How come we all have the same colored palms???

[Afro]

I know this has probably been brought up before, but how come people of all races all have white palms??? Meaning, how come blacks, Indians, Asians, etc etc etc don't have the same colored palms as there regurlar skin???

I never really thought about this until I saw it on a different race board the other day, I've been thinking about it ever since.

[AWAR]

Talking out of my ass:

It's most probably because there's no pigment whatsoever in the palms, because it's a different type of skin, tough, suitable for handling things, sharp rocks, food, basketballs, beer jugs ;D

[Graeme]

Afro, you forgot the soles of the feet. Actually the palms and soles do differ in colour slightly.

Talking out of my red furred, forked tail, I would say that originally humans were dwellers of heavily shaded forests in the tropics. My sake, I think I am heading towards Said ibn Haram's tropical African disease syndrome. And in those shaded, warm tropical forests very dark pigmentation was not needed. For example, Pygmies in African forests and Dyaks in the forests of Kalimantan are much lighter in skin pigmentation than those people who live in the full bore of the sun. I don't know what colour those proto humans were, say, yellowish brown. When the proto humans had to leave this Eden because of climate change and moved into the full bore sun they gradually got darker, but the palms and soles which never or hardly ever face the sun did not need to be protected against the UV in sunlight. Think about it, when you walk your hands are semi closed and inwards towards the sides of the body. One then has to assume that the group that became negroid aka tropical Africans for Said's sake, stayed in the intense tropical sunlight whereas the people who became caucasians and mongoloids retained the yellowish brown pigmentation until moving to areas of very low light intensity.

Or maybe it is just natural selection working out that it is a waste of melanocytes and melanin to put them in places where they would never be used. Afterall how many people do you see specifically sunning their palms and soles.

[nordicyouth]

Some more ass-talk: maybe it's so that when people surrender at night and raise their hands, they will be visible in the darkness...just a thought... ;D

[AWAR]

Graeme said:

Afro, you forgot the soles of the feet. Actually the palms and soles do differ in colour slightly.

Talking out of my red furred, forked tail, I would say that originally humans were dwellers of heavily shaded forests in the tropics. My sake, I think I am heading towards Said ibn Haram's tropical African disease syndrome. And in those shaded, warm tropical forests very dark pigmentation was not needed. For example, Pygmies in African forests and Dyaks in the forests of Kalimantan are much lighter in skin pigmentation than those people who live in the full bore of the sun. I don't know what colour those proto humans were, say, yellowish brown. When the proto humans had to leave this Eden because of climate change and moved into the full bore sun they gradually got darker, but the palms and soles which never or hardly ever face the sun did not need to be protected against the UV in sunlight. Think about it, when you walk your hands are semi closed and inwards towards the sides of the body. One then has to assume that the group that became negroid aka tropical Africans for Said's sake, stayed in the intense tropical sunlight whereas the people who became caucasians and mongoloids retained the yellowish brown pigmentation until moving to areas of very low light intensity.

Or maybe it is just natural selection working out that it is a waste of melanocytes and melanin to put them in places where they would never be used. Afterall how many people do you see specifically sunning their palms and soles.

That makes a lot of sense.
Btw. Why are gorillas pitch black, palms and all?

[Graeme]

Gorillas! Is that so? Now that is a subject I definitely do not know much about. Never seen one especially its palms. They do belong to a different Genus maybe that has something to do with it. The gorilla has a bone in its penis, humans don't, gorilla males have a cranial crest, humans don't either. I guess that is the wonder of evolution and natural selection or for believers, God's handiwork.

[zain]

When the proto humans had to leave this Eden because of climate change and moved into the full bore sun they gradually got darker, but the palms and soles which never or hardly ever face the sun did not need to be protected against the UV in sunlight. Think about it, when you walk your hands are semi closed and inwards towards the sides of the body.

I don’t think it is true ,If that is true then their ass, and their under arms will be whiter than their palms and their soles (it is very will covered and protected by their butt, or arms)
I think facing the sunlight does not have a “direct” influence in human genetic changes ,it has indirect influence through natural selection.
what happens is random mutation filtered by natural selection, shape variance human skin colors .
In the case of palms and soles there must be something that made natural selection in favored with thick skin palms which means different type of skin cells, that were unable to produce melanin .

[sublime]

A. Layers The five layers are (from deep to superficial):

1. Stratum Germinativum (Basale) — Attached to basement membrane, forms epidermal ridges that meet dermal papillae beneath, and contours of skin follow those ridge patterns, forming fingerprints, for example, on palms. (Fingerprints, aka dermatoglyphs, are present on palms and soles of primates only, they develop during fetal months 3-4, are genetically determined, are unique, and do not change during life.) Mitotic layer.that continually divides to push cells superficially (where they move and change, differentiating to keratinocytes, to become cells of the remaining four layers sequentially, progressively moving toward the surface to be sloughed off). Some basale cells also migrate deep into the dermis (underlying CT) to become sweat and oil glands and hair follicles (all epithelial/epidermal derivatives).

2. Stratum Spinosum — These continue division and increase the thickness of the epidermis.

3. Stratum Granulosum — When cells reach this stage, they have stopped dividing and have started laying down keratin and cells become flatter and less permeable. More superficially in this layer, cells are degenerating, dying and losing their nuclei- WHY? (Hint: epithelium is avascular, the underlying dermis provides the nutrition.)

4. Stratum Lucidum — This is the EXTRA layer (the fifth layer) present only on hairless skin of the palms and soles. This is a clear, glassy, tough layer that gives the palms and soles a lighter color, particularly on darkly-pigmented skin.

5. Stratum Corneum — About two to four weeks from their origin in stratum germinativum, cells reach this layer. They are dead and may remain on the surface for about another two weeks before being shed or abraded off.

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B. Skin Color — Basically due to three pigments: melanin (in epidermis) and carotene (in epidermis and dermis) and hemoglobin (in blood capillaries of the dermis). Skin color can also be diagnostic, as in cyanosis (blue hue), jaundice (yellowed skin), or erythema (redness).

1. Melanin: Melanin is produced by specialized melanocytes in the stratum germinativum that pass their melanin to keratinocytes. Although melanocyte concentration varies in different regions of the body, all people (regardless of race) have approximately equal number of melanocytes. Differences in brown color relate to differential melanin production (a genetic feature) by those cells. Freckles and liver spots are benign clusters of melanocytes. UV exposure increases melanin production. What is the function of melanin? To protect you from harmful UV rays which can damage DNA, causing mutations and promoting cancer development. (Limited UV exposure is needed, however, for production of vitamin D3.) GET OUT OF THOSE TANNING BEDS, and USE THAT SUNSCREEN!

2. Carotene is a yellow pigment that is a precursor of vitamin A that gives some people's epidermis a yellowish or olive tint, it also found in fatty tissues of the dermis.

3. Hemoglobin: In lightly-pigmented individuals, hemoglobin (a red pigment in red blood cells) can be seen from their dermis, through their transparent epidermis, giving them a "pink" tint.

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Source

[Melnorme]

Three cheers for Sublime.

[darksphere]

Thanks for the info, Sublime!

I was just about to say that the skin on the palms were different. But your posts is much more specific then what i could have wrote.

I think the subject of pigmentation is interesting. So please do share your knowledge.

And cool avatar too... Hitman is a Scandinavian produced game!

[Afro]

Thanks alot Sublime.

Yeah I thought that it might have something to do with different skin but wasn't sure.

[Graeme]

Thank you, sublime. I know I will never look at my palms again without thinking about my strata lucida or Awar's gorillas. My palms and soles are red in keeping with my nature!

Afro, have you noticed how everyone's insides look the same, all high pinks and purplish shades, we are the same species you know.

[darksphere]

Graeme said:

Afro, have you noticed how everyone's insides look the same, all high pinks and purplish shades, we are the same species you know.

Deers, dogs and dolphins are pink and purplish inside too. So that's a rather moot argument.

Allthough you're right that we are the same species(including Gorillas, Chimpanzees and Orangutangs probably).

Speaking of Gorillas I'm not so sure that they don't have light palms. The ones I've seen had grey palms. It's impossible to say, I think, what colour the rest of their body has seeing as they have hair all over.
If they are pitch black on the rest of the body that would mean they did have lighter palms.

Now that we know the lighter palm derives from an extra protective layer in the skin it seems likely that gorillas should have such an extra layer too. After all they walk much more on their palms than the rest of us.

[zain]

good one Sublime ,


here is some gorillas
www.geocities.com/human_evolution2002/gorallchw.jpg
www.geocities.com/human_evolution2002/fthrson.jpg


a nice chimpanze
www.geocities.com/human_evolution2002/fowrchmz.jpg

[sublime]

A cast of a gorilla palm. It looks remarkably similar to the human palm.