Originally posted by amannionThe appendix must serve several functions, albeit that we do not understand what they are, particularly as there are cases of death through infection. A harmful mutation would tend to disappear fairly quickly, so there must be a balance with the appendix serving a positive function at some stage.
I would think that light sensitive cells - the first eyes if you like - would be like any other mutation.
For those creatures that first developed these cells they may well have been irrelevant and useless. A useless feature will be kept of course if it does no harm - think of the appendix for most people. But useless features can gradually develop to beco ...[text shortened]... case, since light sensitive cells now dominate in yours and my eyes and in many other creatures.
The other point about 'useless' organs is that in all probability they will tend to change through time (perhaps even disappear). We must not forget however that the entire population changes every generation, so we are constantly in a state of flux. 'Modern' human is only modern for one generation.
Originally posted by KellyJayYes I see what you're saying (ha ha!) but I think you may have missed my point. You're right in the notion of trying and needs as mistaken terms, but what I'm saying is that once an organism has a feature - say light sensitive cells - there's no reason why that feature can't be used for other purposes.
"Needs" also do not come into play with evolution, that is a design
term. There isn't any "try", there isn't any "needs to", there isn't any
"try outs" it does seem to me when people speak about evolution they
do tend to use design terms when describing it, yet they will at the
same time argue strongly that design isn't part of the process. So the
chan ...[text shortened]... ot know if you
see why I'm still wondering why the eye could have happened?
Kelly
It may serve no use at all to an organism initially, but the organism takes advantage of this feature at a later stage.
Originally posted by KellyJayNot sure about light input confusing an organism since the earliest organisms with light sensitive cells would not have had brains nor nervous systems and so could not be confused.
I have a hard time with terms like "tried out" when speaking of
evolution, it isn't like evolution looks at things to see if they work or
not and goes on the next thing. If an evolutionary path is taken and
it leads to a dead end it will get to a dead end, there isn't a do over.
The thing about life is once the process stops, that is it, it isn't a vide ...[text shortened]... ve given that life an advantage"
as if just saying that some how makes it so.
Kelly
As for evolutionary dead ends - I'm talking about features of organisms not entire organisms. A dead end feature does not mean that the creature dies. It simply means that feature is not useful to the creature.
Originally posted by snowinscotlandI don't see your point. The appendix must be useful because at can get infected. How does that make any sense?
The appendix must serve several functions, albeit that we do not understand what they are, particularly as there are cases of death through infection. A harmful mutation would tend to disappear fairly quickly, so there must be a balance with the appendix serving a positive function at some stage.
The other point about 'useless' organs is that in al ...[text shortened]... , so we are constantly in a state of flux. 'Modern' human is only modern for one generation.
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.
Originally posted by amannionI disagree about not having a useful purposes too, with each new
Yes I see what you're saying (ha ha!) but I think you may have missed my point. You're right in the notion of trying and needs as mistaken terms, but what I'm saying is that once an organism has a feature - say light sensitive cells - there's no reason why that feature can't be used for other purposes.
It may serve no use at all to an organism initially, but the organism takes advantage of this feature at a later stage.
feature in order to keep that intact it will draw resources from the
rest of the living system which typically is a very balanced
system. Someone else said years ago that doing that would be
like putting in new gears inside of a clock that do nothing but
add to the over all amount of work the clock must do. So at best
what you get is like some form of leach which draws vital
energy from the rest of the system in order to support a new
piece of the puzzle that currently does not have a use at the
moment. That to me would place that life form that acquired the
new piece of whatever, at a distinct disadvantage having to use
up more energy supporting itself and not having anything but a
drain on system resources to show for it.
Kelly
Originally posted by amannionWould you address notion that some how a never before seen new
Yes I see what you're saying (ha ha!) but I think you may have missed my point. You're right in the notion of trying and needs as mistaken terms, but what I'm saying is that once an organism has a feature - say light sensitive cells - there's no reason why that feature can't be used for other purposes.
It may serve no use at all to an organism initially, but the organism takes advantage of this feature at a later stage.
light sensitive spot on a life form could some how be an advantage
and not a disadvantage? I do not see how such a thing would be
anything but a drain on a system without adding to it at all one way
or another. Could you tell me why it would not be like giving a
blind man a telescope and saying he has an advantage to all the
other blind men in the area.
Kelly
Originally posted by KellyJayBut the appendix is a classic example of just such a useless object. With or without it makes absolutely no difference to the functioning o a human body.
I disagree about not having a useful purposes too, with each new
feature in order to keep that intact it will draw resources from the
rest of the living system which typically is a very balanced
system. Someone else said years ago that doing that would be
like putting in new gears inside of a clock that do nothing but
add to the over all amount of work ...[text shortened]... upporting itself and not having anything but a
drain on system resources to show for it.
Kelly
Originally posted by amannionThat is all fine and good, for a large multi-cell creature, but what
But the appendix is a classic example of just such a useless object. With or without it makes absolutely no difference to the functioning o a human body.
of the one that is only one cell or just a few where the loss of
resources in small degrees could mean something vital may not
be done correctly or at all? When did the light patch appear
according to modern thought?
Kelly
Originally posted by KellyJayClearly the blind man analogy is false since it relies on an ability to see. To a bunch of 'sightless' micro-organisms there may be no initial advantage to light sensitive cells. They go about the business of extracting resources from their environment as they have before.
Would you address notion that some how a never before seen new
light sensitive spot on a life form could some how be an advantage
and not a disadvantage? I do not see how such a thing would be
anything but a drain on a system without adding to it at all one way
or another. Could you tell me why it would not be like giving a
blind man a telescope and saying he has an advantage to all the
other blind men in the area.
Kelly
But those light sensitive cells may allow an organism that has them to better orient themselves to take advantage of the resource extraction - ie. eating - that keeps them alive. But they could do that anyway you say, why do the light sensitive cells help? Well of course they could do that, but it may be that with the light sensitive cells they can do it better. Any advantage, however slight, will be seized upon by natural selection - this individual will out compete others and be more likely to successfully reproduce.
Of course, all of this is contingent upon the light sensitive cells not being burdensome as you quite rightly note.
My response is I guess a little glib and may be seen as a cop out, but may also be as good as we can expect at the moment - the fact that we have light sensitive cells suggest that it wasn't a burden on the creatures that evolved them.
I should also point out that evolutionary studies suggest that such light sensitive cells have independently evolved more than once. That suggests that there is some advantage to having them.
Originally posted by KellyJayI have no idea, and of course palaeontology makes dating of the origin of cellular material pretty difficult. I take your point, but I would imagine the development occurring only in a multi-cellular organism. Even a bacterium has many cells and quite significant complexity ...
That is all fine and good, for a large multi-cell creature, but what
of the one that is only one cell or just a few where the loss of
resources in small degrees could mean something vital may not
be done correctly or at all? When did the light patch appear
according to modern thought?
Kelly
Originally posted by amannionThe blind man analogy was used because yes the blind man could
Clearly the blind man analogy is false since it relies on an ability to see. To a bunch of 'sightless' micro-organisms there may be no initial advantage to light sensitive cells. They go about the business of extracting resources from their environment as they have before.
But those light sensitive cells may allow an organism that has them to better orient ...[text shortened]... ependently evolved more than once. That suggests that there is some advantage to having them.
not see, and he was given something that can take in sights at a
distance. He could put it to his non-working eyes and get nothing,
and why would that be, BECAUSE he is blind, and nothing that
telescope could for him would change that. You are telling me a blind
piece of life gets a light sensativie spot, it is blind, and it has never
before dealt with that kind of data, so how would it process this new
information? Like the blind man it may have a nice light sensitive
spot, but what good is that if cannot process the data? If you are
telling me that it does process the data, we go back to the how do
you know such a thing would be an advantage and not a
disadvantage? Is it just accepted without reason that would be true?
Kelly
Originally posted by KellyJayClearly we don't have all of the steps or the explanations for the steps.
The blind man analogy was used because yes the blind man could
not see, and he was given something that can take in sights at a
distance. He could put it to his non-working eyes and get nothing,
and why would that be, BECAUSE he is blind, and nothing that
telescope could for him would change that. You are telling me a blind
piece of life gets a light s ...[text shortened]... advantage and not a
disadvantage? Is it just accepted without reason that would be true?
Kelly
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 of them at the moment - so there must be an advantage to having them.
Of course, I'm working under the assumption of evolution as a fact. You question that and so have a completely different criteria.
I still also question the validity of the blind man analogy. The telescope is an external feature. Light sensitive cells are internal features.
And I should add that evolution doesn't work piecemeal - a light sensitive cell here, a wing over there - mutations occur constantly and many will work in conjunction with each other,some to confer advantage and so become common, others to confer disadvantage and so be weeded out.
Originally posted by KellyJayIt is infact the data transmision and action that makes a 'light sensitive spot' sensitive. Almost all cells react internaly to light. It is only when it transmits that data to another part of the organism that it starts to take on eye like functionality.
The blind man analogy was used because yes the blind man could
not see, and he was given something that can take in sights at a
distance. He could put it to his non-working eyes and get nothing,
and why would that be, BECAUSE he is blind, and nothing that
telescope could for him would change that. You are telling me a blind
piece of life gets a light s ...[text shortened]... advantage and not a
disadvantage? Is it just accepted without reason that would be true?
Kelly
The wiring itself can also evolve seperate from light sensitivity as intracelular communication is used for many other purposes. I suspect that most single celled organisms have mechanisms to help them move towards food and away from undesirable temperatures etc. All these require an abilitiy for peripheral cells to sense and communicate to the rest of the organism. If at some point it became advantagous to move towards or away from light (which is already being sensed and even transmited to some degree) then the behavioural pattern evolves. Once the behavioural pattern evolves and the results start to benefit the organim, then the sensitivity to light starts to increase (by evolution).
Kelly Jay,
Your story with the blind man is ill considered, because if we accept the "blind man" as a species we must also accept that an exact blind creature of this specific species is disabled due to the fact that normaly his other relatives are not blind. So here we have an abnormality, which of course does not give us any room to think that the theory is false.
From your questions it is clear that you understand very well the concept of the theory of the evolution and its stable basis; in such a case you should study hard on your own and bring up scientific finds and evidence backing up your opinion, but instead you try (unsuccessfully) to deny it by hovering from "issue" to "issue". I am amazed, we even noticed you talking about those "ancient" planes!Talking with somebody with such an attitude is harder than trying to show to a 2 years old kid how to fly an F16.
I 'm a newcomer here at RHP and I joined happily this conversation with open mind and without havind a clue about your beliefs, but the coup de grace for me came when sonhouse asked you why you think that the age of the Earth is 6.000-10.000 years old: I felt quite uncomfortable.
I stop this conversation here, KJ; have a good time "debating".-
Originally posted by black beetleLater
Kelly Jay,
Your story with the blind man is ill considered, because if we accept the "blind man" as a species we must also accept that an exact blind creature of this specific species is disabled due to the fact that normaly his other relatives are not blind. So here we have an abnormality, which of course does not give us any room to think that the ...[text shortened]... te uncomfortable.
I stop this conversation here, KJ; have a good time "debating".-
Kelly