Evolution: new evidence of pre-planning (Evolution)

by David Turell , Thursday, April 08, 2021, 23:21 (1323 days ago) @ David Turell

The eye brain circuitry origination started in the seas:

https://phys.org/news/2021-04-discovery-literally-textbook.html

"The network of nerves connecting our eyes to our brains is sophisticated and researchers have now shown that it evolved much earlier than previously thought, thanks to an unexpected source: the gar fish.

"Michigan State University's Ingo Braasch has helped an international research team show that this connection scheme was already present in ancient fish at least 450 million years ago. That makes it about 100 million years older than previously believed.

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"This work, published in the journal Science on April 8, also means that this type of eye-brain connection predates animals living on land. The existing theory had been that this connection first evolved in terrestrial creatures and, from there, carried on into humans where scientists believe it helps with our depth perception and 3D vision.

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"In a zebrafish, each eye has one nerve connecting it to the opposite side of the fish's brain. That is, one nerve connects the left eye to the brain's right hemisphere and another nerve connects its right eye to the left side of its brain.

"The other, more "ancient" fish do things differently. They have what's called ipsilateral or bilateral visual projections. Here, each eye has two nerve connections, one going to either side of the brain, which is also what humans have.

"Armed with an understanding of genetics and evolution, the team could look back in time to estimate when these bilateral projections first appeared. Looking forward, the team is excited to build on this work to better understand and explore the biology of visual systems.

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"'We're finding more and more that many things that we thought evolved relatively late are actually very old," Braasch said, which actually makes him feel a little more connected to nature. "I learn something about myself when looking at these weird fish and understanding how old parts of our own bodies are. I'm excited to tell the story of eye evolution with a new twist this semester in our Comparative Anatomy class.'" (my bold)

Comment: the bold is certainly in support of pre-planning