These Spiders Sailed Completely Around the World

A spider of the genus Amaurobioides. (Credit: Ceccarelli et. al/PLOS ONE) Millions of years ago, a species of small spiders took to the high seas and conquered the globe. Well, conquered may not quite be the right word, but spiders of the genus Amaurobioides did manage to completely circumnavigate the globe, spanning vast oceans and leapfrogging across continents, long before human explorers attempted the feat. Using a genetic analysis of the spiders evolutionary tree, researchers from Argentina, Africa, Australia and the U.S. determined that the species set out from South America during the Miocene Epoch, sailing first to Africa and then Australia before bringing their journey full circle in Chile. All told, the researchers estimate the trip took them around 8 million years.