Surviving climate change
When the Earth's climate changes, many species become extinct. But certain characteristics actually make organisms more robust - at least if the change is not too severe.
The Earth's climate has changed again and again over the course of its history - irretrievably wiping out countless animal and plant species that had previously flourished. However, while we know from fossilised traces of past biodiversity that a rapidly changing climate decimates significant parts of biological diversity, it is much less clear who all disappears from the scene and why. A recent study, published in the journal "Science", now suggests that the extinction of species due to climate change is by no means determined by chance alone. As reported by a team led by Cooper M. Malanoski from the University of Oxford, certain characteristics make species more likely to become extinct than others when global temperatures fluctuate.
The team analysed nine classes of invertebrates that have lived in the sea over the past 485 million years, including sea urchins, trilobites and snails. In addition to body size and geographical distribution, the researchers analysed three factors related to temperature. Firstly, what temperature an organism prefers, secondly, how large a temperature deviation the organism can still tolerate, and finally, how much the temperature actually changed during the study period. In addition, the experts used a climate model to model three global warming events 335 million, 69 million and 5 million years ago in order to obtain precise information about the conditions in the respective habitats.
It is already known that organisms with a smaller distribution area generally die out more easily - which was also shown in the study. According to the findings of the working group, the same also applies to temperature: the wider the temperature range in which a marine animal normally lives, the better it copes with climate change. In addition, animals in cooler waters died out less frequently than those in warm climate zones. The body size of marine animals also appears to play a role in their sensitivity to temperature fluctuations. In addition, the magnitude of the fluctuations makes a difference to species extinction: The more drastically the climate changed in a habitat, the more animals disappeared.
This is not surprising at first, but there is a small peculiarity that the working group emphasises in its conclusion: the greater the rise in temperature, the smaller the influence of the other factors. In a strong climate change, the "protective effect" of actually favourable characteristics diminishes, and the difference between robust and vulnerable species becomes smaller. In major climate crises, organisms that are widespread and can tolerate very different temperatures also die out. If the climate changes too much, the study concludes, no species will be safe.
Spectrum of Science
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