Evolution of the eye (science, Article, Greek)

[methylatedghosts]

Ok, this is taken from an article in the regional newspaper here, The Daily Post so I'm just writing exerpts from it and I know that this is a big point some people have to debate against evolution and I wonder if it'd change anything:

"Scientists have traced the origin of the eye back to a transparent blob of living jelly floating in the sea about 600 million years ago. That creature, the distant ancestor of the freshwater animal known as a hydra could only distinguish light from dark."

"It was the precurser of the wildly different, ever more complex eyes of animals today."

"In their research, David Plachetzki and Todd Oakley discovered that a gene called opsin (From the greek word "ops" meaning "eye") exists in hydras but not in sponges - an even more primitive animal."

"They calculated that opsin genes appeared about 600 million years ago, because that's wehen the evolutionary branch that led to modern hydras aplit from the branch that led to sponges. 'We chronicled when and how animals went from lacking opsin genes to possessing opsin genes with different functions.' Oakley said.

"Opsin genes direct the production of light-sensitive proteins, also called opsins, that coat the surface of the hydra especially around the mouth area. The opsin proteins would help these animals tell night from day and perhaps help them find food.

"According to Oakley, the opsin proteins must have evolved from earlier 'signalling' proteins that send chemical messages to other proteins. Signalling proteins exist in all living creatures from the single celled bacteria to humans. "


And those are the most informative bits taken from the article.

Any thoughts?

[rocketman]

Originally Posted by methylatedghosts

Ok, this is taken from an article in the regional newspaper here, The Daily Post so I'm just writing exerpts from it and I know that this is a big point some people have to debate against evolution and I wonder if it'd change anything:


Any thoughts?

Interesting and I think it's no surprise to the 'for' side, but I don't see it changing things much overall. This isn't the first time simple photosensitive cells have been cited as possibly having had a role. Somehow we need to get from these simple elements to what is arguably the most sophisticated tissue in biology, the retina/optic nerve, not to mention the whole interelated eye/brain programmming/optic nervous system, which is ridiculously sophisticated. The image 'processor' is more than a match for modern supercomputers in a much smaller and more efficient package. It's hard to imagine the precise lenses and optics and 'programming' all 'moving forward together'. An 'in-between' system that still functions would be a much more impressive find, but what would it look like?

Those are my thoughts.

[Jayhawker Soule]

Evolution of the Eye

[painted wolf]

Rocketman, you should actually look to the evidence to see the eye evolving.

Bacteria have the ability to detect light, Hydrozoans do it much better by localizing the cells to do so. Turbalarians have done them one up by haveing eye spots, Mollusks run the gambit, from having a retina with no lens to having lenses and quite sophisticated eyes. Even the insect eye is genetically evolved from the same ancestor as ours.

The eye is no big deal for evolution, it is not "irreducably complex" as the Natilus gets by just fine without a lens, and the Turbalarians get by without a retina.

Sorry but the steps on the road to eye devolpment are plain as day if you actually look at the world that looks back at you.

wa:do

[camanintx]

Originally Posted by rocketman

It's hard to imagine the precise lenses and optics and 'programming' all 'moving forward together'.

Why do so many people who doubt evolution have difficulty imagining how the process works?

[Terrywoodenpic]

Originally Posted by camanintx

Why do so many people who doubt evolution have difficulty imagining how the process works?

Because mostly they do not understand or study the biological sciences.
nor indeed any science that might have an impact of the origin of the world.
Why would they see the need to study any thing to which they know the answer, and which is the irrefutable word of God?

[rocketman]

Originally Posted by Terrywoodenpic

Because mostly they do not understand or study the biological sciences.

That does not apply to me. The view I have is valid precisely because I study these things, to my mind anyway. But each to their own.

[rocketman]

Originally Posted by painted wolf

Rocketman, you should actually look to the evidence to see the eye evolving.

I have. And yes, I'm well versed in the principles of mutation and selection and so-called gradualism and punctuated equilibrium and everything in between. All of the 40+ independendant evolutions of various types of eyes are all pretty sophisticated interelated systems (the eye itself being but one element). I'm not ashamed to say that I find it next to impossible to believe that these things can come about 'bit by bit'. And yes, I'll repeat that I am well versed in the principles of mutation and selection. It's not in some people's nature to 'infer' across gaps. I can't help the way my mind weighs things, and it's got nothing to do with religion. I don't think this latest finding will do much overall.

[Jayhawker Soule]

Originally Posted by rocketman

I'm not ashamed to say that I find it next to impossible to believe that these things can come about 'bit by bit'. And yes, I'll repeat that I am well versed in the principles of mutation and selection.

I find it remarkable that someone so well versed would come out with: "An 'in-between' system that still functions would be a much more impressive find, but what would it look like?"

[rocketman]

Originally Posted by Jay

I find it remarkable that someone so well versed would come out with: "An 'in-between' system that still functions would be a much more impressive find, but what would it look like?"

Why?

I'm not saying it didn't happen, just that I find it hard to believe. Because, for example, lots of things have to happen, not just changes to the eye. Things like the architecture of the eye socket (blood vessels, bones), major biochemical changes, major neurological changes (probably the most sophisticated ever). Each step along the way needs to be able to use these linked systems to see, assumedly with greater ability as time moves forward. I look at how minute changes in optical systems extant today disable those systems and I'm even less convinced.

Nilsson and Pelger's model calls for a constant mutation rate for 300,000 years straight, a cute guess if there was ever one. Their light-sensitive patch is said to gradually become a focused lens but there is no explanation of how the system as a whole could support the altered optics at all the points along the way. In the end one has to accept that there were in-between animals with light-sensitive systems co-existent with early optical definition systems; and tha