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What is evolution?

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posted on May, 28 2010 @ 11:22 PM
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reply to post by stereologist
 


It's necessary for us scientifically literate individuals to tear down misinformation and misunderstanding. If everyone understood that evolution was fact, we would even need this particular forum on the discussion board.




posted on May, 29 2010 @ 12:21 AM
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reply to post by PieKeeper
 


Very true. It is important for people to realize that scientific thinking allows for mistakes to be made and corrected.

I think that the non-scientific ideas like creationism have the idea that all people in science think the same is true. Not at all. I read all of the posts to see what I can learn. I may know things and not be able to describe them well. I may think I know things and learn more about them and change my position based on better or more recent information supplied. I may make a statement and get corrected by someone. I expect to learn.

I hope that others keep an open mind and learn as well.



posted on May, 29 2010 @ 03:15 AM
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reply to post by txpiper
 





That’s nonsense. There is no perception of surroundings at all unless the whole system is functional. If what you say is true, you should be able to note endless examples of worthless biological features that appear to be on their way to becoming useful. What would you use as an example?




Some blind people are capable of distinguishing between light and dark from their skin. Light sensitive cells are pretty common. An organism that can distinguish between light and dark has a valuable advantage over a creature that cannot.

Light sensitive cells are absolutely gaining a perception of their surroundings. Of course it is not as good as more fully developed eyes, but it is not a "worthless biological feature".

No biologic feature is worthless or it would not survive natural selection for long. But a valuable biologic feature can be improved upon or it may take on other functions as its original function is superseded by other strategies.

[edit on 29/5/2010 by rnaa]



posted on May, 29 2010 @ 10:42 AM
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reply to post by stereologist
 



I think that the non-scientific ideas like creationism have the idea that all people in science think the same is true. Not at all.

Of course they don’t. Bacon, Kepler, Boyle, Pascal, Newton, Linneaus, Herschel, Faraday, Morse, Mendel, Pasteur, Kelvin, Lister and many others were creationists. Lots of heavily-credentialed people are now. It is the materialists who would have everyone believe that the scientific community is monolithic in its enthusiasm for their views.



posted on May, 29 2010 @ 10:51 AM
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reply to post by rnaa
 




Some blind people are capable of distinguishing between light and dark from their skin.

That is about radiant heat, not light. It is a totally different input. The sight centers in the brain are not wired to the skin.


No biologic feature is worthless or it would not survive natural selection for long.

Exactly. That’s why there is no reason to think that eyes did or could develop from a light sensitive spot. It would be no more of an advantage that a wart. The supposed “slight advantage” is like “beneficial mutation”. Both are hyped concepts that don’t hold up under serious scrutiny.



posted on May, 29 2010 @ 12:09 PM
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reply to post by txpiper
 



Of course they don’t.

I can see right here on this thread that people see science as a group think. I have seen that sentiment in other threads in these forums. I have heard that statement made by possibly all creationist lecturers I have heard speak. Not sure if it was 100%, though I am unable to think of an exception at the moment.

There are creationists in the biological sciences. I have met them. They do research into how things work rather than origins.



posted on May, 29 2010 @ 12:19 PM
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reply to post by txpiper
 



Exactly. That’s why there is no reason to think that eyes did or could develop from a light sensitive spot. It would be no more of an advantage that a wart. The supposed “slight advantage” is like “beneficial mutation”. Both are hyped concepts that don’t hold up under serious scrutiny.


Very bad thinking on your part. A light sensitive spot provides a notion of orientation. A sense of radiant heat is just a "light spot" sensing a nearby part of the spectrum.

Anything that makes it possible to detect the presence of predators is an advantage. A light detector can be a means of navigating to shadows. A light detector can mean vertical navigation to a place in the water column that is dim light during daylight hours. A clump of detectors may allow an organism to detect where a shadowed area is without having to stumble onto it using a drunkards walk.

To claim that there is no more advantage than offered by a wart is sign this wasn't thought out. I haven't even cracked a book or a link to consider the possibilities.

I think that anyone that does not understand that mutations can be harmful, beneficial, or indifferent does not wish to understand the working of nature. It sounds to me like a hide the head in the sand effort.



posted on May, 29 2010 @ 11:44 PM
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reply to post by stereologist
 



Anything that makes it possible to detect the presence of predators is an advantage.

The problem is that what would amount to nothing more than a lesion or blemish does not detect light so that it registers as an image in the brain.

I didn’t get an answer when I asked another poster, but maybe you can respond. If things like eyes, ears, kidneys, teeth, tentacles, feathers and everything else were produced by mutations/selection, then they all at one time were in a lesser stage than they are now. There are hundreds of thousands, perhaps millions of species now living. There should be countless features that are still not quite all they can be. Can you list a few that you think would be good examples?


I think that anyone that does not understand that mutations can be harmful, beneficial, or indifferent does not wish to understand the working of nature.

Well, if they are really the mechanism that makes organisms more sophisticated, why is the list of beneficial ones so impoverished? Why does it always include sappy things like the sickle cell anemia/resistance to malaria? Why doesn’t it include mutations that are obviously altering a bio-structure or producing a novel specialization?

And while you are at it, why do you think cave species lose their eyes and pigment?



posted on May, 30 2010 @ 12:17 AM
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Can you list a few that you think would be good examples?

Sure. I'm not trying to funny or cute here.

Eyes, ears, kidneys, teeth, tentacles, feathers, and all things that could be better. Our eyes do not see UV, but insects and spiders can. What about the eyes of the horseshoe crab. Now those are eyes. They can see from moonless nights to bright daylight. Our ears do not hear as well as the ears of a dog. And so forth.

Take a look at the range of light sensing organs in life today. The range is amazing. You think these are all the same or do you think that Some "are still not quite all they can be."


Well, if they are really the mechanism that makes organisms more sophisticated, why is the list of beneficial ones so impoverished? Why does it always include sappy things like the sickle cell anemia/resistance to malaria? Why doesn’t it include mutations that are obviously altering a bio-structure or producing a novel specialization?

There is no goal to evolution. There is no goal to make more sophisticated organisms. That's a goal. One older evolutionary theory is Lamarkism. It was goal oriented.

The development of the neocortex is an example of a structure that led to language for instance.


And while you are at it, why do you think cave species lose their eyes and pigment?

Interesting question. At least some of the species I am aware of get their pigment back when exposed to light. The lack of pigment appears to be a response to lack of light, at least in some species.



posted on May, 30 2010 @ 01:10 PM
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reply to post by stereologist
 



Sure. I'm not trying to funny or cute here.

Eyes, ears, kidneys, teeth, tentacles, feathers, and all things that could be better….

ha ha…I left myself open for that. Let me rephrase my question.

Every bio-feature, at some stage in its development, had to be non-functioning before everything involved in it was integrated. Even with fully “evolved” eye components, if there were no optic nerves, or no holes in the skull for them to pass through, or no sight management centers in the brain, sight would not be occurring. There had to come a point, where one really dandy germ-line mutation occurred that threw the switch for light perception.

So, what would be an example of an incomplete system?


There is no goal to evolution. There is no goal to make more sophisticated organisms. That's a goal.

Yes, that is the standard response. But it is hard to imagine that a random, meandering, undirected process would result in so many things that are definitely goal-oriented. Like antibodies, or a jillion other things that do what they are supposed do. Or like all the enzymes who mount a coordinated, interdependent effort during DNA replication. Processes like that are discriminating. How would you characterize their performance without using the word “intelligence”? How would you suppose that such enzymes were originally formed?


Interesting question. At least some of the species I am aware of get their pigment back when exposed to light. The lack of pigment appears to be a response to lack of light, at least in some species.

But why do they lose their eyes? Is this not an obviously Lamarckian response?

The reason I am interested in your appraisal is that they lose their eyes because there is no light perception. If useless functions are discarded, why would eyes continue to evolve until they are functional?



posted on May, 30 2010 @ 02:58 PM
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Originally posted by txpiper
So, what would be an example of an incomplete system?

At the moment our limbs are incomplete wings. Should selective pressure push us towards aviation our limbs could easily turn into wings in some millions of years.



Yes, that is the standard response. But it is hard to imagine that a random, meandering, undirected process would result in so many things that are definitely goal-oriented.

Since there is selective pressure the process can't be called random and undirected.



But why do they lose their eyes? Is this not an obviously Lamarckian response?

Ultimately making eyes results as decreased reproductive output if eyes serve no function in given environment. Thus selective pressure pushes towards less resource loss towards making eyes. It's not a Lamarckian response, however it's a Darwinian one.



posted on May, 30 2010 @ 04:15 PM
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reply to post by txpiper
 


Remember that what we see for a visual system today is not the visual system that suddenly popped into existence. There isn't a point in time in which a mutation connects a bunch of unrelated components that become a visual system.

Looking for an incomplete system is something that does not exist. We look at animals today and see some functionality in what we see.

Let's go back to the light sensor. What do we know about light. It's at a frequency where the incoming photons can trigger chemical reactions that involve electrons in the outer shells. Less energetic photons are not good at causing reactions and more energetic photons can cause reactions that are hard to undo. So seeing and photosynthesis utilize EM in a range where chemical reactions are reasonable to handle, so to speak. A light senstive cell is in effect an incomplete system because it is not hooked up to all of the fancy gadgetry you mentioned. On the other hand it is not a useless and so-called incomplete system.

I suggest that your search for an incomplete system is really a search for something that does not exist. It's a misdirection.


Yes, that is the standard response. But it is hard to imagine that a random, meandering, undirected process would result in so many things that are definitely goal-oriented. Like antibodies, or a jillion other things that do what they are supposed do. Or like all the enzymes who mount a coordinated, interdependent effort during DNA replication. Processes like that are discriminating. How would you characterize their performance without using the word “intelligence”? How would you suppose that such enzymes were originally formed?

This is the standard response as well. Evolution is not random. It is not goal oriented. It is survival oriented. The underlying mechanism is random, but on top of that is the need to survive. So if antibodies and the "jillion other things" increase survival, then they are likely to persist. Why would I characterize a system as intelligent if it has the inherent flaw of autoimmune diseases. Do you think autoimmune diseases are based on intelligence? Do how did the chemicals for self replication arise? That exists in the study of the origin of life, not in evolution.


But why do they lose their eyes? Is this not an obviously Lamarckian response?

Ever broken a limb or know someone that did? Ever seen how atrophied the limb is from lack of use? Ever exercise to bulk up? Ever wonder why the body adjusts itself to suit the effort it is making?

Why doesn't the body build up with huge bones and muscles that allow a person to carry huge loads? Why do we have to exercise to be strong?

The beauty of life is that living organisms can to some degree adjust to their environment. Bones are only as heavy and strong as they need to be. Muscles do not grow without regard to available food supplies. Neurons are notorious energy and oxygen demanding cells. In a nutrient restricted environment such as a cave it is possible that fish have enhanced survival if they drop part of their systems. Less demands means greater survival. In the world of light loss of eyes means being easy prey. Drop that issue and loss of eyes may increase survival. I do not have scientific evidence for this.


If useless functions are discarded, why would eyes continue to evolve until they are functional?

The eyes are not "discarded". The eyes are no longer needed for survival. Their loss is due to the gain in reducing nutrient requirements.



posted on May, 30 2010 @ 07:46 PM
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reply to post by rhinoceros
 



At the moment our limbs are incomplete wings. Should selective pressure push us towards aviation our limbs could easily turn into wings in some millions of years. Since there is selective pressure the process can't be called random and undirected.

I don’t think any thinking fairy would encourage that. How would you eat chili dogs?



posted on May, 30 2010 @ 08:00 PM
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reply to post by stereologist
 



There isn't a point in time in which a mutation connects a bunch of unrelated components that become a visual system.

Well, how would it all come together? Do you think the optic nerve “evolved” independently, unrelated to the eye? Did the interpretive center in the brain do the same? Did the ten layers of the retina form independently, or in unison? Can you outline the series of mutations that would be involved in doing all this?


The beauty of life is that living organisms can to some degree adjust to their environment.

Well yes, and that’s easy to appreciate. But I want to understand how DNA replication errors built that flexibility. It is very difficult to get straight answers to questions about this idea. It should not be because change by way of mutations is the bedrock of evolutionary theory. It surprises me how people trust the premise don’t ever want to explore it.



posted on May, 30 2010 @ 09:54 PM
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reply to post by txpiper
 



Well, how would it all come together? Do you think the optic nerve “evolved” independently, unrelated to the eye? Did the interpretive center in the brain do the same? Did the ten layers of the retina form independently, or in unison? Can you outline the series of mutations that would be involved in doing all this?

The simplest form would have the 'eye' at the neural center. A separation of the eye from the 'brains' of the creature is seen in most animals, for example arthropods, chordates, and mollusks.

I would agree with you that it would be outlandish to assume that an eye, a visual center in the brain, and the 'cabling' to evolve separately. It is more reasonable that these were tightly connected and it was advantageous to separate the eye from the brain. Having the brain at the surface of an animal seems like asking for trouble.

I did explore the issue by suggesting the following:

Their loss is due to the gain in reducing nutrient requirements.


In some creatures the loss of pigment is reversed by exposure to light. In other cases, the loss is permanent. In one case there is no mutation. In the other case there is. Cave creatures exhibit both cases.

My guess or opinion on the benefit of being blind needs some more backing I can see. So I broke down and did a little research.
Science: Making Blind (Cave Fish) See Again

Eventually these fishes lost their ability to grow eyes at all because the lack of sight presented no detriment to survival and in fact, because eyes are energetically expensive structures to make, there was selective pressure against their development and maintenance.

OK, so someone else out there is thinking along the lines I guessed.


Why is this so interesting, since all the populations are blind? This is important because some hybrids between different populations have had their sight restored in just one generation, according to a study that was just published.


Original article
Restoring sight in blind cavefish

Twenty-nine populations of the blind cavefish, Astyanax mexicanus, are known from different caves in North-Eastern Mexico (Figure 1). They evolved from eyed, surface-dwelling forms which only reached the area in the mid-Pleistocene. Quantitative genetic analyses have shown that the evolutionary impairment of eye development — as well as the loss of pigmentation and other cave-related changes — results from mutations at multiple gene sites (‘eye loci’). Eye loss has evolved independently at least three times and at least some of the eye loci involved differ between the different cave populations. Hybrids between blind cavefish from different caves have larger and better developed eye rudiments than their parents (Figure 2), reflecting these independent origins and complementation. Given the large number of mutations at different loci that have accumulated in these populations, we reasoned that hybridization among independently evolved populations might restore visual function. Here we demonstrate restoration of vision in cavefish whose immediate ancestors were blind and whose separate lineages may not have been exposed to light for the last one million years.


During my quick research I did bump into this article.
New eyes for blind cave fish?
This is a creationists blog entry on an experiment with blind cave fish, not the same experiment. He claims and I say quite falsely that this is an example of a "downhill slide." The claim of many creationists is that mutations are always bad, never good. Things can only be worse. You can't add new genes.

The claim is false. New genes can be added. New genes have been induced in experiments and observed. In the case of the blind cave fish the author of the blog does not address the energy issue of eyes. It is assumed that the eye is blinded because of injury possibilities.

Finally, comments at the end of this blog entry discuss other benefits due to gene changes in blind cave fish.
Cave Fish and Selection?



posted on May, 30 2010 @ 10:29 PM
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reply to post by txpiper
 




So, what would be an example of an incomplete system?...


You continue to miss the point. An "incomplete system" would imply there is such a thing as a "complete system" to move towards and that would be a goal. Evolution is survival oriented, not goal oriented. Or if you prefer, the only goal is survival of the population (not the individual).

No biological system is in an incomplete state of evolution; every biological system is fully evolved in whatever state it is in; there is no goal system. A subsequent mutation to that system that provides reproductive advantages to the organism will come to dominate the population. That does not make one 'state' less or more 'evolved' than the other, it makes it more successful in the current environment, the population survives 'better'.

If you want to see examples of animals that demonstrate the various stages of evolution that the human eye has passed through to get to where it is now, there are many such descriptions on the web. It doesn't take much effort to google "eye evolution". Here are a few that come up on top of the list:



A Richard Attenbourough video goes through it here:


And this video from the PBS doco on Darwin is great (It gets especially and specifically pertinent at about the 5:50 mark):




If useless functions are discarded, why would eyes continue to evolve until they are functional?


Again, just for emphasis:

They are never useless at any stage of their evolution; they are fully functional for what they are. Not every eye is as good as the modern human eye, but then again some are better in certain respects.

Every eye is a complete eye and provides a useful a function improving reproductive advantage over what ever "eye" condition preceded them.

Discarding a function that is no longer needed is saving on resources. With the eyes gone, the visual processing centers in the brain can be re-purposed to handling echo sounding or electric field sensing or whatever. In other words, 'visible' spectrum sensing is not the only way to 'see'.


[edit on 30/5/2010 by rnaa]



posted on May, 31 2010 @ 10:02 AM
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Well, I’m not able to communicate the issue. I’ll just summarize the problem once more and let this go.

Mutations simply cannot produce the fantasy enhancements that are attributed to them in all the rosy, hyper-optimistic, step-by-step, developmental scenarios. Evolutionary change is 100% dependant on random DNA replication errors. There are monumental complications and obstacles which make this a ridiculous idea.



posted on May, 31 2010 @ 12:27 PM
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I have very clearly understood your claim. The problem is that you seem unwilling to take the time to understand or review the material that is being presented. When you label something as having "monumental complications", I can see that you still do not want to consider that simple things turned into more complicated things over time. It is hard to get past a young Earth position where no time is allotted for change. Maybe at some point in the future you can take the time to sit down and work through a sequence of evolutionary changes and come up with some tough real questions. It's a lot better than doing the screaming denial act you did in your previous post.



posted on May, 31 2010 @ 09:14 PM
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reply to post by stereologist
 



…you still do not want to consider that simple things turned into more complicated things over time.

Well first, the time available is not unlimited. You can often use supposed dates and lineages to determine the constraints for development of novel features such as whale echolocation or elephant trunks.

But to me, your statement indicates gross oversimplification. A mutation that results in a novel functioning protein is anything but simple. Alterations or substitutions in some protein sequences may be tolerated to a very limited degree, but this is not the usual expectation. The results are most often undesirable, ranging from dysfunctional to deadly.

Honestly, I think the whole idea of mutations being a reliable source of enhanced genetic information is just something evolutionary theorists are stuck with. There just isn’t anything else ideologically pleasing available. That's why the emphasis is always shifted to selection.







[edit on 31-5-2010 by txpiper]



posted on May, 31 2010 @ 09:32 PM
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Originally posted by txpiper
The results are most often undesirable, ranging from dysfunctional to deadly.


Common misconception. Most mutations don't do anything.



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