|
. | . |
|
by Brooks Hays Kumamoto, Japan (UPI) Dec 24, 2014
Rods and cones, the two main photoreceptor cells, are vital to human sight -- converting visible electromagnetic radiation into information our brains can use. And it turns out, the biological technology has been around for more than 300 million years. A team of international scientists, led by researchers at Japan's Kumamoto University, recently discovered and analyzed an ancient fossilized fish boasting a perfectly preserved eye. Inside the ancient eye, researchers found rods and cones. "Rods and cones are not usually preserved, because these soft tissues are more fragile," lead study author Gengo Tanaka, a paleontologist at Kumamoto, told Live Science. Rods and cones are sensitive to color and also help perceive fine detail and rapid changes. Rods are more sensitive to light than cones, but are not sensitive to color, and are responsible for peripheral and night vision. The eye (and the fish that hosts it) was discovered in Kansas, but it is currently housed in the National Museum of Nature and Science in Tokyo. These ancient rods and cones helped a type of fish called Acanthodes bridgei, the last known common ancestor of modern jawed fishes -- both bony and cartilaginous species -- including barracudas and sharks. The same photoreceptor cells and phototransduction capabilities that allow the human brain to recreate the visual world, also helped A. bridgei -- which grew no more than four inches in length -- navigate the shallows, locating prey and avoiding predators. Because rods and cones are so delicate, scientific have had a difficult time painting an accurate picture of the evolution of eyesight. But the latest discovery suggests modern eyesight has been around for at least 520 million years, when A. bridgei first appeared on the fossil record. The study was published this week in the journal Nature Communications.
Related Links Explore The Early Earth at TerraDaily.com
|
|
The content herein, unless otherwise known to be public domain, are Copyright 1995-2014 - Space Media Network. All websites are published in Australia and are solely subject to Australian law and governed by Fair Use principals for news reporting and research purposes. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA news 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 All images and articles appearing on Space Media Network have been edited or digitally altered in some way. Any requests to remove copyright material will be acted upon in a timely and appropriate manner. Any attempt to extort money from Space Media Network will be ignored and reported to Australian Law Enforcement Agencies as a potential case of financial fraud involving the use of a telephonic carriage device or postal service. |