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View Poll Results: The Dress: What color do you see?
Black and blue 23 36.51%
White and gold 33 52.38%
Other 7 11.11%
Voters: 63. You may not vote on this poll

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Old 03-16-2015, 03:49 AM   #61 (permalink)
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What Seamus and Rosa wrote is absolutely correct but I always wondered whether we do experience evolution on our eyes due to 'technology'

In the past having bad eyesight would have meant that you can't hunt/work productively = can't provide for a family/feed yourself = don't produce offspring = genes for bad eyes are an evolutionary disadvantage

We had glasses since the middle ages and they were more readily available since a few hundered years now so having bad eyes no longer prevents you from having a job and therefore kids. Wouldn't that mean that the bad eyes genes are now more likely to be passed on?
I know that seeing more people with glasses in modern times is obviously a function of more testing & cheap access to glasses, but some of my friends are seriously blind without them and I can't imagine them functioning in a medieval society let alone as a hunter/gatherer.
Thoughts?
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Old 03-16-2015, 07:53 AM   #62 (permalink)
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Originally Posted by Lanfear View Post
What Seamus and Rosa wrote is absolutely correct but I always wondered whether we do experience evolution on our eyes due to 'technology'

In the past having bad eyesight would have meant that you can't hunt/work productively = can't provide for a family/feed yourself = don't produce offspring = genes for bad eyes are an evolutionary disadvantage

We had glasses since the middle ages and they were more readily available since a few hundered years now so having bad eyes no longer prevents you from having a job and therefore kids. Wouldn't that mean that the bad eyes genes are now more likely to be passed on?

I know that seeing more people with glasses in modern times is obviously a function of more testing & cheap access to glasses, but some of my friends are seriously blind without them and I can't imagine them functioning in a medieval society let alone as a hunter/gatherer.
Thoughts?
Seems sensible enough. The point I was trying to make is that *maybe* the reason you see so much bad eye sight nowadays isn't because we are inheriting bad eye genes (tho presumably this must happen a bit for the reasons you outline), but simply because we are staring at screens (and books) all the time and its fucking our eyes up (the same way running fucks up your knees):

let me try this one more time. If you are near-sighted, you have a hard time focusing on things that are far away (your focal range is only things very near to you). Near-sightedness is far more common than far-sightedness. in order to focus on near things, you must bend your lens (the disk inside your eyeball... it physically changes shape to help you bring things into and out of focus.. i.e it bends).

My hypothesis was that the increased prevalence of near-sightedness arose because we now spend so much time focusing on near things (our screens and books) and as a result our lenses get stuck in that bent position and have a hard time unbending. in cave-man days they didn't have iproducts or books, and they probably spent a lot more time dynamically adjusting their focus to both look at near things (like each other) and to look at far things (like predators and big-game on the horizon). the difference would be frequency of bending and unbending... keeping it flexible, like a tight little underage gymnast. If this is all the case, then cave-men probably had better vison on average, not so much because they were genetically selecting for it, but rather because of how they used their eyes.

but this is all wild speculation. maybe there are genes for bad vision. must be a bit of that. maybe im totally full of shit. probably.
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Old 03-16-2015, 08:05 AM   #63 (permalink)
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Originally Posted by seamus View Post
But of course an animal can be changed by their environment, but those changes aren't passed down to their offspring. Take circumcision, no matter how many generations cut off the foreskin, the DNA for the foreskin isn't removed.

I understand 100% that you are trying to teach poor piff here the basics. but what happened to mr. stickler? how about epigenetic changes (environmental experience-driven modifications to your DNA)? those can be totally heritable... they just wash out after a couple generations. and they are a relatively recent discovery. but real none-the-less.

some things that cause epigenetic changes:

- mother's diet
- mother's stress level during gestation

You can acquire epigenetic modifications to your own DNA through your own experiences, and those then influence the expression of your own genes for the rest of your life.

basically, parts of your DNA get permanently locked up so certain genes can't be expressed.

say, genes for certain stress hormones. young victims of verbal and physical abuse grow up to have highly-stereotyped epigenetic binding patterns on genes for specific stress response hormones...

its super fucked up, but also super cool.

these modifications can sometimes be inherited for a couple generations, but then they go away. so they aren't permanent to the gene pool.

ok byeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee
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Old 03-16-2015, 08:31 AM   #64 (permalink)
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Originally Posted by Rosa View Post
..people who are severely clinically depressed actually do see the world as less saturated. people use metaphors, like "the world is gray,"
Going back to depression affecting sight.

I wonder if depressed people see less saturation because that forces them to migrate to sunnier/ happier/ more vitamin D/ sunshine happy environs?

Just a thought. Also, what exactly is saturation?
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Old 03-16-2015, 08:37 AM   #65 (permalink)
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Originally Posted by Lanfear View Post
I know that seeing more people with glasses in modern times is obviously a function of more testing & cheap access to glasses, but some of my friends are seriously blind without them and I can't imagine them functioning in a medieval society let alone as a hunter/gatherer.
Thoughts?
As someone who wears glasses I think about this all the time.

I also think it's hilarious, (that here in the States) popular culture has adopted wearing big black frames, (with no lenses/ no prescription) just to appear cool/ smart. They do this shit in Germany?
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Old 03-16-2015, 08:58 AM   #66 (permalink)
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Originally Posted by Enunciated Piffle View Post
Going back to depression affecting sight.

I wonder if depressed people see less saturation because that forces them to migrate to sunnier/ happier/ more vitamin D/ sunshine happy environs?
Interesting theory!
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Old 03-16-2015, 09:56 AM   #67 (permalink)
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Originally Posted by Rosa View Post
I understand 100% that you are trying to teach poor piff here the basics. but what happened to mr. stickler? how about epigenetic changes (environmental experience-driven modifications to your DNA)? those can be totally heritable... they just wash out after a couple generations. and they are a relatively recent discovery. but real none-the-less.

some things that cause epigenetic changes:

- mother's diet
- mother's stress level during gestation

You can acquire epigenetic modifications to your own DNA through your own experiences, and those then influence the expression of your own genes for the rest of your life.

basically, parts of your DNA get permanently locked up so certain genes can't be expressed.

say, genes for certain stress hormones. young victims of verbal and physical abuse grow up to have highly-stereotyped epigenetic binding patterns on genes for specific stress response hormones...

its super fucked up, but also super cool.

these modifications can sometimes be inherited for a couple generations, but then they go away. so they aren't permanent to the gene pool.

ok byeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee
I first heard about epigenetics a few days ago in a YouTube video - fascinating stuff.

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Old 03-18-2015, 02:28 AM   #68 (permalink)
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I worried I would get long winded.
Apparently your worries about that post were well founded.
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Old 03-18-2015, 07:40 AM   #69 (permalink)
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Rosa, did you talk yet about tribes in the deep jungle aren't able to distinguish between blue and green because they haven't created the category of "blue"?
!!!!! I actually received an email last night with this link about that study:
Language Log » Himba color perception

It turns out that result was totally fabricated by the documentary film makers. That tribe CAN distinguish blue and green, they are just much slower to detect green on a blue background because they lack the color term. We have known for a long time that language influences our sensitivity to color category boundaries. In Russian there are two really distinct words for blue and light blue (akin to our words for red and pink--pink really is just light red). As a result, Russian speakers can more quickly and accurately detect light blue on a blue background than English speakers. But that doesn't mean English speakers can't see light blue. It's the same with that tribe. The problem is the film makers either didn't get this subtlety or just decided to fucking lie. It's kind of shocking really.
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Old 03-18-2015, 02:02 PM   #70 (permalink)
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Seems sensible enough. The point I was trying to make is that *maybe* the reason you see so much bad eye sight nowadays isn't because we are inheriting bad eye genes (tho presumably this must happen a bit for the reasons you outline), but simply because we are staring at screens (and books) all the time and its fucking our eyes up (the same way running fucks up your knees):

let me try this one more time. If you are near-sighted, you have a hard time focusing on things that are far away (your focal range is only things very near to you). Near-sightedness is far more common than far-sightedness. in order to focus on near things, you must bend your lens (the disk inside your eyeball... it physically changes shape to help you bring things into and out of focus.. i.e it bends).

My hypothesis was that the increased prevalence of near-sightedness arose because we now spend so much time focusing on near things (our screens and books) and as a result our lenses get stuck in that bent position and have a hard time unbending. in cave-man days they didn't have iproducts or books, and they probably spent a lot more time dynamically adjusting their focus to both look at near things (like each other) and to look at far things (like predators and big-game on the horizon). the difference would be frequency of bending and unbending... keeping it flexible, like a tight little underage gymnast. If this is all the case, then cave-men probably had better vison on average, not so much because they were genetically selecting for it, but rather because of how they used their eyes.

but this is all wild speculation. maybe there are genes for bad vision. must be a bit of that. maybe im totally full of shit. probably.
guys! Nature published an article TODAY shedding new light on the whole thing!

"The myopia boom
Short-sightedness is reaching epidemic proportions. Some scientists think they have found a reason why."

The myopia boom : Nature News & Comment

looks like I was wrong: "...scientists are beginning to find answers. They are challenging old ideas that myopia is the domain of the bookish child and are instead coalescing around a new notion: that spending too long indoors is placing children at risk"


"For many years, the scientific consensus held that myopia was largely down to genes. Studies in the 1960s showed that the condition was more common among genetically identical twins than non-identical ones, suggesting that susceptibility is strongly influenced by DNA1. Gene-finding efforts have now linked more than 100 regions of the genome to short-sightedness.

But it was obvious that genes could not be the whole story. One of the clearest signs came from a 1969 study of Inuit people on the northern tip of Alaska whose lifestyle was changing. Of adults who had grown up in isolated communities, only 2 of 131 had myopic eyes. But more than half of their children and grandchildren had the condition. Genetic changes happen too slowly to explain this rapid change — or the soaring rates in myopia that have since been documented all over the world (see 'The march of myopia'). “There must be an environmental effect that has caused the generational difference,” says Seang Mei Saw, who studies the epidemiology and genetics of myopia at the National University of Singapore.

There was one obvious culprit: book work. That idea had arisen more than 400 years ago, when the German astronomer and optics expert Johannes Kepler blamed his own short-sightedness on all his study. The idea took root; by the nineteenth century, some leading ophthalmologists were recommending that pupils use headrests to prevent them from poring too closely over their books.
...
Researchers have consistently documented a strong association between measures of education and the prevalence of myopia. In the 1990s, for example, they found that teenage boys in Israel who attended schools known as Yeshivas (where they spent their days studying religious texts) had much higher rates of myopia than did students who spent less time at their books4. On a biological level, it seemed plausible that sustained close work could alter growth of the eyeball as it tries to accommodate the incoming light and focus close-up images squarely on the retina.

Attractive though the idea was, it did not hold up. In the early 2000s, when researchers started to look at specific behaviours, such as books read per week or hours spent reading or using a computer, none seemed to be a major contributor to myopia risk. But another factor did. In 2007, Donald Mutti and his colleagues at the Ohio State University College of Optometry in Columbus reported the results of a study that tracked more than 500 eight- and nine-year-olds in California who started out with healthy vision. The team examined how the children spent their days, and “sort of as an afterthought at the time, we asked about sports and outdoorsy stuff”, says Mutti.

It was a good thing they did. After five years, one in five of the children had developed myopia, and the only environmental factor that was strongly associated with risk was time spent outdoors. “We thought it was an odd finding,” recalls Mutti, “but it just kept coming up as we did the analyses.” A year later, Rose and her colleagues arrived at much the same conclusion in Australia7. After studying more than 4,000 children at Sydney primary and secondary schools for three years, they found that children who spent less time outside were at greater risk of developing myopia...."

check out the article for more details!
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