MortalWombat

Opsins (the proteins in photoreceptors that capture light energy) are also found in many organisms that don't have sight (such as some archaebacteria and fungi). That would be the place to start.

Peez

You do seem to be moving the goalposts, but I'll bite. We have to start somewhere, so I will start with an organism that does not respond in any way to what we would call visible light. This is a hypothetical multicellular animal, with a simple nervous system.

The cell membrane in nerve (and other) cells is mainly made up of a bilayer of phospholipids, which is impermeable to ions (electrically charged atoms). There are proteins embedded in the cell membrane which pump ions across, resulting in a difference in electrical potential between the inside and the outside of the cell. There are other proteins embedded in the cell membrane which may provide channels through which ions could move freely, but only when they are opened. There are, for example, some nerve cells with protein channels which will open when they come in contact with certain chemicals. When such a certain chemical, say sugar, comes in contact with the nerve cell, the channel is opened, ions move across the membrane, and a chain reaction ensues which propagates along the nerve towards the brain. When the chain reaction reaches the brain from that nerve cell, it is interpreted as a sweet taste. This is essentially how "taste" works in animals.

The channel protein is made up of a chain of, say, 300 amino acids. The specific sequence of amino acids is coded in the organism's DNA. Changes in the DNA (mutations) may result in a change in one or more of the amino acids. Many of these changes will make no difference in the way the protein functions, but changes in certain critical regions can result in it not working the same way, perhaps not being able to open at all, or staying open all the time, or opening in response to a different chemical. This might prevent the organism from tasting, or allow it to taste something different, or make it think that it tastes sweet all the time. It is also possible that a change will make the protein respond to something else entirely. For example, a changed protein might open in response to heat energy, or light energy. Changing the sequence of amino acids in a protein can change its colour (as evidenced by the different colours that proteins with different sequences have), and different colours are the result of different wavelengths of light being absorbed (that is what colour is). A change in the protein that resulted in that protein absorbing light could easily result in it opening in response the being in light.In a sense, they did (though defining what the "first living thing" was is rather tricky).You seem to be getting at abiogenesis, which is outside of evolution. If you wish, we can assume for the sake of argument that one or more supernatural entities created the first life. This changes nothing about evolution.So, information is something that, by your definition, cannot occur naturally. Such "information" does not appear to exist, so I don't see why we should be concerned with it.No, it is not an increase in "information" by your definition since, as I have described, it can occur naturally.

Peez

Wizardry

Maybe not in the very earliest forms of life, but I'll bet that most everything necessary for sight has variations in creatures that don't see, though they may not be used for sight.

At the most basic level, sight requires only two capabilities that I can think of, the ability to detect light and the ability to react to the environment. The latter is seen in numerious non-seeing creatures that traverse their environment based on heat, salinity and other factors. A lot of introductory biology courses have labs based on evironmental response in primitive animals. Even ameobas can sense enough of their surroundings to successfully envelope whatever food it comes across.

As for light detection, I would be incredulous if there aren't a few proteins, or readily available substances that aren't sensitive to incident photons in any non-seeing animals. I mean, plants base their entire energy system around capturing light energy, so I don't think that light capturing macromolecules are so rare that they couldn't be thrown into the cell membrane and hooked up to the environment detection system. And it only had to happen once in the history of life, so I don't see how it's so incredible.

You may then wonder what the precursors were to both of those systems, but then we're off the subject of photocells, and you see where this is going. The important thing to keep in mind is that the structure used for a new function doesn't have to have been created for that function. Bird wings were originally made for walkiing and just got hollow and covered in feathers.

All those things are really just a variation on a theme, namely response plus some form of detection. And all those forms of detection are either physical or chemical reactions at heart, which is ultimately what drives biological processes. How is an olfactory receptor, which is just a cell that reacts with certain classes of molecules, in function, different from those proteins that react to the release of hormones? In the type of molecule that each bonds to? And isn't that just splitting hairs. Taste is almost the same thing. Hearing is just a matter of detecting the vibration of very small hairs, which is detected by essentially the same kind of nerves that detect the movement of hair on any other part of the body. Add some brain interpretation and some amplifying mechanisms and poof, hearing. And sight is just a matter of finding a molecule that experiences a measureable change upon incident with a photon. Not unbelievable, none of it.

It turns out that quite a lot can be done with proteins, which were in the very first cells.

But how would you deal with pre-existing structures taking on new functions, like arms into wings or forelegs into arms? If function changes but the structure remains essentially the same, does that constitute new information, and it what way?

luvluv

You lost me somewhere. Lets take this in a more step by step fashion. It seems to me you smuggled in a few gigantic leaps in there. Here for example:

It is a pretty large leap to go from something specifically reacting to sugar to something specifically reacting to light.

Also:

How does it being a different color translate into it opening in response to light? That's a big assumption on your part, isnt' it?

No, I'm not getting at abiogenesis. I'd just like to identify what all the precursors to all the senses that we have were in the first organism.

luvluv

Wizardry:

Well, plants are supposedly further down the line. I doubt that the process by which plants convert light into energy is a simple affair, but I defer to MrDarwin on that point. At any rate the fact that plants can do it doesn't really intimidate me much on this point.

I guess I should ask you at this point to a) identify a light capturing macromolecule, b) describe what you mean by "capturing" c) explain what you mean by such a light capturing macromolecule being "thrown into the cell membrane" and d) explain what you mean by it being hooked up to the environment detection system.

Again, it seems like you guys are disguising a LOT of work that mutations are expected to accomplish in language that makes it sound a heck of a lot easier than it is.

Case in point:

The hard part is the adding brain interpretation, "in time" or simeltaneously (I guess) with the mutation of an entirely different part of the body, which then have to correspond with each other.

And did you say "poof"?

As for the last bit of the previous quotation, I was under the impression that the sense of sight developed SEPERATELY in a half dozen or so different species. Is this true? Or is it just the eye itself, and not sight per se, which developed seperately?

I'll have to think about that one.

RufusAtticus

But now you've changed your position. Here is the defination of information you've put forth.

• Information: "the appearance of a new function which cannot be explained as a variation of a previously existing function."

The senses, like everything else in biology don't meet this criteria because in every generation the creatures' senses were simply modified organs/organelles/proteins of their parents'. There is not going to be an exeption for a hypothetical protocell and its immediate decendents. Natura non facit saltum.

Now if you want to define "Information" across longer generational times and allow only partial preexistance, then it is clear that evolution can and has accomplished this.

luvluv

And I'd like to repeat, as I've said before, that if it seems like I'm moving the goal posts this is not because I am shifting definitions in order to win the argument. I'm not well read in ID literature and I don't know their positions or their arguments as well as you folks might think I do. I'm just coming up with definitions off the top of my head and I'm assuming they'll evolve (so to speak!) as the conversation goes on.

You guys have a bad habit of assuming bad faith in every Christian you have a discussion with. I'm not trying to convince you of anything, I'm just trying to have a conversation. I'm not evil, I don't want to miseducate your kids, I'm not anti-science, I don't want to get rid of the seperation of church and state, and I don't disbelieve in evolution because it contradicts the opening chapter of genesis.

I do see what I perceive to be problems with the theory from a laymens point of view, and I'm discussing those with you here. I feel like a lot of you are labeling me the enemy. I'm just a guy with some questions.

luvluv

RufusAtticus:

I understand that this is the assumption. But is this definitionally true, (i.e. is it true simply because it is a logical deduction from Darwinism) or is it known from observation?

If it's known from observation, it should be easy to demonstrate.

RufusAtticus

I understand this, but I was just pointing out your comments were inconsistant with your defination of "information."

RufusAtticus

It is both a logical and empirical result of the known evolutionary mechanisms. Of all the morphological, bioinformatic, and fossil studies we have yet to find any organism which does not show signs of evolution.

That is what the last few posts were trying to do.