A new study has traced the evolution of vision among the humans.”Opsin, the light-sensitive proteins key to vision, may have evolved earlier and undergone fewer genetic changes than previously believed”,says the latest report in the Science Daily.
The report based on the study from the National University of Ireland Maynooth and the University of Bristol published October 29 in Proceedings of the National Academy of Sciences (PNAS),stated that the researchers used computer modelling to provide a detailed picture of how and when opsins evolved.
It “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.”
The same report points out that Dr Davide Pisani of Bristol’s School of Earth Sciences and his 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”,adds the report.
The report quotes Dr Pisani sayng: “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.”