cool book

Initial choices? Who made those?

How did the retina of our ancestor species get all redesigned and inverted against a negative selection gradient?

Do you believe in evolution? In natural selection?

Guess not. Few people actually do.

I'm asking a simple question: why would evolution go through a lot of steps to create an inferior eye?

Right. That's Darwinism, random variation and selection.

Stuck in a local minimum? That means that evolution just kept making our eyes worse until it settled on really bad.

Of course, there is another explanation.

Yes. Human vision was good enough for the purpose, so the pressure was less than on other things.

If not, there would have been much Darwinist Depletion and random variation with jumps until something, anything worked. Just like those hapless bacteria climbing antibiotic gradients in the time lapse movies I posted earlier.

Joe Gwinn

Good enough? Is there a threshold for that, where selection stops?

The creatures with superb vision will extinct the creatures with good-enough vision.

So many people refuse to believe in evolution.

Loose, ambiguous, and incoherent specification of the test regime, of course. The problems that DID get caught, were patched up (in ways that allowed or encouraged different bugs).

Maybe in the next patch, Windows will finally be fixed. More likely, though, is that it will evolve into something complex, perhaps even deserving the descriptor 'bad', though that seems to be a childish and ambiguous nomenclature, consistent with an ambiguous and incoherent Windows specification...

OK, not you.

There is no threshold per se. It's more a matter of focus. Everything evolves, but the rates differ depending on where the selective pressure lands most intensely.

Not necessarily. For instance, better vision requires more brain mass to process. Likewise better olfaction. The question becomes what to spend the nerve-tissue budget on. It's not a trivial question - humans spend about 25% of their total calorie budget running the brain.

Given the success of critters with big brains but so-so vision and sense of smell, brain size seems to be the more important. Maybe because it led to the invention of spears and the like. Not to mention language.

Yes. But evolution don't care.

I suppose the next frontier is how life evolved in the first place, from non-living things. Even if we figured it out, I don't know how one could prove it. The experimental timeline well exceeds Human patience.

Joe Gwinn

Because it's better than nothing, and because it's complex a small mutation in the right direction would make it worse.

Ramdom mutation (Anthormopomorphised).

That hasn't happened it's still sub optimal.

I can't see how you're in any way qualified to make that sort of guess.

Yes, of course. Some designer made it all. And some anterior designer designed the designer, and so on ad infinitum. Easy.

Jeroen Belleman

A followup: Syntenic Dotplots show the effects of genome cut-and-paste most clearly:

.

There are many examples on the web.

Joe Gwinn

Because sensing light is useful. and somethign that works badly will get improved upon, however if it starts on the wrong path it will not lead to the best solution.

Local optimum, depending on how you measure it's a mimima or maxima. Are you attacking him for a poor choce of word, or are you really that unimformed?

There's no shortage of bad explanations.

No, the explanation is that our eyes did evolve to be better, and the inverted retina is better.

People want to cite the inverted retina as a bad design, so they can mock "intelligent design." But the argument trashes evolution even worse.

Why? Chance is chance.

If you believe such a watchmaker, then that is the consequence.

No and yes, respectively.

It seems improbable to me that you choose not to understand natural selection, but there you are.

Demonstrably false; visible to anyone with a high-tech scalpel and microscope or the ability to look at the misbehavior in the examples I gave (michalebach.de)

They didn't.

They didn't.

Google human retina inverted

It clearly isn't. But there was never a one-step-at-a-time route to a non-inverted retina.

It is clearly bad design, and trashes the idea of an intelligent designer.

How? Further down this thread you've suggested googling "inverted retina" which throws up this

On Saturday, 20 March 2021 at 14:15:25 UTC-7, snipped-for-privacy@highlandsniptechnology.com wrote: ...

Yes - the better version will only become more prevalent if it helps its genes prosper.

Only if it gives them a reproductive advantage. Good enough means "good enough". Any improvement doesn't gain the organism anything significant. Human vision isn't as good as many other animals but it presumably didn't give enough advantage to become better.

Many evolutionary improvements are not worth their extra cost so they never become prevalent.

Even such things as human intelligence is a very costly benefit - other organisms may not have found the extra energy requirements worth it.

You're right, many people don't understand it.

Or just that human eyes are 'Good Enough' and any changes didn't result in any reproductive advantage so they didn't gain hold.

Difficult to see how you arrive at that conclusion.

That exactly Suzana Herculano-Houzel's hypothesis. The other great apes didn't scale up their brain in proportion to the body size in the way we did.

We probably invented cooking so that we could digest the extra food our brains consumes fast enough to give us enough free time to find the extra food we needed to feed it.