Originally posted by amannionThe issue isn't resolved by items being internal or external, the point
Clearly we don't have all of the steps or the explanations for the steps.
It's a little like building a model to describe the formation of the solar system. I know what currently exists and so any model I build must be able to describe how to get to this current state.
With light sensitive cells, I know they exist - I'm viewing this screen with millions o ...[text shortened]... confer advantage and so become common, others to confer disadvantage and so be weeded out.
to the whole thing was when you get a new device, if the system is not
setup for it, it will not work. There are plenty of computer parts that
can be either internal or external and both require drives and the
proper wiring.
I'm not debating if light sensitive cells exist or not, I'm talking about
the formation of the eye and the beginning of the process. I have no
doubt that with light sensitive cells placed within a system that has all
the necessary items in it so the system can see gives a great advantage
to those that have them over those that do not. That is not the debate,
it actually hinders the debate as far as I can tell too since so many just
assume seeing for the first time is better than not seeing, they do not
take into account what could go wrong as well, it is always an
advantage to get this light sensitive patch, as you yourself proclaimed
too. That is comparing a fully formed system that has all the pieces in
place and applying that standard to something else completely different.
I am also working under the assumption evolution is a fact, but I do
not accept everything that everyone gives evolution credit for, it has
to earn credit before I want to give it. Saying evolution is a fact and
evolution had to have started at a certain point automatically assumes
all of these things must have happened, to doubt it is to doubt the theory,
than you would run the risk of being called anti-science. When in fact
you would just be questioning the finer points of a theory, which I
always assumed was a good thing.
I pointed out in another post you do not get to add parts piece meal
and I gave you reasons why that would be harmful. The only reason
you’d just accept that without much support is that you assume
certain truths about evolution that cannot be backed up, but must be
accepted as truth nonetheless.
Kelly
Kelly,
Do you accept my following claims:
1. Many cells are light sensitive for reasons other than sight. Eg most plant cells (produce energy), human skin cells (manufacture vitamin D).
2. Most organisms have some form of transmiting messages from one part of thier body to another. Most animals do so rapidly (a consequence of a mobile lifestyle). Such a mechanism is not dependent on sight.
If you do, then why do you claim that more than one new feature is required for sight aquisition? In my opinion, all that is required is behaviour change, to take advantage of systems that already exist, followed by enhancements to those systems as a result of the preasures exerted by the environment after the behavoural change.
Just a little research would turn up a whole host of creatures that can and do react to light without infact having eyes.
For example jellyfish. I just looked them up on Wikipeadea and found this:
"Jellyfish lack basic sensory organs and a brain, but their nervous systems and rhopalia allow them to perceive stimuli, such as light and odour, and respond quickly."
and
"Some jellyfish also have ocelli: light-sensitive organs that do not form images but are used to determine up from down, responding to sunlight shining on the water's surface."
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Originally posted by twhiteheadSomeone here brought that the eye more than likely started due to
Kelly,
Do you accept my following claims:
1. Many cells are light sensitive for reasons other than sight. Eg most plant cells (produce energy), human skin cells (manufacture vitamin D).
2. Most organisms have some form of transmiting messages from one part of thier body to another. Most animals do so rapidly (a consequence of a mobile lifestyle). Such are used to determine up from down, responding to sunlight shining on the water's surface."
a light sensitive patch that appeared and that was why it was the
point of discussion. They also stated they would debate the
evolution of the eye if I disagreed with that, and they either couldn't
come up with valid reason, or didn't want to actually defend that
belief. Since then they claimed because of some of my religious
beliefs they no longer wanted to debate the issue.
1. Many cells are light sensitive for reasons other than sight. Eg most plant cells (produce energy), human skin cells (manufacture vitamin D).
Sure, I accept this.
2. Most organisms have some form of transmiting messages from one part of thier body to another. Most animals do so rapidly (a consequence of a mobile lifestyle). Such a mechanism is not dependent on sight.
Yep, even cells are complicated creatures.
“If you do, then why do you claim that more than one new feature is required for sight aquisition?”
The skin on my butt can react to light, that doesn’t mean eyes are
going to form there. Changing the way the system handles
information is as complicated as all points I brought up earlier. Is that
what you think occurred, it took a system already in place and made it
do something else later?
Kelly
Originally posted by KellyJayEvolution seems to often work exactly this way - that is, take something that already exists and adopt it to another purpose.
Someone here brought that the eye more than likely started due to
a light sensitive patch that appeared and that was why it was the
point of discussion. They also stated they would debate the
evolution of the eye if I disagreed with that, and they either couldn't
come up with valid reason, or didn't want to actually defend that
belief. Since then they ...[text shortened]... think occurred, it took a system already in place and made it
do something else later?
Kelly
Our ear bones match similar structures in the gills of fish and it may well be that these structures were adapted from one purpose - extracting dissolved oxygen from water - to another - hearing.
I don't see why the same couldn't happen for light sensitive cells.
Granted, the eye is just a little bit more complex than a light sensitive cell - but the whole thing doesn't have to happen at once, and we do have a lot of time available (assuming you accept the age of the earth!)
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Originally posted by amannionNo! Just because most people can survive without an appendix does not mean it does nothing.
I don't see your point. The appendix must be useful because at can get infected. How does that make any sense?
The fact is appendixes do nothing.
Like any other part of our body, they can become infected and this is a problem which necessitates their removal.
In fact if having an appendix is, overall, a liability, it would gradually die out.
What we do know is that we don't know everything, yet. 😉
edit: eg http://en.wikipedia.org/wiki/Vermiform_appendix
Originally posted by KellyJayPoor analogy. The human body and the way it works is nothing like a computer.
The issue isn't resolved by items being internal or external, the point
to the whole thing was when you get a new device, if the system is not
setup for it, it will not work. There are plenty of computer parts that
can be either internal or external and both require drives and the
proper wiring.
I'm not debating if light sensitive cells exist or not, ...[text shortened]... about evolution that cannot be backed up, but must be
accepted as truth nonetheless.
Kelly
Did you think the body comes ready with a usb port, when an eye came along it slots in fully working?
Perhaps the problem here is you are still thinking in terms of Usher's timescales for everything to happen, rather than countless generations. Remember the eye did not evolve on humans, rather in the long and distant past. I'm sure there are studies looking at different eyes and how similar ours are to other mammals, just find em and read. How many mammals have two eyes? why don't some have three (like Blinky!) or eight like some spiders, etc etc.
The likelihood is that eyes only developed once, and binocular vision being the most efficient with resources, became the dominant feature set amoungst all life (that's how long ago it happened!)...
Originally posted by KellyJaySomeone! Not someone KJ, it was me.
Someone here brought that the eye more than likely started due to
a light sensitive patch that appeared and that was why it was the
point of discussion. They also stated they would debate the
evolution of the eye if I disagreed with that, and they either couldn't
come up with valid reason, or didn't want to actually defend that
belief. Since then they ...[text shortened]... think occurred, it took a system already in place and made it
do something else later?
Kelly
I told you earlier that everybody can find a huge database full of info regarding this matter and in adition I replied to all your questions -but in vain. I understand you prefer to stick on your beliefs, well it's fine with me. But you cannot claim that I did not respond in our conversation.
The truth is that you refuse the scientific finds and evidence because you deny science in the name of your "good book". It is only just a click away, but no bother, I will do it for you -the simpler answers can be found at http://www.talkorigins.org/indexcc/CB/CB301.html
So:
BOX
Claim CB301:
The eye is too complex to have evolved.
Source:
Brown, Walt, 1995. In the Beginning: Compelling evidence for creation and the Flood. Phoenix, AZ: Center for Scientific Creation, p. 7.
Hitching, Francis, 1982. The Neck of the Giraffe, New York: Meridian, pp. 66-68.
Response:
This is the quintessential example of the argument from incredulity. The source making the claim usually quotes Darwin saying that the evolution of the eye seems "absurd in the highest degree". However, Darwin follows that statement with a three-and-a-half-page proposal of intermediate stages through which eyes might have evolved via gradual steps (Darwin 1872).
photosensitive cell
aggregates of pigment cells without a nerve
an optic nerve surrounded by pigment cells and covered by translucent skin
pigment cells forming a small depression
pigment cells forming a deeper depression
the skin over the depression taking a lens shape
muscles allowing the lens to adjust
All of these steps are known to be viable because all exist in animals living today. The increments between these steps are slight and may be broken down into even smaller increments. Natural selection should, under many circumstances, favor the increments. Since eyes do not fossilize well, we do not know that the development of the eye followed exactly that path, but we certainly cannot claim that no path exists.
Evidence for one step in the evolution of the vertebrate eye comes from comparative anatomy and genetics. The vertebrate βγ-crystallin genes, which code for several proteins crucial for the lens, are very similar to the Ciona βγ-crystallin gene. Ciona is an urochordate, a distant relative of vertebrates. Ciona's single βγ-crystallin gene is expressed in its otolith, a pigmented sister cell of the light-sensing ocellus. The origin of the lens appears to be based on co-optation of previously existing elements in a lensless system.
Nilsson and Pelger (1994) calculated that if each step were a 1 percent change, the evolution of the eye would take 1,829 steps, which could happen in 364,000 generations.
Links:
Lindsay, Don, 1998. How long would the fish eye take to evolve? http://www.don-lindsay-archive.org/creation/eye_time.html
References:
Darwin, C., 1872. The Origin of Species, 1st Edition. Senate, London, chpt. 6, http://www.talkorigins.org/faqs/origin/chapter6.html
Nilsson, D.-E. and S. Pelger, 1994. A pessimistic estimate of the time required for an eye to evolve. Proceedings of the Royal Society of London, Biological Sciences, 256: 53-58.
Shimeld, Sebastian M. et al. 2005. Urochordate βγ-crystallin and the evolutionary origin of the vertebrate eye lens. Current Biology 15: 1684-1689.
Further Reading:
Dawkins, Richard, 1996. Climbing Mount Improbable, New York: W.W. Norton, chpt. 5.
Land, M. F. and D.-E. Nilsson, 2002. Animal Eyes. Oxford University Press.
Fernald, Russell D. 2006. Casting a genetic light on the evolution of eyes. Science 313: 1914-1918.
BOX-OFF
That's all, KJ;
Originally posted by snowinscotlandWhy would it die out?
No! Just because most people can survive without an appendix does not mean it does nothing.
In fact if having an appendix is, overall, a liability, it would gradually die out.
What we do know is that we don't know everything, yet. 😉
edit: eg http://en.wikipedia.org/wiki/Vermiform_appendix
If it has no effect on the body - positive or negative - there is no pressure on the body to do anything.
Thanks for the wikipedia reference but I'm not a big fan of truth developed by the masses.
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Originally posted by amannionI fail to see why you just accept this as something that just happened?
Evolution seems to often work exactly this way - that is, take something that already exists and adopt it to another purpose.
Our ear bones match similar structures in the gills of fish and it may well be that these structures were adapted from one purpose - extracting dissolved oxygen from water - to another - hearing.
I don't see why the same couldn't h n at once, and we do have a lot of time available (assuming you accept the age of the earth!)
You are just buying into this is just how evolution must have done it,
is right up there with people who say God did it. Let me give you my
reasons why I think this before you get insulted.
One of the major complaints against those of us who believe in
creation is that we just buy into "a story" and nothing beyond that
is going to sink in and change our minds about the past. Why is
it that you assume evolution must be given credit for the eye, why
are you defending it here when there is nothing here to defend?
"Evolution seems to often work exactly this way - that is, take
something that already exists and adopt it to another purpose."
You really do not have anything to hang your hat on, yet even if you
do not have specifics you have a belief that evolution did it, you just
do not seem to know how yet. How is that different than someone saying
God did it, and they just don't know how yet? The locked in thought
in this is, that evolution must be given credit for the eye, even if we
cannot come up with any real reason for that, just a bunch of maybe
this occurred this way or that? Saying that evolution does have the
ability to take something that exists and adopt it to another purpose
does not address the point of the eye at all, since evolution would
have had to setup the whole process from beginning to end. If it
can only deal with existing life, than I’ll buy into the story, but that
opens the door into creation which most good evolutionist reject out
of hand.
I do not think you have really given me anything yet to work with,
by suggesting some cells could be or would have been light sensitive.
Being light sensitive does not suggest sight, it could suggest some
form of damage when it gets exposed to light, or some form of
something else, but all of that is still a far cry from the eye.
Kelly
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Originally posted by snowinscotlandYour countless generations do not add strength to your position it
Poor analogy. The human body and the way it works is nothing like a computer.
Did you think the body comes ready with a usb port, when an eye came along it slots in fully working?
Perhaps the problem here is you are still thinking in terms of Usher's timescales for everything to happen, rather than countless generations. Remember the eye did not ces, became the dominant feature set amoungst all life (that's how long ago it happened!)...
weakens it! In complex systems with life you'd have to have several
different things, like the various parts of the eye forming not only
separately but independently as well, so things like the connections
to brain could be forming without maybe even a brain there to
connect too, the way blood flowed through the eye without maybe
a heart, eye lids without eyes, and a large variety of other odds and
ends appearing with no central builder or designer just getting all
the right proportions correct, all the proper tolerances correct, and
while they were forming through countless generations they were
doing nothing but drawing resources from the life form in question
and it getting nothing in return since the reason for these parts had
yet to be realized, this would have to put any creature’s existence
in complete jeopardy due to it's depleted resources, and this would remain
true until the eye is formed, you’d have a bunch of extra useless parts.
Kelly
Originally posted by black beetleRespond to someone else please, we are done with each other
Someone! Not someone KJ, it was me.
I told you earlier that everybody can find a huge database full of info regarding this matter and in adition I replied to all your questions -but in vain. I understand you prefer to stick on your beliefs, well it's fine with me. But you cannot claim that I did not respond in our conversation.
The truth is that yo ...[text shortened]... netic light on the evolution of eyes. Science 313: 1914-1918.
BOX-OFF
That's all, KJ;
remember, you called it, please honor that.
Kelly
Originally posted by KellyJayNo, this is wrong.
Your countless generations do not add strength to your position it
weakens it! In complex systems with life you'd have to have several
different things, like the various parts of the eye forming not only
separately but independently as well, so things like the connections
to brain could be forming without maybe even a brain there to
connect too, the wa ...[text shortened]... would remain
true until the eye is formed, you’d have a bunch of extra useless parts.
Kelly
It assumes that only a proper working eye is useful to the creature that has one and that anything short of that is useless.
There are many examples of living creatures that make do with eyes or similar organs that are only partially working by our standards.
Originally posted by KellyJayIt's entirely different.
I fail to see why you just accept this as something that just happened?
You are just buying into this is just how evolution must have done it,
is right up there with people who say God did it. Let me give you my
reasons why I think this before you get insulted.
One of the major complaints against those of us who believe in
creation is that we just bu ...[text shortened]... t, or some form of
something else, but all of that is still a far cry from the eye.
Kelly
Saying god did it ends any argument or discussion.
Saying evolution did it simply starts the discussion as yours and my posts indicate.
I don't know the steps involved, nor am I sure that anyone does. And yes, I place my faith in evolution as a process that will give us the answer to this and other questions of the development of life. But it's an entirely different faith to a faith in god.
Originally posted by KellyJayKJ - your statement regarding "just a bunch of maybe" with regards to your opinion on the evolution of the eye is completely unsubstantiated. If you want the truth have a serious read of the literature before you make wild statements like this. You get more pathetic each day with your tiresome and obtuse posts.
I fail to see why you just accept this as something that just happened?
You are just buying into this is just how evolution must have done it,
is right up there with people who say God did it. Let me give you my
reasons why I think this before you get insulted.
One of the major complaints against those of us who believe in
creation is that we just bu ...[text shortened]... t, or some form of
something else, but all of that is still a far cry from the eye.
Kelly
If you truely want to learn about the evolution of the eye, the articles the last poster pointed to (amongst many many others) are available to you. You honestly don't need someone to hold your hand to gain this knowledge....... which we all know you truely don't want.
If you have questions specifically regarding a paper on the subject which you believe to be false, then lets do that. It will certainly be more constructive than your continual obtuse manner.
Originally posted by amannionYou are correct and what you describe is called an exaptation.
No, this is wrong.
It assumes that only a proper working eye is useful to the creature that has one and that anything short of that is useless.
There are many examples of living creatures that make do with eyes or similar organs that are only partially working by our standards.