possibility check: more diverse eye colours in humans

Berus

Humans do already have quite diverse eye colours, ranging from brown, to blue, green to gray. amber, hazel etc
but could it be possible, that humans (maybe due to a mutation) can get orange or yellow eyes.
from what i know, blue eyes didnt exist naturally within humans, its rather a mutation which managed to endure.
so what about yellow or orange eyes ? could those be doabe due to a mutation aswell ?
 

Zuvarq

Some green eyes look yellow.

And some amber/hazel eyes look orange.

Actually-yellow or orange eyes are probably not possible since those pigments are not available in humans. Blue eyes are just a lack of melanin, not an actual blue coloring.
 
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whitecrow

Banned
Get a stable population of humans that for whatever reason become albino. You can end up with individuals who have red/red-ish or even purple eyecolor.

tumblr_lixotwvdNs1qitj5zo1_400.jpg
 

Mongo

We had a thread like this a few months ago. Basically, human eye colours are due to concentrations of two pigments (melanin and lipochrome) and the type of scattering in the stroma (outer iris).

Eyes without pigment will range from blue when Rayleigh scattering dominates (this is what makes cloudless skies blue) to grey when Mie scattering dominates (this is what happens under cloudy skies). Raleigh scattering happens when the stroma is less turbid, while Mie scattering involves greater turbidity.

If melanin is absent, but lipochrome is present, then the eye colour ranges from amber (Mie scattering dominant) to green (Raleigh scattering dominant). If melanin is present in large amounts, then the eye colour ranges from brown (Mie scattering dominant) to black (Raleigh scattering dominant). If melanin is present only in small amounts, then eyes with Mie scattering dominant with be light brown and with Raleigh scattering dominant will be hazel.

PIGMENTS : MIE SCATTERING / RALEIGH SCATTERING

neither pigment : grey / blue
only lipochrome : amber / green
some melanin : light brown / hazel
more melanin : dark brown / black
 

The Uchronian

Berus said:
Humans do already have quite diverse eye colours, ranging from brown, to blue, green to gray. amber, hazel etc
but could it be possible, that humans (maybe due to a mutation) can get orange or yellow eyes.
from what i know, blue eyes didnt exist naturally within humans, its rather a mutation which managed to endure.
so what about yellow or orange eyes ? could those be doabe due to a mutation aswell ?
Click to expand...

Actually, blue eyes probably were around from the very start of modern humanity; did you know, for example, that blue-eyed people were talked about in ancient Persia, long before any European knew the place even existed?

Orange or yellow eyes, OTOH, probably would come around as a result of a more recent mutation, though I'm not sure exactly how that would come around.
 

Tripwire

Rainbow Sparkle said:
That makes me wonder if someone who is the child of an Albino parent could theoretically not be albino, but possess the eye color of one.
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No, because the eye color comes from the Albinism. It's just the blood vessels being seen through the clear or nearly-clear iris. Human albinos usually have eyes that are more blueish than red anyway.

I'm not going to say it's impossible, but I'm skeptical that orange or yellow eyes could arise through a mutation. Blue eyes and green eyes exist because of a mutation that limits the expression of melanin in the eye, to get orange or yellow you'd have to have a mutation that adds pigment, which seems unlikely.
 
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Berus

ok i see.
hmm, but what about a population of black people, who have more blue eyes or light eyes than common, perhaps about 14% blue eyes of the whole population, 50% light brown eyes, and the rest dark brown. so those people would be dark colored, but their eyes would most of time be rather light colored.
even though its rare, some black people do actually have blue eyes.
 

Tripwire

Berus said:
ok i see.
hmm, but what about a population of black people, who have more blue eyes or light eyes than common, perhaps about 14% blue eyes of the whole population, 50% light brown eyes, and the rest dark brown. so those people would be dark colored, but their eyes would most of time be rather light colored.
even though its rare, some black people do actually have blue eyes.
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This would be entirely possible, except that blue eyes in a really sunny environment like Africa would be slightly deleterious for the same reason pale skin would be. There's a reason this mutation arose and spread from Northern Europe.

Black people with blue eyes are due to European admixture. All evidence points to everyone with blue eyes being the descendant of one individual.
 

Tripwire

Zuvarq said:
Actually blue eyes and blond hair independently evolved among Melanesians and Aboriginal Australians. Both of which are black.
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What's your source on Melanesians with blue eyes? I can't find anything, and the blonde hair in Melanesians has nothing to do with their eye color.
 

The Uchronian

Zuvarq said:
Actually blue eyes and blond hair independently evolved among Melanesians and Aboriginal Australians. Both of which are black.
Click to expand...

Yep, very much true. This theory of ALL blue eyes having originated from a single source in Eastern Europe 6-10k years ago, simply holds no water when examined carefully.
 
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Berus

maybe a group of black people migrates nothwards, mixes with a light eyed population. or there is just a higher level of the blue eye mutation amongst them.
 
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The Professor

The Professor

Mongo said:
We had a thread like this a few months ago. Basically, human eye colours are due to concentrations of two pigments (melanin and lipochrome) and the type of scattering in the stroma (outer iris).

Eyes without pigment will range from blue when Rayleigh scattering dominates (this is what makes cloudless skies blue) to grey when Mie scattering dominates (this is what happens under cloudy skies). Raleigh scattering happens when the stroma is less turbid, while Mie scattering involves greater turbidity.

If melanin is absent, but lipochrome is present, then the eye colour ranges from amber (Mie scattering dominant) to green (Raleigh scattering dominant). If melanin is present in large amounts, then the eye colour ranges from brown (Mie scattering dominant) to black (Raleigh scattering dominant). If melanin is present only in small amounts, then eyes with Mie scattering dominant with be light brown and with Raleigh scattering dominant will be hazel.

PIGMENTS : MIE SCATTERING / RALEIGH SCATTERING

neither pigment : grey / blue
only lipochrome : amber / green
some melanin : light brown / hazel
more melanin : dark brown / black
Click to expand...

And if you add in uneven pigmentation and turbidity you get eyes like mine which vary depending on the light and my health
 

Finn

CaliBoy1990 said:
Yep, very much true. This theory of ALL blue eyes having originated from a single source in Eastern Europe 6-10k years ago, simply holds no water when examined carefully.
Click to expand...

But it's likely that the blue eyes of Eurasia came from one population group.
 

The Uchronian

Finn said:
But it's likely that the blue eyes of Eurasia came from one population group.
Click to expand...

Again, I'd like to refer to ancient Persian texts.....texts from an era, btw, long before any European had ever even conceived of the place, let alone visited it.
 

Zuvarq

CaliBoy1990 said:
Again, I'd like to refer to ancient Persian texts.....texts from an era, btw, long before any European had ever even conceived of the place, let alone visited it.
Click to expand...
Well it only makes sense that blue-eyed ancient Persians would descend from the Eurasian blue-eyed common ancestor/ancestral population. Pretty much all the Indo-European peoples look more European than the groups next to them, and Persians are Indo-European.

I was just disputing the idea that all black people with blue eyes are due to European admixture. Of course, all African-descended black people with blue eyes must have had European admixture at some point.
 

The Uchronian

Zuvarq said:
Well it only makes sense that blue-eyed ancient Persians would descend from the Eurasian blue-eyed common ancestor/ancestral population. Pretty much all the Indo-European peoples look more European than the groups next to them, and Persians are Indo-European.
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Yes, they are Indo-European, but again, it doesn't all add up; this population which supposedly singularly gave rise to blue eyes was located in Eastern Europe, a region which saw absolutely no real ethnic contact with the Persian world until at least Roman times.....not to mention that there's no record of eastward migration amongst proto-Romanians in ancient times, either(which would be required).

This theory, as much as some may want to defend it, for whatever reason, simply doesn't hold up against sufficient scrutiny. It would make a nice "What If?", TBH, but in reality, it just isn't so.
 

Zuvarq

CaliBoy1990 said:
Yes, they are Indo-European, but again, it doesn't all add up; this population which supposedly singularly gave rise to blue eyes was located in Eastern Europe, a region which saw absolutely no real ethnic contact with the Persian world until at least Roman times.....not to mention that there's no record of eastward migration amongst proto-Romanians in ancient times, either(which would be required).

This theory, as much as some may want to defend it, for whatever reason, simply doesn't hold up against sufficient scrutiny. It would make a nice "What If?", TBH, but in reality, it just isn't so.
Click to expand...
A massive amount of invaders from the north went to the Middle East including Persia, in ancient times. Before Persia existed.
 
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