![\"\"](\"https:\/\/iristech.co\/wp-content\/uploads\/2017\/10\/eye-evolution-infographic.jpg\")
<\/a>\n
The origins of vision is a widely debated subject, since genetic relationships between early animals capable of sight are inconsistent. A team of researchers has conducted an extensive computer analysis that tests every proposed hypothesis on the origin of vision to date, and found a common ancestor dating from 700 million years ago. Their findings suggest vision evolved much earlier than previously thought.<\/p>\n
Opsin is photosensitive protein which holds the key to developing optical vision. These vital components trap light in the eyes\u2019 pigments, however when they first evolved has been always a puzzling question for scientists.<\/p>\n
Dr Davide Pisani of Bristol\u2019s Schools of Biological Sciences and Earth Sciences and colleagues at NUI Maynooth performed a computational analysis of 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\u2019s earliest eyes.<\/p>\n
With this data at hand, the researchers were able to construct an evolutionary timeline of opsin, which eventually lead them to the point of origin \u2013 a common ancestors to all groups appearing some 700 million years ago. The first opsin originated from the duplication of the common ancestor of the melatonin and opsin genes in a eumetazoan (Placozoa plus Neuralia) ancestor, and an inference of its amino acid sequence suggests that this protein might not have been light-sensitive.<\/p>\n
Despite being consider blind, the opsin protein underwent key genetic changes over the span of 11 million years that conveyed the ability to detect light.<\/p>\n
\u201cThe great relevance of our study is that we traced the earliest origin of vision and we found that it originated only once in animals,\u201d says Dr Davide Pisani.<\/p>\n
\u201cThis is an astonishing discovery, because it implies that our study uncovered, in consequence, how and when vision evolved in humans.\u201d<\/p>\n
Findings were published in the journal PNAS. Below you can find a very interesting infographic published by Voltier Creative which explains how eyes evolved.<\/p>\n