3 edits
Originally posted by KellyJay…No it would not give the animal the ability to tell light from dark, unless
No it would not give the animal the ability to tell light from dark, unless
there was some means of translating that information into a useful
piece of data. Light sensitive means what to you, a reaction to light,
and how would that be useful, does it focus on this new piece of info
and therefore get transfixed into a position that could cause it to mis ...[text shortened]...
be helpful and not harmful, what animal got this light sensitive spot?
Details please.
Kelly
there was some means of translating that information into a useful
piece of data….
So what is stopping a nerve from transmitting useful information from a light sensitive patch to the brain? -after all -this is exactly what biologists have discovered happens in certain species of worms that live today.
I got this quote from http://www.geocities.com/CapeCanaveral/Hangar/2437/halfaneye.htm
But the relevant part to this quote to this discussion is the last sentence:
“So, how can an eye evolve step by step? Well, we start with an eyespot, a small spot on the skin of a small invertebrate that contains pigments (and nearly ALL organisms have pigments in their skin). Some pigments (such as rhodopsin) are light-sensitive and produce chemical changes in the presence of light. Hence, an organism with a crude "eyespot" like this would have the selective advantage of telling light from dark -- all with nothing but a patch of pigmented skin. This is the sort of eye that many unicellular organisms and some very simple multicellular organisms like worms have.”
Note the last sentence above: it suggests that certain simple worms that are living today have a light sensitive patch that, obviously, transmit useful information to the brain.
Also, from the same website, I got:
“And there we have an eye, produced step by step, each with just small changes, each change being fully functional and a selective advantage for the organism that has it.
And how do we know that each of these steps is not only possible, but actually works? Because ALL of them STILL EXIST today in various organisms.” (my emphasis)
… Light sensitive means what to you, a reaction to light,
and how would that be useful, does it focus on this new piece of info
and therefore get transfixed into a position that could cause it to miss
out on the food supply it is near, does it run away from this new piece
of information to avoid the food supply it is near by, how exactly does
this sensitivity work? …
Obviously a “worm” (if that was what it was) which had the first mutation that gave it the first light sensitive patch didn’t have the instinct to respond to the information in the most beneficial way because evolution of the best instinct must have occurred AFTER the mutation for the light sensitive patch. In the mean time, the worm could have “learned” within its lifetime to associated, say, light for food, or maybe dark for danger etc by what is called “Classical conditioning”:
http://en.wikipedia.org/wiki/Classical_conditioning
And, specifically for classical conditioning for worms:
http://www.sciencedirect.com/[WORD TOO LONG]
This wouldn’t have been as good as blind instinct because the worm wouldn’t get the full benefit from it until it has learned it but, never a less, it would have still given it an advantage in survival and then later blind instinct would have inevitably evolved that would have made the worms immediately give a good response because that would give them the survival advantage of not having to spend time learning it first sometime after they are born.
…what animal got this light sensitive spot?
…
A number of species independently evolved to have it -and some still have it today.
Originally posted by EladarCan you support that claim.
With the case of the eye, the specialized parts of the eye are not useful unless the other specialized parts are already in place. Therefore natural selection does not explain how these specialized parts evolved into what we now know as the ability to see.
Lets suppose that each specialize part evolved in sequence (that is not the only possibility, but lets rule it out first).
Please list all the specialized parts.
Is it your claim that if we take away any one of those parts then the eye will cease to function?
If I can show that one of the parts in your list is not required, will you accept that your original argument is false?
Originally posted by BadwaterThe bottom line is our eyes and eyes of say, octopus, or eagle came by different routes of evolution, not by any intelligent design or creation tale which is why our eyes are so different from other animals.
I would disagree - it is designed well for its purposes. The eye is more than a function of blood vessels. For example, our light perception at night is about as good as an owl's and it's not taking up a huge proportion of the head to allow for greater resolution. An owl's takes up proportionally much, much more space.
There are many other examples. I'm ...[text shortened]... g there is any credibility to Intelligent Design; I merely take exception to your statement.
Our position is, if the creationists are correct, humans being the pinnacle of creation ( a laughable position) , then their god would have made us the best way it could have. Since their god created octopi and eagles and whales and so forth, it could have encorporated the best eye design in human eyes, otherwise in the case of eyes, humans are not the pinnacle of creation, but inferior to those other animals so the so-called intelligent designer wasn't so intelligent. That is the thrust of our position.
Originally posted by KellyJayA large variety of cells are sensitive to light. By that I mean that they react in some way to light.
No it would not give the animal the ability to tell light from dark, unless
there was some means of translating that information into a useful
piece of data. Light sensitive means what to you, a reaction to light,
and how would that be useful, does it focus on this new piece of info
and therefore get transfixed into a position that could cause it to mis ...[text shortened]...
be helpful and not harmful, what animal got this light sensitive spot?
Details please.
Kelly
Most plants make food from light - that is a reaction. Futher, they grow towards the light, turn their leaves towards the light, open their flowers based on the time of day or night etc.
In animals, light sensitivity is a bit less common, but still very prevalent. My skin is sensitive to light. It manufactures vitamin D from sunlight and manufactures melanin if exposed to too lots of sunlight.
My skin also contains nerves that can sense changes in the skin, including touch, changes in temperature etc. It would be a relatively minor change for the nerves to start sensing a change in the levels of Vitamin D manufacture.
- Joined
- 07 Jan 08
- Moves
- 34575
Originally posted by sonhouseYour eye did not come by a different route of evolution than that of an eagle. It came by the same route. Neither the eagle eye nor the human eye is 'superior'. The eagle has better resolution but if it loses an eye it's a dead bird; it cannot survive. A human can survive and do well without having to have two eyes. How is the eagle eye superior in that circumstance?
The bottom line is our eyes and eyes of say, octopus, or eagle came by different routes of evolution, not by any intelligent design or creation tale which is why our eyes are so different from other animals.
Our position is, if the creationists are correct, humans being the pinnacle of creation ( a laughable position) , then their god would have made us th ...[text shortened]... o the so-called intelligent designer wasn't so intelligent. That is the thrust of our position.
Originally posted by Andrew HamiltonJust so I know this is where we are starting, a brain and nerves were
[b]…No it would not give the animal the ability to tell light from dark, unless
there was some means of translating that information into a useful
piece of data….
So what is stopping a nerve from transmitting useful information from a light sensitive patch to the brain? -after all -this is exactly what biologists have discovered happens i ...[text shortened]...
…[/b]
A number of species independently evolved to have it -and some still have it today.[/b]
in place where the eye appears? Anything else?
Kelly
1 edit
Originally posted by Andrew HamiltonA number of species independently evolved to have it -and some still have it today.
[b]…No it would not give the animal the ability to tell light from dark, unless
there was some means of translating that information into a useful
piece of data….
So what is stopping a nerve from transmitting useful information from a light sensitive patch to the brain? -after all -this is exactly what biologists have discovered happens i it first sometime after they are born.
…what animal got this light sensitive spot?
…
[/b]Okay, so whatever the process for an eye to begin is so easy to do
it can happen independently in several species. This should make
the path towards seeing easy. I'll line up my questions for you.
Kelly
Originally posted by KellyJayWhich question does this answer? The 'Why' question?
Both eyes reside in completely different environments, inside forms
that are completely different too, how they would react over time
in my opinion would be, different.
Are you saying that terrestrial environments benefit from having blind spots while aquatic
environments benefit from not having them?
Or is this an answer to the 'How' question?
Are you saying that because we're terrestrial, our nerve fibers moved from behind the retina
to in front of it, creating blind spots?
Whichever answer it is, can you substantiate it with, well, anything that constitutes evidence, even
if it's controversially accepted?
Nemesio
Originally posted by KellyJayI can't understand your sentence fragments, stop smashing the keyboard with your fist.
What this discussion is, has one group of people saying they think
one design is better than another, that promotes ID issue how? You
think one is better than another, one that works in a completely
different enviroment! I'm suppose to think that should give me
cause to doubt what we humans have is less than it should be when it
gives us what we need f ...[text shortened]... e I'd say you have a valid argument, since that is
not the case, I say you have none.
Kelly
The argument that Nemesio is making is that if an Intelligent Designer designed everything, the Designer would design things intelligently. This stems from the Christian claim that God is everywhere (omnipresent), all knowing (omniscient) and all loving (omnibenevolent). If God is omniscient, why did God wire the human eye wrong?!? The common response is "God gave every creature the eye they need." If we had a list of needs, we could test this hypothesis. However, Creationists claim that all needs are satisfied without any discussion, as per the claim "God gave every creature the eye they need." By removing any counter-claim from possible debate, Creationists have changed the claim "God gave every creature the eye they need" from a hypothesis to a tautology. Unfortunately, tautologies don't tell you anything. All the Creationists really do is remove the only possible tool for determining the veracity of their own claim from discussion in a fit of obstinacy.
Originally posted by sonhouseThis isn't quite right, sonhouse. The clade from which humans and eagles inherited their camera-like
The bottom line is our eyes and eyes of say, octopus, or eagle came by different routes of evolution, not by any intelligent design or creation tale which is why our eyes are so different from other animals.
eyes is the same, and it's an ancient clade indeed (going back to fish).
The cephalopod camera eye arose from 'convergent evolution;' there is no ancestor in common
with them and eagles/humans that have eyes.
Nemesio
1 edit
Originally posted by KellyJayCome off it KellyJay, that post was a killer! It demonstrates a possible path to the eye, and gave evidence of intermediary steps that still exist today!!! Your claim that the human eye could not have arisen through natural selection has been DEBUNKED!!!
[b]A number of species independently evolved to have it -and some still have it today.
[/b]Okay, so whatever the process for an eye to begin is so easy to do
it can happen independently in several species. This should make
the path towards seeing easy. I'll line up my questions for you.
Kelly[/b]
2 edits
Originally posted by Badwater…Your eye did not come by a different route of evolution than that of an eagle.….
Your eye did not come by a different route of evolution than that of an eagle. It came by the same route. Neither the eagle eye nor the human eye is 'superior'. The eagle has better resolution but if it loses an eye it's a dead bird; it cannot survive. A human can survive and do well without having to have two eyes. How is the eagle eye superior in that circumstance?
If you read what sonhouse said carefully, he does not seem to imply that this is not true.
In any case, we and eagles share a common ancestor that had eyes but then that species split into two or more groups and the eye farther evolved in each group (especially the one that was the ancestor for eagles) -one group leading to us and the other to eagles -so it is still correct to say that the evolution of the eyes in each “came by different routes of evolution” to a limited point although, of course, if you go back far enough, the routes join up at the ancestor that is common to both.
Perhaps it is better to say that they came from “partially different routes of evolution” in this case.
…Neither the eagle eye nor the human eye is 'superior'.….
Neither I and, I am sure, sonhouse, believes that there is such thing as “superior” in an absolute non-comparative sense; obviously what we mean by “superior” in this very narrow context is relative or comparative better design -I.e. when COMPARING the DESIGN of an eagle’s eye with that of a human, one design is clearly better than the other (and one clearly has obvious design flaws).
… A human can survive and do well without having to have two eyes. How is the eagle eye superior in that circumstance?
…
-it isn’t -but it is when both the human and the eagle DO have their eyes (and most eagles and humans do) partly because eagle eyes don’t have blood vessels in front of their retinas and partly because they have better optics for focussing (a double lens arrangement). There is no doubt that a human can survive without eyes just as there is no doubt that a human can survive with eyes of a flawed design but surely it is better for the human to have has eyes with NO obvious design flaws than to have eyes WITH obvious design flaws? -a human with eyes with no obvious design flaws would also often have a better chance of surviving when danger threatens depending on the kind of threat and whether or not good eye-sight helps.
- Joined
- 07 Jan 08
- Moves
- 34575
2 edits
It's not the placement of the blood vessels so much that allows birds like an eagle to see better that the human eye. It is that they have a very high density of cones. Additionally, each of the four types of cones (red, green, blue and UV receptors) has an associated oil droplet to filter or enhance certain wavelengths, giving the capacity to see more colors than we do and to be able to more easily distinguish such things as brown grass from brown fur from afar.
To just look at blood vessels is, pun intended, myopic. There is so much more than just the placement of the blood vessels that is supposedly making any eye superior or inferior to another.
Mind you, I don't think intelligent design has a place in science. But those both for and against intelligent design have to look farther (pun again intended) than blood vessels to give credence to or discredit their arguments. What is going on with eyes is far more complicated than merely the placement of blood vessels.
- Joined
- 07 Jan 08
- Moves
- 34575
Originally posted by EladarOf course. But at some point we run into the insurmountable wall of I Don't Know and both sides of this particular debate seem completely incapable of saying I Don't Know.
[b]Mind you, I don't think intelligent design has a place in science.
Does science have a place in trying to discover the origins of life and the nature of our existance?[/b]