Posted on 07/23/2018 7:13:55 PM PDT by Simon Green
Jellyfish and their kin have no brains and make do with rudimentary nervous systems. But an analysis now shows that these simple sea creatures evolved eyes multiple times, transforming basic precursor cells into a wide range of useful visual systems.
Using DNA sequences, Natasha Picciani and Todd Oakley at the University of California, Santa Barbara, created an evolutionary tree of Cnidaria, the large grouping or phylum that includes jellyfish, sea anemones and corals. They then incorporated information about the species light-sensing abilities. The team found that the common ancestor of todays cnidarians could probably detect light and dark, but lacked specialized eyes.
Among the descendants of that eyeless ancestor, at least eight separate evolutionary events gave rise to eyes, including some with lenses and others with simple structures called eye cups. At least two major types of cnidarian eye use different molecular systems for light detection, suggesting that different lineages co-opted ancestral genes independently to enable vision.
(Excerpt) Read more at nature.com ...
Sign them up for Democratic Socialists of America.
Hogwash. Mere observations, no experimental proof can duplicate this. Nonsense.
nope. God used His mind full of all sorts of options in making each kind and variations in each kind. Lots of eye, ear, body shapes etc etc for Him to pick from in creating each living thing on this planet past, present and future.
Here you have an early car without a bumber
After some failures
It mutated into a car with 4 wheels
Bumpers provided an evolutionary advantage. Some bumbers evolved to be light weight thin metallic strips others evolved completely differently.
And yet they mass migrate to certain beaches at low tide and FULL MOON to mate.
True, but the brain is rarely involved with sex as we all know :-)
Sounds like human teenagers...no brains either...
It’s amazing how living creatures can be windows into the distant past.
” including some with lenses and others with simple structures called eye cups “
Except for Cyclops....
” Lots of eye, ear, body shapes etc etc for Him to pick from “
Who provided Him with the selections to pick from?
Bookmark.
Why honey, don't you know? He got a hankering for a brand new updated eyeball, so he went to the big Evolution Box Store some forty miles away in the big city of Slime Pit. He picked out the model he wanted from thousands upon thousands of choices. It took quite some time, with so many selections to choose from. He didn't mind the time, nor the work, because he was very set on seeing. He finally choose the XYP model, which saw everything quite clearly.
Now the next thing was to find a skeletal model adjusted to fit his wonderful new eye just right. He tried on many skeletal models, but finally settled on the one he liked best. Thankfully it fit perfectly.
It took a long time, too, because he also had to find all the many, many right accessories to go with his new eyeball, and skeletal model. He knew without all the right accessories all his great effort would be for absolutely nothing. It was all quite an exhausting endeavor, but when he was finally all finished he was exceedingly pleased with his new eyeball.
"He was last heard saying, while toasting to his new eyeball with all of his many still sightless old buddies, "Here's to seeing you!".
Interesting? But why did he pick the model with the inverted photoreceptors for us?
I guess he was known to have suffered from a bit of deflexia. He tended to get things confused, turning them upside down, or inside out and sometimes backwards. It appears that he thought it a harmless mistake, so he didn’t bother to fix.
This topic was posted , thanks Simon Green.
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