American scientists have figured out how tarantulas spread throughout the Earth
Tarantulas are found on all continents of the Earth, except Antarctica. For a long time, scientists could not understand how these spiders spread across the planet, because by nature they are not prone to long migrations. Females rarely leave their burrows, spiders stay close to the hatching site, and adult males only travel in search of a pair, according to PeerJ.
The authors of a new study from Carnegie Mellon University found the answer to this question by reconstructing the family tree of tarantulas. In this they were helped by the analysis of the protein-coding part of the genome found in ribonucleic acid (RNA).
The genetic data was compared with the preserved fossils. The results of the study showed that the first tarantulas appeared in the days of the dinosaurs, about 120 million years ago, in the territory of modern America.
During this era, America was part of the supercontinent of Gondwana. The ancient ancestors of tarantulas, moving overland, settled in areas that later became Africa, Australia and India. Then Gondwana disintegrated, India separated from Madagascar and collided with Asia 55-35 million years ago – this is how the spiders got to this continent.
Even before arriving in Asia, tarantulas from India were divided into two groups: some lived in trees, and others in burrows. Studying them, scientists found traces of two waves of migration. Both lines eventually spread across Asia, but the arboreal group (Ornithoctoninae) did so 20 million years later than their burrowing cousins.
The study found that spiders were able to fill ecological niches and adapt to new habitats more efficiently than was once thought. Scientists concluded that although continental drift played a significant role in the dispersal of spiders, they themselves displayed outstanding survival abilities.
“The species have seized the opportunity to benefit from the new environmental conditions. Different families occupied different ecological niches and were able to survive without competing with each other, ”the authors noted.
Earlier it was reported that a new species of tarantulas was discovered in Australia. They are great at disguising themselves.
