Caribbean: Hurricanes affect the evolution of lizards

It was a coincidence that Colin Donihue came to investigate how a hurricane affects the development of lizard species. In fact, Donihue and his team have been doing research on the lizards of the Turks and Caicos Islands in the Caribbean for quite different reasons. However, after the scientists left, the islands were hit by hurricanes Irma and Maria.

Donihue then decided to return only a few weeks after the storms. Because his collected data offered him a rare opportunity: he could investigate if hurricanes had acted as a selection process. Lizards whose characteristics have survived? And what did the storm take away?

Since the lizards of the species Anolis scriptus differ significantly from the hurricanes of their species before the natural disaster, probably a natural selection has occurred, the researchers write in the journal "Nature".

For their study, they studied the length of limbs and feet of lizards. They discovered: After the hurricanes found on the islands suddenly more lizards with big feet and long front legs. Presumably, they had survived the storms.

In addition to natural selection, there may have been other reasons to have larger feet and longer legs. Researchers can not exclude that lizards have been blown from other parts of the island to the study site, which has longer legs and larger feet. However, they consider this improbable because the islands are small and the vegetation is homogeneous.

Lizards in the Storm

In addition, there are already studies showing that larger feet in lizards are badociated with better stapling capability. This is also an indication that after the storms were not accidentally more lizards with larger feet on the islands, but they had an advantage and rather survived.

How lizards behave in hurricanes, is still poorly understood. As a result, the researchers made another investigation in which they exposed and filmed nearly 50 island lizards in a strong wind. So, they could watch what the lizards would do in a hurricane.

Lizards held their front legs to a pole, the only support for the experimental setup offered. In any case, until the wind gets too strong – no animal could hang in the end. Thanks to the protective nets and padding, all the lizards were released without damage after the test.

Climate change is expected to increase natural disasters such as hurricanes in the coming decades. Therefore, it may become more important to know how such events influence evolution.