. | . |
Coastal spider ancestors may have dispersed eastward across Southern Hemisphere oceans by Staff Writers Washington DC (SPX) Oct 17, 2016
Coastal spiders may have undergone transoceanic dispersal eastward from South America to South Africa, Australia and New Zealand as the Amaurobioides genus evolved, according to a study published Oct. 12, 2016 in the open-access journal PLOS ONE by F. Sara Ceccarelli from Museo Argentino de Ciencias Naturales, and colleagues. Amaurobioides is a genus of coastal spiders found on three Southern Hemisphere continents: Australasia, Africa and South America. It was previously unclear whether an ancestral population existed on the ancient supercontinent Gondwana and was geographically separated when Gondwana broke up into modern day continents, or whether Amaurobioides arose on a single continent and later underwent long-distance, transoceanic dispersal to reach others. To address this question, Ceccarelli and colleagues considered mitochondrial and nuclear gene fragments, using DNA from 45 Amaurobioides specimens and 60 specimens from related taxa, as well as sequences from previous studies, to construct an Amaurobioides evolutionary tree. The researchers suggest that an ancestor of Amaurobioides may have dispersed eastward during the Miocene era from South America to South Africa, likely aided by the establishment of the Antarctic Circumpolar Current. The Amaurobioides genus originated in South Africa and dispersed further eastward to Australia and New Zealand in the early and mid-Pliocene. Finally, Amaurobioides species recolonized South America at the end of the Pliocene, completing the eastward circle of long-distance dispersal around the Southern Hemisphere. The coastal habitats of Amaurobioides species may have been conducive to this unusually large scale transoceanic dispersal, which the authors propose occurred by "rafting" across oceans on mats of vegetation. While there are other possible explanations for the present day distribution of Amaurobioides species, this study may shed light on how Southern Hemisphere species have come to be distributed across continents.
Related Links PLOS Explore The Early Earth at TerraDaily.com
|
|
The content herein, unless otherwise known to be public domain, are Copyright 1995-2024 - Space Media Network. All websites are published in Australia and are solely subject to Australian law and governed by Fair Use principals for news reporting and research purposes. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA news reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. All articles labeled "by Staff Writers" include reports supplied to Space Media Network by industry news wires, PR agencies, corporate press officers and the like. Such articles are individually curated and edited by Space Media Network staff on the basis of the report's information value to our industry and professional readership. Advertising does not imply endorsement, agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. General Data Protection Regulation (GDPR) Statement Our advertisers use various cookies and the like to deliver the best ad banner available at one time. All network advertising suppliers have GDPR policies (Legitimate Interest) that conform with EU regulations for data collection. By using our websites you consent to cookie based advertising. If you do not agree with this then you must stop using the websites from May 25, 2018. Privacy Statement. Additional information can be found here at About Us. |