The evolution of the eye: Platynereis, trilobites, Anomalocaris and Helix. Dissemination 102nd
In disclosure No. 13 we wrote: The Dras. Tessmar-Raible and Snyman in 2004 isolated sensitive opsin to light in the ganglion cells of the marine annelid Platynereis dumerilii (living fossil with a history of 600 million years), very similar to the opsin structure existing in the cones and canes eyes of vertebrates.
This way it establishes the biochemical relation between the first cranial nerve ganglia of the nervous system of marine annelids, and the first cranial nerve ganglia of the nervous system of vertebrates (eyes). From this primitive annelids models, insects and vertebrates have evolved independently resulting in different eyes and nervous systems. However, the model remains identical: a chain of primitive nerve ganglia that have specialized even maintain the connection between them (Strung chain or rope ladder). Although the current annelids such as the earthworm (Lumbricus terrestris), maintain this structure of double ganglion, connected together and with the next pair in the next ring node, the first eyes in its current concept, have been observed in trilobite fossils ages 540 million years.
From the eye Platynereis (-600 m) which accumulates, opsins, photosensitive pigments, passing into the eye of Trilobites.
(-540 M) up to modern eyes flexible (snail), in the eyes of circular view (dragonflies) and eyes of mammals (with selective views of certain colors) evolution and natural selection have led to different eyes.
To this list of fossil eyes we can incorporate eyes of Anomalocaris, discovered in rocks 515ma, an animal related to the current arthropods, which had eyes of 3 cm, with numerous lenses (up to 16000) distributed as follows: largest in the center and smaller in the periphery.