Researchers at Trinity College Dublin have identified a universal thermal performance curve that governs how organisms across the tree of life respond to temperature changes. This pattern shows performance improving gradually up to an optimal point before declining sharply. The finding, based on analysis of over 2,500 curves from diverse species, suggests evolutionary constraints on adapting to warming climates.
A team from Trinity College Dublin reports the discovery of a universal thermal performance curve (UTPC) that applies to organisms from bacteria to insects and beyond. Published in the Proceedings of the National Academy of Sciences, the study analyzed more than 2,500 thermal performance curves spanning thousands of species and various biological activities, such as lizard running speeds, shark swimming, and bacterial cell division rates.
The UTPC describes a consistent pattern: as temperatures increase, biological performance rises gradually until reaching an optimal temperature, after which it falls rapidly. This holds across major branches of life evolved over billions of years, with optimal temperatures varying widely—from 5°C to 100°C—depending on the species and performance measure.
Andrew Jackson, a professor of zoology at Trinity and co-author, highlighted the uniformity: "Across thousands of species and almost all groups of life including bacteria, plants, reptiles, fish and insects, the shape of the curve that describes how performance changes with temperature is very similar." He added that all variations are essentially the same curve, shifted and stretched across temperatures, and that optimal temperatures link directly to critical maximums where death occurs.
Senior author Nicholas Payne emphasized the dataset's breadth: "These results have sprung forward from an in-depth analysis of over 2,500 different thermal performance curves, which comprise a tremendous variety of different performance measures for a similarly tremendous variety of different species—from bacteria to plants, and from lizards to insects."
The researchers note that once temperatures exceed the optimum, the viable range for survival narrows. They plan to use the UTPC as a benchmark to explore any exceptions, particularly amid ongoing climate warming.
