Theory on how humans became dark skinned.

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posted on Sep, 6 2013 @ 07:53 PM
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I'm no expert, so if anyone has a better theory please post.

We know that chimps have white skin under their fur. This makes me think that the hairy pre-humans living in Africa also had white skin under their fur. If this species had stayed in Africa I'm guessing they would never have lost the fur as a protection from the sun.

What I propose is that this hairy species migrated out of Africa and into the colder climates. They needed to wear the skins of the animals they killed, and they probably learned how to make fire and keep warm. Over many generations they lost the fur.

Then something happened to send them migrating again. With no knowledge of where their ancestors came from they wound up back in Africa, hairless and in dire need of protection from the sun. Their skinned darkened to provide that protection.

Does this have any merit, do you think?




posted on Sep, 6 2013 @ 08:00 PM
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Hmmmm....i would think it would be selective genetic mutations...?
Darker skin in hotter climates would mean melanin production ,so it is something along those lines ?
I'm just making a comprehensive guess.

I was taught sickle cell anemia is a genetic mutation .
It only affects the black population ,and allegedly its because despite it being a painful disease in the western world ,in Africa ,the sickle shape keeps the malaria germ from taking over cells in the blood to multiply .
So having the disease protects you from malaria ....

Many mutations are good in one place ,bad in another .



posted on Sep, 6 2013 @ 08:09 PM
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reply to post by jiggerj
 

In humans, melanin is the primary determinant of skin hair and iris color.
Where humans originated, or what skin color, or what the climate factors, were at this origin who knows.



posted on Sep, 6 2013 @ 08:11 PM
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reply to post by jiggerj
 


You're going to have to work on this much harder and find evidence that is correlative. Honestly, you're not very close here at all, and I don't have the time to tell you the err of your ways.

Good luck my friend.



posted on Sep, 6 2013 @ 08:12 PM
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Originally posted by Racist
reply to post by jiggerj
 

In humans, melanin is the primary determinant of skin hair and iris color.
Where humans originated, or what skin color, or what the climate factors, were at this origin who knows.


This particular post has TONS of merit and relevance. So, I would suggest that the OP begin to make a study in this direction. There are other factors as well...but, this post is the most useful that I have seen.



posted on Sep, 6 2013 @ 08:13 PM
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reply to post by jiggerj
 


While chimps are born with white skin underneath, they turn darker as they age and the older ones are very dark underneath. I'm not 100% sure on the reasoning for this, but it may be the same as in human pigment change.

Melanin is a natural sunscreen. Before the advent of clothes humans needed this natural protection to block the harmful effects of ultraviolet radiation . . . chimps and other animals don't need this as they have the natural protection of a fur/hair layer. However, melanin production (dark skin) also greatly reduces the amount of Vitamin D sunlight creates through human metabolism, which is needed for health and energy . . . not unlike photosynthesis in plants.

As humans migrated to less "sunny" locales . . . Vitamin D deficiency proves deadly (for dark skinned people) and natural selection of lighter skinned humans take hold creating the differentiation we see today. (Think of this like the ol' Peppered Moth . . . after fires the lighter ones are picked off and darker is more favorable, however when conditions of the bark return to normal . . . the lighter moths gain prominence again.)

EDIT - BTW this is a very simplified version
edit on 9/6/13 by solomons path because: (no reason given)



posted on Sep, 6 2013 @ 08:16 PM
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If you check out the human genome project they can tell you why Asian people look the way they look, why blacks, & whites look the way they look, etc. They traced humans back as far as they could, using DNA of volunteers. They attribute things like eye color, eye shape, hair texture, etc to environmental influences (based on where each race originated from). If I remember right things like lots of snow would have caused a need for eyes to squint more so would have influenced the shape of eyes. Or black eyes as a way to protect the eye in highly reflective areas. I think its now controversial but it's interesting.

This link explains human origins and provides a map

phillipsdnaproject.com...

This link is more about the human genome project where the first link originated.

www.accessexcellence.org...
edit on 6-9-2013 by Dianec because: Provided better link



posted on Sep, 6 2013 @ 08:32 PM
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I believe it has been published that white/light skin races became that way through a genetic mutation. Before the mutation, the majority (maybe all people) were of rather dark skin.

I'll look for the paper on it and post it here when I find it, unless someone knows what I am talking about and posts it first.


_____________________________________________________________________________

The Washington Post




Scientists Find A DNA Change That Accounts For White Skin



By Rick Weiss
Washington Post Staff Writer
Friday, December 16, 2005


Scientists said yesterday that they have discovered a tiny genetic mutation that largely explains the first appearance of white skin in humans tens of thousands of years ago, a finding that helps solve one of biology's most enduring mysteries and illuminates one of humanity's greatest sources of strife.

The work suggests that the skin-whitening mutation occurred by chance in a single individual after the first human exodus from Africa, when all people were brown-skinned. That person's offspring apparently thrived as humans moved northward into what is now Europe, helping to give rise to the lightest of the world's races...





How a Genetic Mutation Led to the White "Race"




By Nadra Kareem Nittle
About.com Guide
January 29, 2011


Imagine a world where everyone had brown skin. Tens of thousands of years ago, that was the case, say scientists at Penn State University. So, how did white people get here?

Evidently, when humans began leaving Africa 20,000 to 50,000 years ago, a skin-whitening mutation appeared randomly in a sole individual. That mutation proved advantageous as humans moved into Europe. Why? Because it upped the amount of vitamin D the migrants had...






edit on 6-9-2013 by esteay812 because: (no reason given)



posted on Sep, 6 2013 @ 08:36 PM
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reply to post by jiggerj
 


Well, we're not directly related to chimps but part of the reason why so many monkeys do have lighter skin underneath their fur is because they are covered with fur really. In areas where the skin is exposed on many species of apes, monkeys, chimps and whatnot, it tends to be dark. It's just a matter of melanin production and fur means less is needed. Since we're not so hairy, we needed more melanin (fair skin is a genetic mutation). That's my guess.



posted on Sep, 6 2013 @ 09:56 PM
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Interesting theory.

Of courese, chimps are not our direct ancestors, but we had a common ancestor at some stage.
Chimps pretty much stayed in the vast forests of Africa, while our ancestors stayed or moved to areas that were replaced by grasslands and more open savannah.
I think this is where the fur was largely lost, and hominids had to evolve to stand erect and run (thus requiring sweat).

There are also many shades of black.
The Khoisan people in southern Africa have very old genetic material, and they are yellowish-brown, rather than black.
The Neanderthals lived in Europe for a very long time, and nobody knows whether they had fur regionally or not.

Just to add on skin-tone: there are accounts of white people kidnapped by natives in the colonial era, or who chose to stay with them, who after a few years had a similar skin-tone to the natives.
Without buildings or clothes I think people can evolve very fast to suit the environment.
edit on 6-9-2013 by halfoldman because: (no reason given)



posted on Sep, 6 2013 @ 10:02 PM
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This is a very interesting thread with excellent explanations. However I am not totally buying them. Can it be proven that the mutations didn't come from a different race?



posted on Sep, 6 2013 @ 10:27 PM
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What do I think?

I think people are awesome. I don't care if you are white, tan, brown black, or any other color.

OP I like the way you think, it's a bit hmmmm.....crazy, but who knows you may be right.



S+F



posted on Sep, 6 2013 @ 10:37 PM
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Naw, humans originally had feathers. Look at your skin then look at a plucked chicken.
We were never chimps, our pinfeathers still cover our heads and a few other parts. We evolved from dinosaurs like animals of some type, that is why we really don't look like any other species. So there were a few mutations that formed things like monkeys and apes. That is what happens when you eat bananas. The testosterone that forms from the bromelaine in the banana causes a guy or gal to get all hairy....but usually a little bald on top


Just kidding
I think. I actually think that humans were originally white myself, the melatonen changes in the skin to darken are more likely than to whiten.



posted on Sep, 6 2013 @ 10:38 PM
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reply to post by rickymouse
 




atsers are so weired.



posted on Sep, 6 2013 @ 11:04 PM
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reply to post by esteay812
 


I agree with you esteay812.

The studies I've read indicate that white skin and blue eyes are mutations from an original dark skin and dark eyes. I'm wondering if the interbreeding between Neanderthals and non sub-Saharan Homo Sapiens is at all related to the mutations.

 


 





reply to post by jiggerj
 


You mention the skin color of chimpanzees. Isn't the skin color of gorillas, bonobos, and orangutans black/dark-brown?

 


I'm thinking that a thread titled "Theory on how humans became light skinned" may be more appropriate.

edit on 9/6/13 by Sahabi because: (no reason given)



posted on Sep, 6 2013 @ 11:21 PM
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I believe the official reasoning is that the apes that were to become humans quit their arborial habitat (ie came down from the trees) and started to hunt on the open savannah.

This incidentally is the biggest mystery.....why would arborial, largely herbivorous creatures change their habitat and start to hunt like carnivores? No one knows. At any rate, that is what is supposed to have happened.

Because they now needed to sprint very fast (both to catch game and to escape other predators), they lost their body hair as a necessary adaptation to lose excessive body heat (though other predators appear to have kept their body hair...?? Another mystery.)

When we lost our hair (presumably in the heat of Africa), our skins darkened as a protection against the sun. And when we left Africa for colder climes, our skin correspondingly lightened again.



posted on Sep, 7 2013 @ 12:06 AM
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reply to post by CJCrawley
 

Apparently our tree-dwelling ancestors had to come down because the landscape changed, and the forests disappeared.

This might have happened gradually, and the distance from one tree to the next increased until it was all savannah.



posted on Sep, 7 2013 @ 12:28 AM
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Once again lots of divergent "theories".

I love the expert quote...."when Humans left Africa 20-50,000 years ago".

Excuse me expert person, but Neanderthals are Humans, and go back as far as 250,000 years in Europe.

Homo Erectus skulls, another Human, have been found in Asia and are 500,000 years old.

So there goes That "Expert"?? theory.....

White people kidnapped turning black.......What Rubbish!!!

My European genes have been in Australia for 178 years, and Im as white as a lilly!!
.
I dont turn black in the Sun, neither do ANY white Europeans in Brown lands.........If we stay in the Sun, we turn bright red, burn, then our skin peels off in sheets.....we are still white underneath. Heaven help you if you are a Redhead....
There is a reason, Australia has one of the highest skin cancer rates, and it not the Dark People that get it.

In any case, how come Pure blood Black African Slave descendants in the North Americas havent turned white?
And they have been there for 400 years.
The only way they turn white, is to breed with a White European, or light coloured Asian person.

Only goes to show once again, you can study the Human genome for 50 years, and still not know the correct answer.

It is all speculation, when it comes to How we are, what we are....

This Wiki entry (for what its worth), tells us that Homo Erectus remains are as old or older than those found in Africa.......And they may have migrate TO Africa from Eurasia (Europe/Asia)....
So what colour were they?? Were the First Africans, really European descendants??
en.wikipedia.org...
edit on 7-9-2013 by gort51 because: (no reason given)



posted on Sep, 7 2013 @ 12:50 AM
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reply to post by halfoldman
 


Yes that's the working theory - the environment changed.

What's strange is it didn't happen to any other ape. The apes today are the same, and have lived the same, for millions of years.

It's assumed that, if the environment changes, the animal would have to adapt to a new one in order to survive. But is this likely?

Imagine if Africa were to lose its forests...would the chimps and gorillas start competing with the lions and hyenas for food on the open savannah? And how successful would that be?

I just find it hard to imagine any ape adapting successfully to a radically different habitat.

I'm not saying it didn't happen (evidently, for us, it did) but it seems highly unlikely. The likely scenario would be that that animal would die out.

There is some mystery here.



posted on Sep, 7 2013 @ 08:00 AM
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Originally posted by jiggerj
I'm no expert, so if anyone has a better theory please post.

We know that chimps have white skin under their fur. This makes me think that the hairy pre-humans living in Africa also had white skin under their fur. If this species had stayed in Africa I'm guessing they would never have lost the fur as a protection from the sun.


Africa wasn't always as hot and dry as it is today. There is geological evidence of heavy rainfall in the Sahara as late as 8000 years ago: dried up lakes and river beds etc. The deserts were fertile grasslands, mountains were forested etc. This was around the end of the ice age, so the climate would have been much cooler then.

The ice age began about 2.6 million years ago. The earliest member of the genus Homo which we know of, Homo Habilis, existed about 2.3 million years ago. Having evolved during a cooling period, it makes sense that they'd be hairy. The hair was probably more useful for heat retention than for protection from the sun, though it would serve that purpose as well.

Now, the earliest known Homo Sapiens lived around 200,000 years ago. That's about 2.4 million years into the ice age, about 90% of the way through. The climate would have been warming up, thus natural selection would favor those who adapt to stay cool, which means losing hair. With significant hair loss comes skin damage from UV exposure, so natural selection would favor those with darker skin to resist UV exposure.





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