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Animals Evolve Larger Limbs to Adapt to Rising Temperatures

By: Alice Lipscombe-Southwell
Originally Published in  
Science Focus
A tiny mouse standing on a stick with plants in the background
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Vocabulary

Evolution (noun): The process by which different kinds of living organisms develop and diversify from earlier forms.

Dissipate (verb): To scatter or spread out, such as heat or energy.

Appendage (noun): An external body part that protrudes from an organism's body.

Specimen (noun): An individual animal, plant, or mineral used as an example of its species or type for scientific study.

Climate change is influencing animal evolution in noticeable ways.

Bigger body parts, better cooling

As global temperatures rise, warm-blooded animals are adapting by altering their physical features. According to a study published in Trends in Ecology & Evolution, species like birds and mammals are developing larger ears, beaks, and limbs to better dissipate body heat.

Parrots are growing bigger beaks

This phenomenon aligns with Allen's Rule, which states that animals in warmer climates tend to have larger appendages to release heat more efficiently. For instance, Australian parrots, such as the crimson rosella, have shown a 4% to 10% increase in beak size since 1871. Similarly, the dark-eyed junco, a North American songbird, exhibits changes in bill size correlating with temperature extremes.

How scientists know this is happening

These adaptations are subtle and may not be immediately noticeable, but they indicate a rapid evolutionary response to climate stressors. Researchers are utilizing 3D scans of museum specimens to track these morphological changes over the past century.

Will animals be able to keep up?

Scientists caution that while some species are adapting, others may not cope as effectively with the accelerating pace of climate change. Further studies, including genetic research, are necessary to understand which animals are most likely to survive in a warming world.

© Alice Lipscombe-Southwell / Our Media