Figure 1: Lithograph of Charles Robert Darwin, aged 40, in 1849, by Thomas Herbert Maguire. Image: Wellcome collection
Since vision plays such an important part in everyday living, it is relevant to reflect on the evolutionary processes involved. The area of vision system evolution has been of particular fascination for a wide range of scientists – especially biologists, zoologists, geneticists and palaeontologists – and where an extensive literature is available on the subject, including the diverse vision systems developed across current and extinct species.1,2
In the expansive world of the biologist, the human eye is merely a single detail within a diverse lineage of sighted species. The picture emerging of the evolution of vision, however, is by no means static as new fossil evidence emerges and the genomes of species of interest are decoded to establish evolutionary trajectories.