by Staff Writers
Bristol UK (SPX) Oct 31, 2012
The study, which used computer modelling to provide a detailed picture of how and when opsins evolved, sheds light on the origin of sight in animals, including humans. The evolutionary origins of vision remain hotly debated, partly due to inconsistent reports of phylogenetic relationships among the earliest opsin-possessing animals.
Dr Davide Pisani of Bristol's School of Earth Sciences and colleagues at NUI Maynooth performed a computational analysis to test every hypothesis of opsin evolution proposed to date.
The analysis incorporated all available genomic information from all relevant animal lineages, including a newly sequenced group of sponges (Oscarella carmela) and the Cnidarians, a group of animals thought to have possessed the world's earliest eyes.
Using this information, the researchers developed a timeline with an opsin ancestor common to all groups appearing some 700 million years ago. This opsin was considered 'blind' yet underwent key genetic changes over the span of 11 million years that conveyed the ability to detect light.
Dr Pisani said: "The great relevance of our study is that we traced the earliest origin of vision and we found that it originated only once in animals. This is an astonishing discovery because it implies that our study uncovered, in consequence, how and when vision evolved in humans."
Paper: 'Metazoan opsin evolution reveals a simple route to animal vision' by Roberto Fueda, Sinead C. Hamilton, James O. McInerney, and Davide Pisani in PNAS.
University of Bristol
Explore The Early Earth at TerraDaily.com
|The content herein, unless otherwise known to be public domain, are Copyright 1995-2014 - Space Media Network. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA Portal 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. 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. Privacy Statement|