Few creatures give us humans the creeps as much as tarantulas do, although these huge spiders don’t pose a threat for our species except for a painful bite. While for most people, tarantulas are scary because of their imposing and hairy looks, these spiders have even become popular pets for arachnid enthusiasts.
ScienceAlert.com writes about how tarantulas are extremely prevalent throughout the globe and about the scientists’ explanation for it.
Tarantulas are present across the tropical regions of all continents
The statement of a research team led by Saoirse Foley, a bioinformatician from Carnegie Mellon University, writes:
They are quite widespread and are found throughout the subtropical regions of every continent.
Another statement of the research says:
[Their] behaviours do not portend that tarantulas would be successful dispersers, yet they have spread across the globe and have colonized strikingly different ecological niches.
The scientists had been analyzing messenger RNA in tarantula transcriptome databases. They also modelled how the tarantura’s family tree could have unfolded over a period of 120 million years of evolution. That ancestry could have been the key to the tarantula’s prevalence. It is believed that early tarantula ancestors spread throughout the world via continental drift when huge landmasses roamed and collided after the disruption of the supercontinent Gondwana. About 550 million years ago in the Neoproterozoic marked the beginning of Gondwana, while the break up occurred during the Jurassic, meaning about 180 million years ago.
The researchers also wrote:
Interestingly, despite our analyses suggesting a Gondwanan origin for Theraphosidae, this pattern suggests that tarantulas were not always present in Oceania, and instead is consistent with Selenocosmiinae having diversified across Asia, eventually crossing the Wallace line sometime after the India/Asia collision (possibly as early as 47 Ma, Fig. S3), while the terrestrial Thrigmopoeinae remained in India.
The new findings were reported in PeerJ.