Sorry again to all. I had some problems with my internet again so could not respond.
Most of my response to spoonist have already been brilliantly done by Big T in his last 2 posts so I will just mostly add and emphasize some things.
To be clear: what I referred to was the “out-of-Africa” theory of human migrations. It is the one which is most widely accepted by the field. In that theory it is east Africans mainly from the horn that populate the Nile valley and the red sea region, and then from that population some spread from that out over the globe. This is why Keita talks about a greater diversity within Africa than without. This since the out-of-Africa populations comes generally from a more limited genepool ie in the main horners.
So since the Americas, euroland, asia and Australian populations all comes from the same more limited genepool, then the potential for all of that we see around the globe comes from that genepool, which correspond to east Africa and the African horn in special. (With the exception for Svante Pääbo's research).
First off, let me emphasize 2 things: i. 'NonAfricans is a subset of East African/Horn African
diversity which is itself a subset of larger African diversity'. ii. 'NonAfricans derive from East
Having said that I want t also add that just as those Africans moved outside Africa, some move within Africa. For instance, L3 and M1 is distributed in parts of Africa with L3 in every region of Africa similar to L2 I think in terms of distribution(although not in frequency). A clade that demonstrates this clearly is E- which descends from the East African CT(parts of which went with current nonAfricans) and whose sub-clades are 'African specific',esp PN2 which originated in East Africa into 2: V33/V100(which divides into West Africa specific M2 and the East African Em329) and E-M215/M35(which is more East African and north African specific)-all these happening within the last 25,000/20000 yrs. This PN2 defines about 73% of all African Y-chromosome variation and more 85% of West Africa. Similarly, some of the clades rare/absent in nonAfricans who left and common with other Africans like L2(which is quite frequent almost as L3 in many East Africans), L1 and L0 also is part of East African genepool and it was this 'fuller' genepool that came to Nile Valley from the East Africa.
I Went through all these to show that unlike what Zentei was trying to show(Egyptian and Nubian 'Blacks' being distinct from other 'Black Africans') some of those clades common in East Africans/Horners are also distributed across Africans and some of then clades in other Africans are paart of East/Horn African genepool; and also that the East African genepool is 'fuller' than what you implied above.
So any claim that the population from that same genepool over the wide geographical regions in the sahara, the atlas, the magreb, the tibesti, the bab-el-mandeb and the nile delta etc, would not be diverse - simply contradicts Keita and the other sources used in this topic.
Apart to the 'fuller' genepool described above for East African/Horn African pool, a very important component of the genepool of the the areas you just mentioned(esp the critical Sahara) is the
Nilo-Saharan gene pool(both of whom are African).
But really the funny part of the above statement is your apparently linking 'genes' with skin tone cos that was what Big T was talking about.
Why wouldn’t I link genes, ie DNA, to skintone? Most of our potential skintone range lies in our genes. Exemplified by albinism, freckles, etc.
See this forensic study as specific evidence of genes vs skintone:http://onlinelibrary.wiley.com/doi/10.1 ... 43C.d04t01
Why would that obvious link be funny to you?
The section from that study on genes was talking about section of the genes that are responsible for skin colour common for all humans(as 'modified' by a persons adaptation history) just as some gene section are responsible for height,size etc but what I thought what you were trying to do was link specific clades to skin colour cos that will be wrong.
There are very dark-skinned and light skinned people with E,R,B,T,K etc clades. One's mtDNA, Y-
chromosme and overall autosomal DNA has nothing to do with skin colour except for the likelihood that ,if the clade is from a region that selects for darker skin and the population is still in that region or that a significant number of people left that region to another, then they can be dark-skinned- but any attempt to link these clades DIRECTLY to skin colour wil be funny
'Afroasiatic genes'(what the hell does this mean anyway?)
My bad, I shouldn’t have used that. It comes from the discussion on the “Afroasiatic Urheimat” where some haplogroups are used to make an argument for where the different branches of Afroasiatic languages originate. I think that it might have originated from Frank Yurco if he is familiar to you? I assumed that people discussing this would be familiar with Ehret’s and Keita’s work from 2004, or Cruciani et al from 2010 where this concept is discussed and used. But I used it out of context, so I agree that it didn’t necessarily make sense if you have not read those studies thoroughly enough
Okay aright. Were you meaning to write about clades like E-M35 that is common to Afroasiatic speakers as Keita and Ehret said? Anyways the correction noted.
Easy enough mistakes to make. You are conflating two things that overlap but do not necessarily correlate and you are missing the timescales involved. It has been repeated a couple of times in this topic though, so you might recognize it with this summary:
1) Skin tone is an adaptation vs UV radiation.http://www.bgsu.edu/departments/chem/fa ... r_2000.pdf
If you can’t be bothered to read through Jablonski’s excellent paper above then see either the Ted talk from upthread.http://www.ted.com/talks/nina_jablonski ... color.html
or read a blog summary from here.http://www.science20.com/the_evilutiona ... _the_world
from that blog comes this great pic, it is really telling:
2) Limb proportion is an adaptation vs climate, ie temperature and humidity. This is Allen's rule with the complimentary Bergman’s rule.http://www.ncbi.nlm.nih.gov/pubmed/9712477http://www.ispub.com/journal/the-intern ... ation.html
For the original see this really funny find of the original from the turn of the former century: http://libertarian-labyrinth.org/archiv ... of_Species
Now skin tone and limb proportions usually overlap but do not necessarily correlate. For example, the majority of Australia is below the Tropic of Capricorn but the aborigines of Australia are really dark skinned, regardless of the region of Australia that they come from. That is because the UV average is very high in Australia.
Modern UV map, note that it is not necessarily the same as 10kBP.http://www.soda-is.com/maps/world_uv_ab.png
Compare that to a modern climate maphttp://en.wikipedia.org/wiki/File:Koppen_World_Map.png
Please note that if you have lots of coverage vs the UV radiation like heavy foliage or staying mostly indoors, this will also affect this adaptation over time.
Which leads me to the issue of time scales, this means that population’s that migrate will over time adapt to their new environment. For example the Khoisan is theorized as having migrated very early into the southern tip of the African continent and thus adapted by becoming lighter and shorter than their closest African haplogroup relatives. What this means for the Saharan wet period is that we know that modern humans lived as early as 60k years ago in north Africa, probably earlier.http://archaeology.about.com/od/aterms/qt/aterian.htm
Thanks for the lecture(am particularly grateful for giving me a way to download the important Jablonski study) but there is nothing in that study or her TED lecture that opposes what we have said here- we knew and have said all along that skin colour is an adaptation to intense sunlight(you have rightly emphasized UV radiation) and does not have anything to do with 'race'. On the maps: if you look at the NAsA 7 Uv map at 3.20 in TED video, there is a correlation bw higher UV region and the tropics(as expected since as she explained at the tropics the sunlight is direct and the UV rays are more intense compared to northern latitudes)-esp in Africa. So by ecological principle, a tropical adapted populations will be dark-skinned precisely cos they need to protect themselves against UV radiation. So, again let me say again that tropical adapted populations in Africa who have been long term residents of the tropics would also have dark-skin cos of high UV associated with the tropics(except you are saying that a non-dark population would have been able to stand the UV of the tropics, if so name plz give examples) and the question stands: provide an eg that defiles this.
Ps: A part of Australia is tropical and Aborigines are tropical adapted so some of their ancestors must have migrated from such areas even if other areas also have high UV radiation.
we can also follow the industries slowly replacing each other, so aterian>Iberomaurusian>Capsian. So its not like they disappear for a while like they do in the sahara and levant when the climate changes. For me that is reason enough to assume that north Africans would adapt to the change in UV radiation even without any population input from other regions. See the Keita lecture for a 10k ballpark of such adaptation. Then from the lovely Wilma
, who really should spend less time digging in the sand and more time writing, we know that the wet sahara was populated from all directions and not just one and that hunter gatherer people moved around a lot, hence the non-permanent-settlements thingie.
Take a wild guess what I’m hinting for? Yupp, diversity – complexity – uncertainty, etc.
With that sort of timescales and vast geography one can’t be as assertive as some people driven by emotional arguments want. We have to put in the caveats and distrust the truisms, just like Keita does in his studies and in the lecture that this is all about according to the OP.
Okay now you are making a potentially believable point, so lets consider it: those people from coastal North Africa who would have gone into the Sahara would have certainly been a minority culturally and biologically there. Those people that entered the Nile Valley from the Sahara had biological affinities to other Africans to the south(not those coastal NW Africans), were tropically/supertropically adapted like other Africans to the south(unlike those people from coastal NW Africa that had intermediate proportions) and their culture(parts of the Saharo-Sudanese complex whose members were mostly related to the Nilo-Saharans) was not related to Iberomaurasian or Capsian.
So while I can except that like in the case of the Near East small groups of these coastal NW Africans MAY have been part of the Sahara and from there to the Nile Valley, they do not constituent a major part of the peopling of the Nile Valley.
I dont understand why people dont get it? See, Africa is like divided geographically into 2 trends climatically: a tropical forested and savanna centre and deserts on its 2 sides(Saharan and Namib Deserts). Then at both tips after these deserts are two sub-tropical environments('coastal' North Africa including most of Egyptian Nile and 'coastal' south African tips where they even have winters).
Why people like me don’t ‘get’ things like the sentences above is because that misses the time scale. Nope, at that time those divisions you talk about wasn’t really there. We are talking about the Neolithic subpluvial, leading into the modern era.
Check out this map.http://www.palgrave.com/history/shillin ... Map2.1.jpg
Then check out figure 11.2 on p228 in this book (11.1 is very interesting as well but not in this context)http://books.google.se/books?hl=sv&id=T ... 22&f=false
Those are the timescales and the changes in climate that we are talking about.
For a really interesting breaking thing from national geographic check this out in conte
Sponist I was referring mainly to the tropical/subtropical divisions and they have not changed(it is not same thing as the deserts that whether it was wet or not were always part of the tropics).
Recall, we know that by ecologically principle, a tropically adapted human population would be dark skin
I don’t think that “ecological principles” means what you think it means. See my argument above, or even better do read Jablonski above, or at least watch the Ted thingie.
By Ecological Principle, a tropically adapted population would also be dark-skinned cos a tropical environment also has higher UV levels so they MUST have dark skin in order to defend themselves aginst the UV coming from direct rays from tropical rays. ther is nothing in that TED video or the study that negates this. Stop palying games Spoonist or give examples that defiled this.
I will continue the response late on.