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What Birds See [evolution of the eye]
Scientific American ^ | July 2006 | Timothy H. Goldsmith

Posted on 07/03/2006 10:05:56 AM PDT by doc30

We humans customarily assume that our visual system sits atop a pinnacle of evolutionary success. It enables us to appreciate space in three dimensions, to detect objects from a distance and to move about safely. We are exquisitely able to recognize other individuals and to read their emotions from mere glimpses of their faces. In fact, we are such visual animals that we have difficulty imagining the sensory worlds of creatures whose capacities extend to other realms--a night-hunting bat, for example, that finds small insects by listening to the echoes of its own high-pitched call. Our knowledge of color vision is, quite naturally, based primarily on what humans see: researchers can easily perform experiments on cooperative human subjects to discover, say, what mixtures of colors look the same or different. Although scientists have obtained supporting information from a variety of other species by recording the firing of neurons, we remained unaware until the early 1970s that many vertebrates, mostly animals other than mammals, see colors in a part of the spectrum that is invisible to humans: the near ultraviolet. ...

(Excerpt) Read more at sciam.com ...


TOPICS: Culture/Society
KEYWORDS: bird; creationism; evolution; eye; ignoranttheocrats; kindastupid; ludditefundies; lyingforthelord; paganjunk; pavlovian; roadtohorseshitpaved; saganscience; youngearthcultists
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To: stands2reason

I think the problem here is that to some of these people can't see a difference between saying all Christians should go and all Christians that believe that Conservatives can only be Christians should go. Its the same thing to them.

They actually believe that you aren't a Conservative unless your a Christian so I told them all to go away by that neat little trick of bad logic.


181 posted on 07/03/2006 4:52:42 PM PDT by Sentis (You said the world doesn't need salvation so why do I hear it calling out for a Savior.)
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To: Capn TrVth
Amazing story. ...that beast had a made-to-order runway.

Lotta raptors of all types around these parts as well.

I know of at least one Baldy whose vision wasn't so terrific. ....perhaps he was getting old. My (110 lb) dog was out sleeping on the grass, and I was sitting about 30 ft away. Then I saw the big bird, swooping down from the trees and aiming straight for my dog. I thought "blind bird....this could get interesting." My mutt must've sensed him somehow, 'cause he lifted his head just before the Baldy got there. ....and the eagle effortlessly changed direction and continued on his way.

My dad saw one come out of nowhere to kill a rabbit about 10 feet from him. ...and then the bird just stood there with the hare in his talons and stared back at my dad for a couple minutes before making off with it.

182 posted on 07/03/2006 5:16:51 PM PDT by Mr. Mojo
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To: Mogollon
"What was the mutagenic agent that caused this specific mutation? "

Replication.

183 posted on 07/03/2006 5:28:26 PM PDT by b_sharp (There is always one more mess to clean up.)
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To: microgood
"Seems kind of unfair, though."

Now you know why mice are so prolific.

184 posted on 07/03/2006 5:38:57 PM PDT by b_sharp (There is always one more mess to clean up.)
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To: Billthedrill
There was a time when you could hold a substantive discussion of this sort of thing on FR

That must have been in the year between us.
The thread hijackings have been occurring ever since I've been here.
I've suggested a "science forum" where threads like this can be posted.
I don't think it would be effective though unless there was enforcement by a science forum mod.
It does make me wonder if the science folks ever go to the religion forum to attempt hijackings.

185 posted on 07/03/2006 5:46:29 PM PDT by ASA Vet (3.03)
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To: stands2reason

Easy. If the evidence is not *unique*, then you only have the basis for a *preference*, not a claim of being 'scientific'.

Scientific *facts* are indisputable. Scientific 'preferences' are merely that, preferences. They are a choice based on belief. Evolution is a choice based on belief. Don't pretend otherwise.

You claim that 'everything can be made to fit the design paradigm'. So how is evolution different? What can't be made to fit the 'evolutionary paradigm'?

You have trapped yourself. You can either admit that the 'evolutionary paradigm' is no different from the 'design paradigm' and 'explains everything' *or* you can provide evidence which is not explained by the 'evolutionary paradigm', in which case you are arguing against your own position.

Which is it?


186 posted on 07/03/2006 5:52:42 PM PDT by GourmetDan
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To: GourmetDan
"As for 'vestigal' organs, do you think that 'loss of function' is evidence *for* evolution? That's decline. Much more consistent w/ creation than evolution."

So the loss of hind limbs in a whale is a sign of decline? How so?

"Any way to convince someone like you (who believes that loss of function = evolution) that 'evolution' isn't true? "

Evolution has no direction. If a loss of limbs increases an organisms reproduction success that is not a decline. You have swallowed the 'information' canard hook line and sinker.

Relative Information content
..............................billion base pairs.....chromosome number
Homo sapien sapien..................3.5.............46
Gorilla gorilla..............................4.16............48
Monodelphis dimidiata...............4.17............18 (Short-tailed opossum)
Macropus parma......................4.92............16 (Parma wallaby)
Terrapene carolina..................4.18............50 (Eastern box turtle)
Myxine glutinosa....................4.29............28 (Hagfish)
Galeocerdo cuvier...................3.79............86 (Tiger shark)
Bufo alvarius.......................5.65............22 (Colorado river toad)

It appears as though we ultra complex humans have less 'information' in our genome than quite a number of other organisms. Perhaps the 'amount' of information is not all that important? What are the implications of this in regards to a loss of limb?

187 posted on 07/03/2006 5:54:30 PM PDT by b_sharp (There is always one more mess to clean up.)
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To: doc30

Multiple species form a 'kind'. Dogs, coyotes and wolves are separate species but the same 'kind'. They can all interbreed. This is not counter to prevailing creationist.

Since you can't test your hypothesis that snakes w/ legs and snakes without cannot interbreed, you have no *scientific* basis for your position that they are a separate 'kind'.

And you are *assuming* that legs 'evolved' first and then were lost. It is much more consistent w/ observation that they were *created* first and then lost. Species losing function is easily observed. Species 'evolving' legs is not observed.

When you say that 'you have to look at the whole genetic heirarchial history', then you are imposing your *beliefs* on a set of evidence.

I know that's what you must do. I'm just trying to get you to understand that's what you're doing.


188 posted on 07/03/2006 5:59:51 PM PDT by GourmetDan
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To: GourmetDan
I know that's what you must do. I'm just trying to get you to understand that's what you're doing.

That is why science develops multiple, independent lines of evidence.

189 posted on 07/03/2006 6:03:20 PM PDT by js1138 (Well I say there are some things we don't want to know! Important things!")
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To: stands2reason

"On the outside looking in..."

It looks more like you are on the inside watching a terrorist gang taking over.


190 posted on 07/03/2006 6:07:54 PM PDT by furball4paws (Awful Offal)
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To: b_sharp

The 'evolution has no direction' claim is a compromise to get the theory to match the evidence. This allows 'loss of function' (which is easily observed) to be passed off as 'evolution' instead of the decline that it actually represents. The little evos never know the difference.

It also appears that you have swallowed the 'DNA controls all' canard hook, line and sinker. The evidence now shows that bacteria under stress speed up the mutation of their DNA in an effort to create a genetic combination that can survive the new environment. This is evidence that 'the cell controls the DNA database' and not the other way around.

Now, if DNA controls, how did such a complex process become encoded within the very system that is being manipulated? Do you just believe *everything* you are told without question?

Is there *any* point in examining the realities of biological complexity and interrelationship of systems where you can simply recognize that they cannot develop without intelligent input or are you so committed to the naturalistic paradigm that you will accept any unobserved absurdity as the gospel truth?

Apparently so.


191 posted on 07/03/2006 6:11:08 PM PDT by GourmetDan
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To: Billthedrill

Sorry, but post #3 already took the thread down the path to "another infantile crevo pissing contest"


192 posted on 07/03/2006 6:11:44 PM PDT by villagerjoel (US of A!!!)
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To: js1138

Wrong.

There are no 'multiple, independent lines of evidence'.

They are 'multiple, related lines of interpretation of evidence' because they are *all* based on the same initial assumption (i.e., that the explanation *must* be natural).

You do understand that, right?

The real question is, do you understand the implications?

That I doubt.


193 posted on 07/03/2006 6:14:14 PM PDT by GourmetDan
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To: Tokra
[ You mean like the different bacteria that have evolved to make themselves immune to anti-biotics? The immunity that wasn't in their genetic code before, but is now? ]

Thats not evolution its mutation... same with Darwins Finches..

194 posted on 07/03/2006 6:17:38 PM PDT by hosepipe (CAUTION: This propaganda is laced with hyperbole..)
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To: GourmetDan
They are 'multiple, related lines of interpretation of evidence' because they are *all* based on the same initial assumption (i.e., that the explanation *must* be natural).

That is a characature, but it is close enough to a definition of science: The search for natural explanations, as opposed to the acceptance of supernatural explanations.

Without such an assumption, we would still be explaining volcanos and earthquakes as the rumblings of an angry god or gods. Same for storms and disease and the movements of the planets.

195 posted on 07/03/2006 6:20:36 PM PDT by js1138 (Well I say there are some things we don't want to know! Important things!")
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To: stands2reason
Do you think the structure of the eye disproves evolution?

I don't think it undermines "development", per se. Yet there's something
wonderful in nature having brought forth both reproduction and eyes -
with no evidence for "evoluton" - from the beginning.

I think and believe it's God.

196 posted on 07/03/2006 6:21:46 PM PDT by onedoug
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To: js1138
Entering the twilight zone of pure speculation: humans experience color temperature as a banded gradient. It is fairly easy to demonstrate that the bands of the rainbow have no object reality, and yet we see seven or so fairly distinct bands. If color information is coded as neural firing rates, the bands could be heterodynes.

From what I understand, color perception involves the ratio between the stimulation of the photoreceptors, not the direct intensity of light reception of an individual receptor.

I could not tell you about what a rainbow would look like to a red-green colorblind individual. One experiment you could try to do is load a high color quality photo of a rainbow into some good image editing software and manipulate the redcs and greens so they are the same color. I used to have links to websites that simulate what a colorblind person sees.

197 posted on 07/03/2006 6:45:14 PM PDT by doc30 (Democrats are to morals what and Etch-A-Sketch is to Art.)
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To: villagerjoel
LOL! Yeah, while I was typing my reply there were not five, but 13 posts! It's what I get for disobeying my own rule not to frequent these threads but I do love science news.

What gets to me is the constant acrimony, the sniping, the mischaracterization of other people's points, the denigration, the sheer incivility. There have been other topics that generated this sort of behavior, notably the Terry Schiavo thing, the Elian Gonzalez affair, several different Civil War topics, and quite awhile back an attempt by some particularly nasty and persistent religious fundamentalists to turn FR into a fire-and-brimstone tent show. Those passed as some of the offenders were shown the cyber-door. Perhaps this one will too.

198 posted on 07/03/2006 6:48:23 PM PDT by Billthedrill
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To: GourmetDan

"The real question is, do you understand the implications?"

I'm sure I do, but why don't you enlighten us?


199 posted on 07/03/2006 6:49:23 PM PDT by furball4paws (Awful Offal)
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To: doc30

Neurons (and photoreceptors are neurons) tend to code events as a change in firing rate. All neurons have a quiescent firing rate.

If you tickle the retina with flickering light you get subjective colors

http://www.google.com/search?sourceid=navclient&ie=UTF-8&rls=GGLG,GGLG:2005-31,GGLG:en&q=benham+colors

I'm thinking the flicker rate that produces the experience of color must be related to the firing rate that would produce the "true" experience of color. I did some work on this in college, but it's an incredibly difficult field.


200 posted on 07/03/2006 6:54:29 PM PDT by js1138 (Well I say there are some things we don't want to know! Important things!")
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