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Gavros 1:22 Wed Feb 7
'First Briton' was...
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....blue eyed.
https://www.theguardian.com/science/2018/feb/07/first-modern-britons-dark-black-skin-cheddar-man-dna-analysis-reveals
Discuss.
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Replies - Newest Posts First ( Show In Chronological Order)
Dwight Van Mann
5:57 Mon Feb 26
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so science can supposedly tell us the skin tone of a man who died 10,000 years ago but it's inappropriate and unethical (according to advisers to the Home Office) to tell the difference between a bearded 35yr old Syrian from Pakistan and a 14yr old boy refugee?
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Willtell
5:43 Mon Feb 26
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OK Comma. Why do pedants drag everything through the wringer? I said corpse knowing full well that he is a 10,000 year old bag of bones because I saw the TV programme thanks.
The fact is that it is not written in stone accuracy that he was a blue eyed, wavy and dark haired black man. But if he was who really gives a shit either way? Only a racist would be bothered by skin colour and I'm not bothered....
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Swiss.
3:25 Mon Feb 26
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I see all the "I don't believe it!" racists like mlashed and Willtell are out in force.
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Thames Ironworks
1:48 Mon Feb 26
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He was a slave, stolen as a child and dragged to Somerset to dig caves and make cheese.
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,
1:05 Mon Feb 26
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Willtell 11.13, it is a 10,000 year old skeleton not corpse.
I was looking at it yesterday.
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gph
1:02 Mon Feb 26
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Science has a unity, because the same ways of arguing are used throughout.
So you can tell that scientist are full of shit because planes don't fly, cars don't go and the internet doesn't exist.
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Willtell
11:13 Mon Feb 26
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Does it really matter?
Scientists are invariably full of shit because no-one knows enough to call them out on it. So a 10,000 year old corpse might have had blue eyes, curly dark hair and a sun tan.
Perhaps he'd just returned from a holiday....
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HairyHammer
10:37 Sat Feb 24
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Roman or Greek ?
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Gavros
10:01 Sat Feb 24
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a Jew?
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gph
8:45 Fri Feb 23
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So, the direct evidence can only support the claim that this bloke was "most probably" dark-skinned.
But there's also the indirect evidence that this combination of genes is rare in present-day European populations, yet clearly not very disadvantageous elsewhere in the world, if at all.
If these genes didn't have an effect on skin colour, there must've been some other disadvantage to them in the particular circumstances of Europe at some point after this bloke was around, and this disadvantage must have persisted for some time.
If genes do nothing, evolution doesn't care (much) they're there.
DNA, per se, seems to be very cheap, as there are some very simple organisms with loads more genes than they appear to need.
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ironsofcanada
8:14 Fri Feb 23
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The whole article, I was running into a paywall on the regular net.
TL;DR
The researcher that did the study says this does not prove anything, the sample was degraded, research is developing etc. She says "It is his most probable profile, based on current research.” Other researchers say older models have been outright wrong in the past.
Ancient ‘dark-skinned’ Briton Cheddar Man find may not be true
A Briton who lived 10,000 years ago had dark brown skin and blue eyes. At least, that’s what dozens of news stories published this month – including our own – stated as fact. But one of the geneticists who performed the research says the conclusion is less certain, and according to others we are not even close to knowing the skin colour of any ancient human.
The skeleton of Cheddar Man was discovered in 1903 in a cave in south-east England where it had lain for 10,000 years.
Until a few weeks ago, he had always been depicted with pale skin. This makes some sense, given that people living at northern latitudes often have paler skins. The explanation may be that it allows more of the weak northerly sunlight into their skin, so they can make enough vitamin D. And it seems our species reached Europe 30,000 years before Cheddar Man lived, so his ancestors would have had plenty of time to evolve paler skins.
But the new DNA analysis suggests that Cheddar Man may have had dark skin. Most news stories said his skin was “dark to black”.
Giveaway genes
To show this, researchers including Susan Walsh at Indiana University–Purdue University Indianapolis read Cheddar Man’s DNA. Walsh had helped develop a model that attempts to predict someone’s eye, hair and skin pigmentation solely from their DNA, and the team applied this model to Cheddar Man.
The most recent version of the model was published in May 2017. It focuses on 36 spots in 16 genes, all linked to skin colour.
To test it, Walsh and her colleagues took genetic data from over 1400 people, mainly from Europe and the US but also some from Africa and Papua New Guinea. The team used part of the data to “train” their model on how skin colour and the 36 DNA markers are linked. They then used the rest of the data to test how well the model could predict skin colour from DNA alone. The model correctly identified who had “light” skin or “dark-black” skin, with a small margin of error.
When Walsh and her colleagues applied the model to Cheddar Man, they concluded his skin colour fell between “dark” and “dark to black”.
Not so sure
The research was first announced by press release, to coincide with the release of a TV documentary. It has now been posted to a preprint server.
Walsh stresses that the study doesn’t conclusively demonstrate Cheddar Man had dark to black skin. We cannot place such confidence in the DNA analysis, she says. For one thing, Cheddar Man’s DNA has degraded over the last 10,000 years.
“It’s not a simple statement of ‘this person was dark-skinned’,” says Walsh. “It is his most probable profile, based on current research.”
In fact, we are not ready to predict the skin colour of prehistoric people just from their genes, says Brenna Henn at Stony Brook University, New York. That’s because the genetics of skin pigmentation turn out to be more complex than thought.
Too many genes
In November 2017, Henn and her colleagues published a paper exploring the genetics of skin pigmentation in populations indigenous to southern Africa – where skin colour varies more than many people appreciate. Just weeks before, a group led by Sarah Tishkoff at the University of Pennsylvania in Philadelphia had published a paper on the genetics of skin pigmentation in people from eastern and southern Africa.
“The conclusions were really the same,” says Henn. “Known skin pigmentation genes, discovered primarily in East Asian and European populations, don’t explain the variation in skin pigmentation in African populations. The idea that there are really only about 15 genes underlying skin pigmentation isn’t correct.”
It now seems likely that many other genes affect skin colour. We don’t know how.
If we are still learning about the link between genes and skin pigmentation in living populations, we can’t yet predict the skin colour of prehistoric people, says Henn.
This debate may seem of little practical importance – although the idea that Cheddar Man was dark-skinned generated enormous public interest. However, we need to know the limitations of this sort of genetic technology.
Police could one day plug DNA from a crime scene into one of these models to determine what a suspect looks like. Walsh’s model might succeed at this in the US, says Henn, because it was trained on DNA from people with similar ancestry to North Americans. But it may well fail elsewhere.
Henn’s team has tested an older model that aimed to predict skin colour from DNA. When they put it to work among southern African populations, “it literally predicted that people with the darkest skins would have the lightest skin”
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mashed in maryland
7:51 Fri Feb 23
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https://www.newscientist.com/article/2161867-ancient-dark-skinned-briton-cheddar-man-find-may-not-be-true/amp/?__twitter_impression=true
Lol.
Didn't take long....
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gph
8:18 Wed Feb 21
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The UV absorbed by melanin doesn't go to manufacture vitamin D. It's absorbed before it can be used for that purpose. So the more melanin, the less UV is available for the manufacture of vitamin D.
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Swiss.
6:21 Wed Feb 21
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And the sun was younger and stronger then
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Swiss.
6:16 Wed Feb 21
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I mean I know more sun creates more menalin but a white face would be more useful in bright sun as it would reflect more but then get darker and less effective.
Bit arse around tit really
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Swiss.
6:13 Wed Feb 21
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gph
But black absorbs more than white so if there is less sun shouldn't we be more black?
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gph
4:25 Wed Feb 21
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It's the interaction between farming and the weak Sun that favours fair skin.
One on its own doesn't work.
Hence, black farmers in Africa, and black hunter-gatherers in Europe.
Of course, this leaves the Middle East unexplained. My guess is that some Europeans went back there, or that all-enveloping desert dress left too little skin exposed, or a combination. I expect more research will provide the answers
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Gavros
4:08 Wed Feb 21
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There is one curiosity of this farmers became white argument.
Unless you count aboriginies, all humans became farmers.
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gph
3:46 Wed Feb 21
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"When searching for a mate who offers the best chance of your own genes being passed on down the line, I seriously doubt that "Wow! Look at the diet on that!" was that popular a phrase."
So?
Obviously, it's the consequences of the diet that count.
Same with the skin. I seriously doubt people said "Wow! look at the vitamin D their skin pumps out!". Especially as they didn't have a clue what vitamin D was.
An agricultural lifestyle before metal implements would have meant more time out in the sun working - it's been fairly well established that early agricultural peoples spent more time working to provide themselves with food than did hunter-gatherers.
On average, switching to an agricultural lifestyle has so many immediate disadvantages - poorer diet, harder, longer and more boring work, that I imagine only lucky farmers stuck with it long enough to see the long-term advantage. Greater food security.
At that point, there being a lower chance of seeing your kids die would have become something pushing people towards farming.
All this is a simplification in at least one point - it's thought that there were many stopping points between being 100% hunter-gatherer and 90% farmer. For quite a long time, people were only primarily farmers.
Nevertheless, yes, there was a distinct advantage to having fair skin in regions where the Sun was weak.
But that was then, and it wasn't true before then, and it isn't true now.
It could become true again, if there was a collapse in civilisation involving terrible effects on the average diet, with no recovery for hundreds of years.
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Mike Oxsaw
3:25 Wed Feb 21
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Gavros 3:11 Wed Feb 21
And how is that proof? It's all a bit chicken & egg. It may have fuck all to do with the diet and everything to do with more just sitting around in caves chillin;'.
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