An international research project involving the University of Granada has unified more than 30,000 thermal performance measurements in some 2,700 species
An international team of researchers, including members from the University of Granada, has developed a mathematical model that predicts with unprecedented accuracy how temperature affects all levels of life, from enzymes to entire ecosystems. The study, which has just been published in the journal Proceedings of the National Academy of Sciences (PNAS), reveals that there is a universal curve that describes this behavior in virtually all living organisms, a finding that will revolutionize our understanding of the impact of global warming on nature.
The study involved Ignacio Peralta Maraver, a researcher in the Department of Ecology and the Modeling Nature (MNat) Unit of Excellence at the University of Granada, Jean-François Arnoldi, from the CNRS Theoretical and Experimental Ecology Station in Moulis (France), and Andrew L. Jackson and Nicholas Payne, from the Department of Zoology at Trinity College Dublin. The research shows that, from the molecular level to the ecosystem scale, all processes that vary with temperature can be unified under a single mathematical equation.
The universal pattern of nature
For Ignacio Peralta-Maraver, “this model could become a new standard in the ecology and physiology of global warming.” All living beings are affected by temperature, but the newly validated mathematical equation—the Universal Thermal Performance Curve (UTPC)—unifies tens of thousands of seemingly distinct curves that explain how species function at different temperatures. Most surprisingly, the UTPC seems to apply not only to all species, but also to any measure of their performance in the face of thermal variations: from lizards running on a treadmill to sharks swimming in the ocean to the rate of cell division in bacteria.
The most relevant aspect of the new UTPC is that it shows a common pattern: as organisms warm up, their performance slowly increases until it reaches an optimum (where it is at its maximum), but with further warming, performance declines rapidly. This rapid decline above the optimum temperature means that overheating can be dangerous, with the risk of physiological failure or even death. One of the clearest conclusions of the study is that species may be more limited than feared in their ability to adapt to global climate change, given that temperatures continue to rise in most regions.
Understanding how species adapt to change
The results of the study are consistent across an analysis of more than 30,000 different performance measures and a huge diversity of species: from bacteria to plants, and from lizards to insects. This means that the pattern holds across species from all major groups that have diverged widely over billions of years of evolution.
Despite this great biological diversity, the study shows that, in essence, all life forms remain remarkably constrained by this “rule” that dictates how temperature influences their ability to function. The most that evolution has achieved is to shift the curve up or down, but life has not found a way to deviate from this specific form of thermal performance.
The next step in the research will be to use this model as a reference to identify whether there are species or systems that, even in a subtle way, manage to escape this pattern. If they are found, we will have to ask ourselves why and how they do so, especially given the projections of an increasingly warmer climate in the coming decades.