Theory on how humans became dark skinned.

reply to post by CJCrawley


Um... maybe it's like all the legends say and some external force popped in and messed with our dna. Neatly explained, heh.

Creationists would be happy, if we change the language a tad and evolutionists are still mainly supported, too, and everyone can leave happy and focus on the future.

And the elder gods would have their due and maybe won't eat us...

reply to post by Galvatron


I'm sure late comers out of Africa would have had less interbreeding with Neanderthals, but as this map below shows there was quite a good amount going on in early Homo Sapiens exodus from Africa. Since what we would call the Chinese as the first exodus then they would have more inbreeding, but one thing to think about is the ice age that extinct the Neanderthals all most extinct us too. If it wasn't for our hunter gatherer instinct to follow the herds south we might also had gone the way of the Neanderthals.

One thing to consider is the bottlenecking of Homo Sapiens around the ice age to drastically reduce the divergent that we would have seen today if the ice age never happened. One thing to consider is Homo Sapiens already branched off into European and Asian before they ran into the Neanderthals, so it would be hard to suggest Neanderthals gave us our white skin.

map

If the evaluation of man started with apes, then what made or caused the apes to stop evolving into man when man became as they are now?

So how did a broad nose and large lips protect them from the sun in Africa?

reply to post by Xtrozero


My understanding is that from a genetic perspective, fair skin, hair, and eyes, are more likely than not inherited from the mixture with Neanderthal. Africans leaving the continent through the Sinai would encounter Neanderthals almost immediately upon entering the Levant and Anatolia. Neanderthals had already been living there for about half a million years. From what I've read, it seems as though Neanderthals were more or less mixed away rather than out-competed, although it's obviously much more complicated that putting their disappearance into either of those two categories completely. It would also explain why there is genetic evidence to suggest that many populations, modern human though they may be, are actually genetically closer to Neanderthal than sub-Saharan black African.

I disagree with your statement that Eurasian populations had already branched off to be distinct before running into Neanderthals. The genetics don't seem to support it. Your map doesn't either. Have you seen what uncontacted tribes in south east Asia look like? They look almost black African. According to your map, if they followed the southern coast they would have had negligible contact, and therefore interbreeding with Neanderthals. Also, according to your map, it would explain why Eurasians tend to have fairer skin.

Adaman Woman form islands in the Indian Ocean.

New Guineans from south east Asia.

Aborigine Man from Australia.

reply to post by jiggerj


JiggerJ, Thanx for This Thought Provoking Post! It is one of the Topics I have been Wondering about a Lot over the Years. I share the same Thought as ATS4Dummies who touched on one of my thoughts. They Stated;
"OK, I guess I'll have to drop the bombshell.
Ready? Blacks ARE native to earth. All other races came from elsewhere and were genetically modified to acclimate to earth. That's why blacks have no neanderthal genes. Now you know." (as in I assume they meant, came from Other Planets), except that I had thought that We ALL were brought here from ElseWhere. However, Possibly Blacks were Brought here First, explaining the longer lineage.
Then as I read all the Good Comments from Others, I was Pissed to see one from XtroZero. Maybe because I am not having one of the best days, weeks even...... They State; "You know what I find stupid is a concept that humans could evolve on another planet with totally different EVERYTHING, there is only one human race, we are unique to earth just like any other life form would be unique to their planet.
Get real..."
I don't see how ATS4Dummies' Comment is a "Stupid" concept. Why would Earth be the only Planet capable of Sustaining Humans? I would think that of the Billions, Trillions of Planets out there that there are a LOT of Planets of Same Composition as Ours. Close enough to, or the Very Same levels of Oxygen, Temperatures, etc., needed for Human, Human-Like Species to exist and Thrive. Why is this Theory Stupid? Even if I didn't share the same thought, I don't like to see someone professing their SelfProfessed God-Status on anyone else. I'm not trying to DeRail the OP, but I don't see AnyThing Stupid about ATS4Dummies' comment. It's no more Stupid than Any Other Concepts Others have Stated. (NO, I don't think any of the Theories Stated are Stupid) Opinions from EveryOne are just That, Opinions. Who is AnyOne to think that THEY are ABOVE AnyOne Else in Matters such as This? I'm no 'Angel' but # like This just Pisses me Off! Apologies for the Rant. Syx.

reply to post by jiggerj


I would be more inclined to ask how did people become light skinned because you can lose melanin but you cannot gain it.

Famouszor
If the evaluation of man started with apes, then what made or caused the apes to stop evolving into man when man became as they are now?

How do i kill myself before i answer one of these questions?

...

Humans shared a common ancestor with apes, Apes are Cousins, our great great great great(..greatx10,000).. grandfather was the same as ape's grandfather.

Famouszor
If the evaluation of man started with apes, then what made or caused the apes to stop evolving into man when man became as they are now?

They are evolving just like us but on a different path. What makes you think man is some higher step in the evolutionary chain that primates would evolve to and not just another type of primate?

reply to post by damwel


Bigger nostrils to breath more air in hotter climates. As far a lips go, I don't know.

Galvatron
reply to post by Xtrozero

 

My understanding is that from a genetic perspective, fair skin, hair, and eyes, are more likely than not inherited from the mixture with Neanderthal. Africans leaving the continent through the Sinai would encounter Neanderthals almost immediately upon entering the Levant and Anatolia. Neanderthals had already been living there for about half a million years. From what I've read, it seems as though Neanderthals were more or less mixed away rather than out-competed, although it's obviously much more complicated that putting their disappearance into either of those two categories completely. It would also explain why there is genetic evidence to suggest that many populations, modern human though they may be, are actually genetically closer to Neanderthal than sub-Saharan black African.

I disagree with your statement that Eurasian populations had already branched off to be distinct before running into Neanderthals. The genetics don't seem to support it. Your map doesn't either. Have you seen what uncontacted tribes in south east Asia look like? They look almost black African. According to your map, if they followed the southern coast they would have had negligible contact, and therefore interbreeding with Neanderthals. Also, according to your map, it would explain why Eurasians tend to have fairer skin.

Adaman Woman form islands in the Indian Ocean.

New Guineans from south east Asia.

These groups from the archipelagos in western Pacific have the most genetic diversity amongst humans, going back 35,000 plus with no Neanderthal interaction. An interesting thing is the naturally blonde genetic variant that is common there.

Another interesting study is one that suggests white people have been around less than 10,000 years, long after Neanderthals went extinct. This suggests that the white skin came from environmental influences, and Scandinavia might be a good example of this. Since white skin absorbs Vitamin D 4 or 5 times better than black skin, then lighter skin mutations would have a better survival rate in areas with little sun. Within a few 1000 years the whiter skin mutations would slowly weed out the darker skin with the higher survival rate and we end up with a situation like Scandinavia where everyone has very white skin and blonde hair.

reply to post by jiggerj


You are assuming evolution is at work here in Humans.. you say pre-humans and indicate these evolved into present day humans.

You simply cannot do that because evolution in humans from other non humans or pre-humans if not a fact based in science - it is only a theory one that has never been proven.

If you look at the worlds peoples and the climate they come from that tells the whole story. Hot ( equator) or cold ( north pole - Eskimos have dark skin) all those people have darker skin than humans who stayed in moderate climates. However there is also American Indians, many of which are as dark as black people. We (whites) are descended from Europeans who are a mixture of many moderate climates for the most part. I think the dominant genes for skin color play a factor here when races mix.

reply to post by jiggerj


No it is called selective breeding bringing forth certain genetic traits while suppressing other traits.
There really is no "race", we are all mankind, we invented the word race, I never seen a completely black person or a completely white person, everyone is a mix of different shades of tan really.

All genetics were there from the time God created Adam and Eve. Adam and Eve were most likely tan skinned, kind of what you see maybe when black and white people have children sometimes. When God split up the peoples into separate languages at Tower of Babel, they separated across the earth into each groups of similar languages of course. This caused the selective breeding for hundreds and thousands of years, which in turn caused certain traits to come forward while suppressing others. People then separated themselves even further down into even smaller groups and different language variations.

Similar to selective breeding of dogs.

reply to post by jiggerj


In very dark-skinned people groups, individuals carry AABB genes and only produce dark-skinned offspring. In very light-skinned people groups, individuals carry aabb genes and only produce light-skinned offspring.
If a male and female from each group mate and produce a child, the combination of their AABB and aabb genes would give rise to a child who carries the AaBb genes for melanin and would be “middle brown” in skin shade. Now, if two people carrying the AaBb genes got married and reproduced, their children could have a wide rage of skin colors.

reply to post by evilmonkey


Ah the good old punnet square, not 100% accurate but it gets the information out simple.

ATS4dummies
OK, I guess I'll have to drop the bombshell.

Ready? Blacks ARE native to earth. All other races came from elsewhere and were genetically modified to acclimate to earth. That's why blacks have no neanderthal genes. Now you know.

That isn't how science lays it out. If all humans started with AABB genes then we wouldn't have any variation in skin color at all. We would all be AABB, or BLACK. Humans MUST have started with an AaBb combination x2 people which would be indicative of lets say, middle eastern people, otherwise people would all be one race with no chance of breeding alternate melanin combinations. It is my opinion that PEOPLE are native to earth.

Humans didn't become dark skinned, they became light skinned. They were originally dark skinned (or at least semi dark). The lighter skin didn't really become prevalent until Neanderthals & humans migrated out of Africa and lived in Europe and Asia for hundreds of thousands of years. One of the reasons for the dark skin is that higher melanin in the skin greatly reduces the risk of skin cancer. Living in Africa in an extremely hot and harsh environment, this skin protection was crucial to our survival. Lighter skin began with early hominids that lived in a cooler environment, while others migrated out and interbred with them. Less need for melanin, and they gradually got lighter.

It's a good argument to use against racists also. Just tell them their ancestors were black and watch the look on their face!

JohnPhoenix
reply to post by jiggerj

 

You are assuming evolution is at work here in Humans.. you say pre-humans and indicate these evolved into present day humans.

You simply cannot do that because evolution in humans from other non humans or pre-humans if not a fact based in science - it is only a theory one that has never been proven.

If you look at the worlds peoples and the climate they come from that tells the whole story. Hot ( equator) or cold ( north pole - Eskimos have dark skin) all those people have darker skin than humans who stayed in moderate climates. However there is also American Indians, many of which are as dark as black people. We (whites) are descended from Europeans who are a mixture of many moderate climates for the most part. I think the dominant genes for skin color play a factor here when races mix.

You are mixing things up a bit. The Eskimos have only lived in the arctic for 15,000 years give or take, same with native americans. They crossed the ice bridge to America during the last ice age They still have dark skin because not enough time has passed to cause a great change to their genome. Neanderthals & eventually humans lived outside of Africa for hundreds of thousands of years before the skin began to get lighter. You are talking 15,000 years out of the 200-300 thousand years of human evolution. And yeah evolution in humans from ancient ape is indeed proven by the 20+ species of hominids that fall in between, not to mention the genetic connections to Neanderthal and Denosivans.

11 White skin has evolved over time

It seems we were all black ones (consistent with evolutionary fact of first humans in Africa). White skin was a result of humans moving away from the equator. Also all skin, without coloring, would appear creamy white. Near-surface blood vessels add a blush of red. A yellow pigment also tints the canvas. Lastly, sepia-toned melanin, created in response to ultraviolet rays, appears black in large amounts. These four hues mix in different proportions to create the skin colors of all the peoples of Earth.


amazingbeautifulworld.com...

#11

reply to post by jiggerj


When the hair covering our ancestors bodies became thinner and shorter, our skin was exposed to the sun. As we originated in Africa, darker skin pigment was selected for. This is because dark skin pigment decreases UV absorption from the sun and therefore protects against DNA damage. As Africa is in the equatorial region, where the suns heat is most felt, this makes sense. When migration our of Africa occurred (over an extremely long period of time), the suns heat was obviously not as great. As some UV absorption is good, lighter skin was selected for, as dark skin in low light climates caused vitamin D deficiency as less vitamin D is able to be synthesized. As vitamin D helps with immunity, those with lighter skin would have a better survival chance, and would therefore pass on their genes as they lived long enough to reproduce. Ones with darker skin would have had poor immunity and would have died before they produced offspring, so only a small amount of dark skinned genes would be passed on in the regions where less sunlight is received.