The largest changes in appendix size in the more than 30 animals examined in the review were found among some Australian parrot species, which saw their beak size increase by between 4% and 10%. average since 1871.
“It means animals are evolving, but it doesn’t necessarily mean they are coping with climate change. We can see that some species have increased the size of the appendix so far, but we don’t know if they will be able to keep up with the worsening climate crisis,” he said. Ryding by email.
“We also don’t know if these shape changes help survival (and therefore are beneficial) or not. This phenomenon of shape change should not be considered positive, but it is alarming that climate change is driving the animals will evolve like this, in such a short time. ”
He said the changes were subtle and unlikely to be noticed immediately, but that they could be “functionally important.”
While global warming was a “compelling argument” as a driving force behind these shape changes, the study said it was difficult to “establish causation with confidence” given the multifaceted effects that climate change has on the environment.
Smaller bodies, larger appendages
Within an animal species, individuals in warmer climates have larger appendages, such as wings and beaks, a pattern known as the Allen rule, with a larger surface area that allows animals to control their temperature more easily. point out the study.
At the same time, body sizes tend to shrink, as smaller bodies retain less heat.
“Both studies analyze how animals respond to climate change by altering their surface-to-volume ratio,” Ryding explained.
Although most research on morphological changes over time has focused on birds, the paper notes that shrews and bats have increased the relative size of the ears, tails, legs, and wings.
He said more research was needed on different species and different ecosystems to determine the extent of the phenomenon and that they could help predict which species might change shape in the future.
“Previous studies have shown cases where a change of form is taking place, but these have focused on individual species or groups. Our review article combines all of these to show the degree of diffusion of this phenomenon,” he said. dir Ryding.