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Seeing Stars

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#1 Otto Piechowski

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Posted 07 October 2013 - 10:18 AM

Our eyes can see the stars. Is there an evolutionary reason (advantage) for this having happened? Or, is the fact we can see the stars just a nice side benefit of the type of vision evolution gave us for other reasons?

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#2 PeterR280

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Posted 07 October 2013 - 11:15 AM

our eyes are sensitive to light. Stars emit light in the visible segment. We happen to be most sensitive to yellow light which is the strongest wavelength for sunlight. that was the evolutionary contribution. If the sun had the strongest emission in infrared, we would be sensitive to infrared.

#3 GregLee1

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Posted 07 October 2013 - 11:50 AM

Tough question. There might be some connection between star gazing and the development of rod vision for seeing in dim light, and in turn to escaping predators or hunting at night.

#4 GlennLeDrew

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Posted 07 October 2013 - 02:47 PM

We see stars merely because they happen to be near enough. If our solar system was located in intergalactic space, we would have evolved the same degree of night vision, but all we would see with eyes alone in the night sky, besides the Moon and planets, might be a couple or few little fuzzy galaxies.

#5 Mxplx2

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Posted 07 October 2013 - 03:52 PM

I imagine the three-toed sloth can see the stars also with its eyes, and that doesn't seem to have done much for him (or her).

#6 Jarad

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Posted 07 October 2013 - 05:40 PM

We evolved eyes that see in the visible spectrum because those wavelengths are available from the nearest star - the sun. I don't think that seeing distant stars offers much advantage, but since they tend to emit in similar wavelengths as the sun, it's a "freebie".

Note that some animals have evolved the ability to see in infra-red (pit vipers) and ultra-violet (many insects). So there is nothing magic about the human visible spectrum - we could have evolved sensitivity to wavevlengths slightly above or below what we have. It's get harder to go extremely far out of our range due to chemistry - you have to have a chemical receptor that will capture photons of the wavelengths we see. Extremely long waves (radio or lower) don't have enough energy to change a chemical bond, and extremely short waves (x-ray and higher) have so much that they tend to destroy the chemical when they are absorbed, or just pass right through.

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