New Research From Murdoch University Reveals Cold Blooded Species Lack Physiological Ability to Adapt to Climate Fluctuations

Murdoch University study finds ectotherms lack the physiological ability to adjust to daily temperature changes, increasing climate change risks.

By: AXL Media

Published: Mar 20, 2026, 9:21 AM EDT

Source: Information for this report was sourced from Murdoch University

Challenging Assumptions About Ectothermic Adaptation

A new study led by Dr. Daniel Gomez Isaza at Murdoch University’s Harry Butler Institute has overturned long-standing biological assumptions regarding how cold-blooded animals manage environmental stress. For decades, the scientific community operated under the framework that ectotherms—animals such as fish, reptiles, and invertebrates that rely on external heat—could physiologically fine-tune their internal systems to become less sensitive to daily temperature changes. However, after analyzing data across 26 separate studies, researchers found no consistent evidence that these species adjust their metabolism or heart function to stabilize themselves against fluctuating conditions.

The Internal Vulnerability of Cold Blooded Species

Because the internal temperature of an ectotherm closely mirrors its immediate surroundings, daily variations in heat are highly consequential for its survival. The research team examined various physiological markers, including locomotor performance, cardiovascular health, and enzyme activity, expecting to see signs of acclimation. Instead, the results showed that these animals remain largely unresponsive to short-term environmental shifts. According to Dr. Gomez Isaza, this suggests that ectotherms possess a surprisingly limited capacity for regulating their internal physiology to handle the predictable temperature swings that characterize natural habitats.

Climate Change and the Threat of Increased Variability

The inability to physiologically adapt poses a severe threat as global climate patterns become increasingly erratic. While ectotherms have evolved to live within certain thermal ranges, climate change is driving more extreme and unpredictable daily temperature spikes. Dr. Essie Rodgers, a co-author of the study, noted that this physiological rigidity exposes a critical vulnerability. As these fluctuations become more common, the lack of internal flexibility means that animals may be pushed toward their thermal limits more frequently, potentially leading to widespread population declines in sensitive ecosystems.