Scientists have discovered a new universal law of organism vital activity

An international team of researchers has made a discovery that could overturn our understanding of the relationship between living organisms and temperature. It turns out that absolutely all forms of life — from tiny bacteria to large animals — obey a single law when environmental temperature changes. The results of this large-scale work have been published in the journal Proceedings of the National Academy of Sciences (PNAS).

Temperature is one of the key factors determining the vital activity of all living things on the planet. To study its influence, scientists have long used so-called thermal performance curves — graphs reflecting how effectively an organism copes with various tasks: cell division, movement, growth, and other processes.

Specialists from Trinity College Dublin carried out a colossal analytical effort, examining more than 2,500 such curves from numerous independent studies. The result turned out to be striking: despite the enormous differences between species, all curves share the same shape. This fundamental principle has been named the universal thermal performance curve.

The essence of the pattern is as follows: as temperature rises, biological activity gradually increases, reaching a peak point — the optimum at which the organism operates at the maximum of its capabilities. But once the temperature crosses this threshold, performance plummets rapidly. Overheating threatens serious physiological disruptions and can lead to death.

Notably, the optimal temperatures themselves vary across different species over an extremely wide range — from approximately 5 °C to 100 °C. However, the shape of the curve remains unchanged. As the authors note, over millions of years evolution has only learned to "shift" this curve along the temperature scale but has never managed to alter its fundamental shape.

Another important finding: the optimal temperature and the critical lethal threshold turned out to be closely interlinked. As soon as the temperature exceeds the optimum, the corridor of conditions in which the organism is capable of surviving narrows rapidly.

Lead author of the study Nicholas Payne emphasized that the conclusions are based on an enormous dataset encompassing the most diverse forms of life — bacteria, plants, fish, reptiles, insects, and many others.

This discovery takes on particular significance in the context of global warming. If evolution is indeed constrained by the framework of the universal curve, then the ability of species to adapt to rapidly rising temperatures may prove to be significantly more limited than previously thought.

In the next phase, the researchers intend to use the identified model as a benchmark and deliberately search for exceptions — organisms capable of at least partially deviating from the universal pattern. It is precisely such findings that could become the key to understanding how life on Earth is able to adapt to a rapidly changing climate.