How living systems adjust to heat, one gene at a time
06-16-2026
When temperatures rise, living organisms don’t just endure the change—they respond in real time.
A new study from Purdue University takes a closer look at how that response unfolds at the genetic level, offering insight into how freshwater ecosystems may shift as the climate warms.
Researchers focused on a small but essential freshwater species often found in lakes and ponds. These organisms play a key role in aquatic food webs, helping control algae and serving as a food source for larger species. Because of their ecological importance, understanding how they respond to temperature changes can reveal broader patterns about ecosystem health.
The team- including Professors Mark Chirstie and Catherine Searle, postdoc Nathan Backenstose and Ph.D candidate Allison Nalesnik, all of Purdue Biological Sciences- examined how gene activity and reproduction changed during a short period of elevated temperatures, designed to reflect a moderate heat wave. Rather than remaining static, the organisms showed a dynamic, time-dependent response—adjusting their biology in stages over the course of a week.
At the start of the temperature increase, the organisms activated genes linked to reproduction. This early response suggests a shift toward producing offspring quickly, a strategy that may help populations persist during sudden environmental stress. In simple terms, when conditions begin to change, the organisms appear to prioritize reproduction.
By the end of the week, that strategy had shifted. Gene activity moved away from reproduction and toward metabolism—the internal processes that help maintain energy and basic function. This later response reflects a transition from rapid adjustment to longer-term survival, as the organisms adapted to sustained higher temperatures.
“These changes show that the response to environmental stress isn’t one-size-fits-all,” the Christie noted. “It evolves over time, with different biological priorities emerging at different stages.”
The study also found that individuals exposed to higher temperatures produced more offspring overall compared to those in stable conditions. This increase in reproductive output, combined with the shifting genetic response, highlights the flexibility organisms can exhibit when faced with environmental change.
At the heart of the research is gene expression—the process by which information in DNA is turned into action. While DNA provides the blueprint, gene expression determines which instructions are carried out at any given time. The researchers describe this process like a musical score: the DNA contains the notes, but gene expression is the performance, changing based on the environment.
This ability to “tune” gene activity allows organisms to respond quickly without altering their underlying genetic code. It’s a key mechanism for short-term adaptation and can influence how populations fare in changing conditions.
The findings contribute to a growing body of work aimed at understanding how species respond to climate variability. As heat waves become more frequent and intense, even short-term temperature spikes can have lasting effects on ecosystems. By identifying how foundational species adjust at the molecular level, scientists can better predict how entire communities may shift.
In freshwater systems, those changes could ripple outward. Alterations in population size or behavior at the base of the food web can affect water quality, nutrient cycles, and the species that rely on these organisms for food.
Understanding those patterns is essential for anticipating how life will adapt in a warming world.
About the Department of Biological Sciences at Purdue University
The Department of Biological Sciences is the largest life sciences department at Purdue University. As part of Purdue One Health, we are dedicated to pioneering scientific discoveries and transformative education at the cutting edge of innovation. From molecules to cells, from tissues to organisms, from populations to ecosystems- we bring together multiple perspectives, integrating across biological scales to advance our understanding of life and tackle the world’s most pressing challenges. Learn more at bio.purdue.edu.
Written by: Alisha Willett, Senior Communications Specialist, amwillet@purdue.edu
Contributors: Mark Christie, christ99@purdue.edu