In addition, researchers must be working on a topic of interest to the National Institute of Health, whose purview is human health.

Seth Rudmans lab

An unusual labratory

Rudman arrived at WSU Vancouver in August 2021 as an assistant professor in the School
of Biological Sciences. He immediately began building his indoor-outdoor laboratory. “That
was a really fantastic thing WSU allowed me to do,” he said. “They gave me space to build an outdoor site to conduct replicable experiments in a natural setting. With a lot of help from my post- doc [René Shahmohamadloo], we built this and are able to use it to track evolutionary change over time.”

Rudman’s field lab is composed of fruit trees and fruit flies housed inside tent-like structures yet exposed to the elements. This setting allows selection pressures such as wind, rain and heat to act on the fruit fly populations. And the outdoor lab is large enough to expose different populations to different variables. The relatively harsh outdoor setting contrasts with the balmy atmosphere of Rudman’s indoor fruit fly room. “The conditions at the field site are more like natural conditions,” Rudman said, “and the purpose of that is to try to understand how variation in the genome influences evolutionary outcomes in more realistic settings. And that can help us predict things like how evolution is actually going to occur in pandemic settings or in a disease vector setting.”

At one time, the idea of evolution evoked thoughts of fossils and the slow pace of geologic change. “But evolution, at its heart, is heritable change,” Rudman said, “and that can happen fairly quickly from one generation to the next.”

Last fall, Rudman taught introduction to genetics. “Many instructors would say that genetics is one of the topics in biology that most strongly influences our daily lives,” Rudman said. “You don’t have to look far to see it. A COVID test is a genetic test. When we go to the grocery store, nearly all of the food available is shaped by artificial selection or direct genetic modification. When you go to the doctor, the ways we treat disease are strongly influenced by genetics, whether it’s the evolution of bacteria in response to antibiotics or more recent advances in personalized medicine. You have to turn a blind eye not to see genetics all around you.”

The importance of understanding how things evolve

Rudman grew up in Michigan, earned his undergraduate degree from the University of Rochester in New York and his Ph.D. from the University of British Columbia. He completed a postdoctoral fellowship at the University of Pennsylvania and a second fellowship with the Canadian government based at the University of Guelph. He was attracted to WSU Vancouver because of its Pacific Northwest location, its accessibility to outdoor activities, and the expertise of the faculty in evolutionary biology and ecology.

As a graduate student, he studied evolution by tracking change in stickleback fish. Fruit flies seemed better suited to his research, though— “not only because of their rapid reproduction but because of how much we know about them. They have been studied for well over 100 years,” he said. Because of this, their genomes are easy to sequence and analyze. Moreover, fruit flies can evolve rapidly, often within a single season.

"Understanding the process of evolutionary change can help us understand the evolution of things that have negative effectos on us weather pathogens or pests."

In a recent paper in the journal Science, he and his co-authors uncovered a phenomenon called “adaptive tracking,” a process through which a population responds to environmental changes through genetic changes. “That opens lots of questions about the extent to which rapid evolution is controlled by the identity of the genetic adaptation, and lots of questions about when and how rapid evolution can allow populations to exist in a rapidly degrading environment, such as rapid climate change,” Rudman said. “And those are the broad sorts of questions the MIRA grant funds: What factors promote and constrain the pace of evolutionary change, and how does evolutionary change promote the continuance or extinction of populations in a rapidly changing environment?”

Consider, for example, environmental conservation. “We are trying to understand whether biodiversity will persist in the face of climate change and habitat destruction,” Rudman said. “Are there things that can help us maintain the biodiversity we rely on?”

As for human beings, he said, “we see rapid evolution having effects on human health—COVID pathogens are an example. Understanding the process of evolutionary change can help us understand the evolution of things that have negative effects on us, whether pathogens or pests.”