Evolution likes local maxima. Getting out of them is difficult. That's what the OOP meant with "evolution was powerless to correct it".

Getting out of local maxima means you first have to go with a worse setup until you get to a new, better local maxima. That's why evolution doesn't really do that all that often and instead prefers small optimizations.

(I use "like" and "prefer" not to say that evolution has goals or emotions, but to say that that's what the "algorithm" of evolution leads to.)

That explains the platypus.

Or as an old classmate told me in college: the platypus is proof that nature has a sense of humor.

Ugh that drives me crazy. The human eye is a perfect example of observable evolution. Organisms exist with every stage of eye development, from a photosensitive spot to a more advanced convergent evolution of our eye. And the human eye is poorly designed for it's current use, resulting in a significant percentage of people requiring corrective lenses.

Clearly this means God’s chosen are the cephalopods.

As someone with chronic back pain, eyes are the least of my issues with creationists theories

Cephalopod precursors evolved eyes and then brains developed from the eye so their eye is structured correctly.

Vertebrate precursors evolved the brian first and the eye evolved out the brain as a sensory stub. So it's upside down and inside out like in picture.

The nerve cluster goes through the back of the eye splits and folds back to end in light receptors. Light hase to go through the nerves before hitting the sensor.

There is even a reflective layer after the sensors that gives the sensors a second chance at picking up the light. This is what causes the red eye or green eye you sometimes see in flash photography.

It would require a genetic rebuild to fix this and the intermediate steps evolution usually use would be so disadvantageous they are selected against. So the right combo of mutations to give us a working octopus eye is VERY unlikely to happen.

Octopuses don't have a dead spot in the eyes I guess

Scallops, oysters, mussels and clams have anywhere between 40 and 200 eyes. https://en.wikipedia.org/wiki/Mollusc_eye

This is just saying that the glial cells help make this less bad than it could be, no? Nothing about why neurons behind receptors would be worse

I have heard the theory that it evolved this way for higher UV protection that was not needed in underwater organisms. Curious if it was really that much of a competitive advantage though.

Edit: okay more recent studies show not so much protection but basically filtering and redirecting light so out eyes can see better color on land. See this comment: https://lemmy.world/comment/18892927

It's way too late at night for all those directions, somehow ended up creating my own blind spot by sticking my thumb in my bum.

the brain fills in the gap

To expand on this, current leading theory (predictive processing) says that brain first generates a visual image then confirms it with inputs and if there's no input to confirm/deny the halucination it's just accepted as is. So we can have a whole load of blind spots in all of our sensors and continue functioning rather well with an ocassional artifact.

• just one brain

Well

It doesnt