A new international study reveals how the evolution of powerful vision was shaped by an improved oxygen supply to the eyes, Mirage News reports.
“Keen eyesight in vertebrates – from fish to birds and mammals – relies on large eyes and thick retinas. Yet the visual process is energetically costly and the high oxygen demand of thick retinas is difficult to meet by the conventional oxygen supply mechanism through blood vessels just behind the retina.”
The study, published in eLife, explored the physiological requirements for the evolution of improved eyesight. The team of researchers, from 15 institutions led by the University of Aarhus and the University of Liverpool, uncovered a pattern of mechanisms to improve retinal oxygen supply.
The study looked at the eyes of 87 animal species and mapped the characteristics of their eyes onto the species’ tree of life. The researchers unraveled the evolutionary history of the eye from a 425 million-year-old extinct ancestor of modern vertebrates to current day animals.