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Tsakhur
04-02-2016, 08:27 AM
What is the origin of R1b found in West Central Africa among Cameroonian and Chadic populations?

I found it very interesting that R1b also exist in high frequencies in Sub-Saharan Africa among these ethnic groups!

Are all R1b of Eurasian origin including the Cameroonian and Chadic ones?

Does this mean that many Cameroonian and Chadic populations have origins from Eurasia? If I am wrong, please correct me.

Thank you very much!: :D

VinceT
04-02-2016, 03:04 PM
They are R-V88, having migrated from central Eurasia around 10,000 years ago (by current estimates), returning to the Arabian peninsula and westward into northern Africa, and then northward across the Mediterranean Sea via the Gibraltar Straight (which may have been a land bridge at the time) into Iberia, intermingling with local populations along the way.

R-V88 descends from R-M415, who originated somewhere in central Eurasia within a few thousand years after the end of the Last Glacial Maximum.

http://www.ncbi.nlm.nih.gov/pubmed/11910562
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2987365/


Just to clarify, a Y-chromosome ancestor represents only one ancestral line out of many thousands.

Silesian
04-02-2016, 03:50 PM
ITA [IT-CA]is for-Cagliari Sardinia Has both -/+R-Y777710,000YBP+/-
NGA [NG-KN]is for Nigeria-Kano +R-Y18458
SAU is for Saudi Arabia R-FGC20973*
https://www.yfull.com/tree/R-V88/

can't_lurk_no_mo'
04-02-2016, 03:50 PM
According to Maciamo on Eupedia, V88 probably sprung from Northern Mesopotamia among the first people to domesticate cattle. People bearing this haplogroup then headed south and then west to Egypt, then spread in a pastoral economy from there, west across North Africa and south along the Nile until they found greener pastures.

8569

http://cache.eupedia.com/images/content/R1b-migration-map.jpg


http://cdn.eupedia.com/images/content/Haplogroup_R1b_World.png

vettor
04-02-2016, 05:17 PM
What is the origin of R1b found in West Central Africa among Cameroonian and Chadic populations?

I found it very interesting that R1b also exist in high frequencies in Sub-Saharan Africa among these ethnic groups!

Are all R1b of Eurasian origin including the Cameroonian and Chadic ones?

Does this mean that many Cameroonian and Chadic populations have origins from Eurasia? If I am wrong, please correct me.

Thank you very much!: :D

this paper would be of interest to you

https://www.academia.edu/3642572/Unraveling_the_Prehistoric_Ancestry_of_the_present-day_Inhabitants_of_Northeast_Africa._An_Archaeogen etic_Approach_to_Neolithisation

it states R1b-V88 entered africa via Egypt and moved south along the nile and eventually crossing over to west africa

NRY haplogroups R1b1c-V88 and T yield relevant information. R1b1c-V88 is interpreted byCruciani
et al (2002; 2010) as trans-Saharan pastoralists wandering toward the Chad Basin and the region of present-day Cameroon with a coalescence age between 9.2 and 5.6 kya.

Rethel
04-02-2016, 11:52 PM
They are R-V88, having migrated from central Eurasia around 10,000 years ago (by current estimates),

This is estimate for mutation - probably to high.

Dating migration at that time is pure science fiction, especially, that
the oldest known examples have half of that age and are from Spain.

Through Internet is cycling a map with 15.000 years.
It is not worthy a broken penny as well of course.

VinceT
04-03-2016, 01:22 AM
This is estimate for mutation - probably to high.

Dating migration at that time is pure science fiction, especially, that
the oldest known examples have half of that age and are from Spain.

Through Internet is cycling a map with 15.000 years.
It is not worthy a broken penny as well of course.

Is it?

The spread and distribution of R-V88 across northern Africa fits in with the idea of a "Green Sahara", which was actually a thing during the 7th millennium BCE up to about the 4th or 3rd millennium BCE. (Neolithic Subpluvial (https://en.wikipedia.org/wiki/Neolithic_Subpluvial)). Subsequent desertification pushed those peoples both south and north.

The Iberian Els Trocs sample [I0410/Troc 3 from Haak et al (2015) and Mathieson et al (2015)], was dated to 5178-5066 BCE, was also found to be PF6376+, which is one of the R1b-V88 equivalent SNPs. So we're looking at 7,200 years ago at least, and probably more.

Xuipa
04-03-2016, 03:42 PM
maybe wait until the bronze age study comes out before you start believing in all those other theories.... I mean they don't have 3500 years ago (bronze age collapse ) figured out yet in anyway .. yet many throw around older dates that they don't have a right to theorize about .

smal
04-03-2016, 04:38 PM
The Iberian Els Trocs sample [I0410/Troc 3 from Haak et al (2015) and Mathieson et al (2015)], was dated to 5178-5066 BCE, was also found to be PF6376+, which is one of the R1b-V88 equivalent SNPs. So we're looking at 7,200 years ago at least, and probably more.

1. The Iberian Els Trocs sample belongs to R-V88>Y7777 (xV35 xY8447) branch:


I0410, Els Trocs, Iberia_EN, 5295-5066 calBCE

V88 eq:
FGC20972/Y8457+
FGC21012/V2219+
PF6291+
PF6292+
PF6309+
PF6335+
PF6341+
PF6343+
PF6344+
PF6376+
BY426/Z5044+
Y:9513046 (C/T)+

V88 > FGC21034/SK2063/V2197, Y7777 eq:
FGC20984/YFC086522+
FGC21018/Y8460+
FGC21029/Y8453+
FGC21063/Y7784+
Y:6614515 (T/A)+
Z29595+

V88 > FGC21034/SK2063/V2197, Y7777 >V35 eq:
SK2068-
V35-
Z30236-
Z30246-
Z30252-
Z30256-
Z30264-
Z30275-
Y:22512713 (A/T)-
Y:22270223 (G/A)-
Y:22271110 (C/T)-

V88 > FGC21034/SK2063/V2197, Y7777 > Y8447 eq:
FGC20970/Y8447-

V88 > FGC21034/SK2063/V2197, Y7777 > Y8447 > Y7771 eq:
FGC20558-
SK2071/V1944-
Y:22263077 (A/G)-
Y8437-
Y8438-
Y8439-
Y8440-

V88 > FGC21034/SK2063/V2197, Y7777 > Y8447> FGC20969 eq:
FGC20969-
FGC20981-
FGC20983-

I0122, Khvalynsk II, Volga River, Samara [5200-4000 BCE] (http://www.anthrogenica.com/showthread.php?5875-230-ancient-Eurasians-data-analysis-(Mathieson-Reich-Haak-)&p=123365&viewfull=1#post123365)

2. YFull underestimate an age of the split between R-M18, R-Y7777, and R-V88* (Saxton's line) because they have in their tree only 1 R-M18 sample with many gaps in a sequence.

3. We do not have an information about a distribution of the R-V88 subclades. However, from STR data we can assume that a majority of samples from Arabian peninsula or Africa belong to several recent subclades of R-Y8447.

Rethel
04-03-2016, 09:11 PM
Is it?

The spread and distribution of R-V88 across northern Africa fits in with the idea of a "Green Sahara", which was actually a thing during the 7th millennium BCE up to about the 4th or 3rd millennium BCE. (Neolithic Subpluvial (https://en.wikipedia.org/wiki/Neolithic_Subpluvial)). Subsequent desertification pushed those peoples both south and north.

The Iberian Els Trocs sample [I0410/Troc 3 from Haak et al (2015) and Mathieson et al (2015)], was dated to 5178-5066 BCE, was also found to be PF6376+, which is one of the R1b-V88 equivalent SNPs. So we're looking at 7,200 years ago at least, and probably more.

There is no proof for that. Only fantastical assumption.
Some dating of african V88 give even possibility, that
this subclade went into Africa 1000-1500 years ago,
as well as 4000-5000 - this is some reasonable dates.

10 or 15 thousand it is total fiction.

There is no so much as it could seems from the map of R1b.
And it must be remeberd that lets say 4000 ya subsaharian
Africa had very small population, in which R1b was no more
than 2-3%... very small tribe could do that, and there was
no need for dozens of thousands years. Especially, that yet
couple of thousands of yeas V88 was in Spain, and still is
scattered across the Europe.

VinceT
04-03-2016, 10:24 PM
I quite agree, presence of R1b-V88 in Africa, Arabia, or Spain 15,000 years ago is unlikely. A range of 7,500 to 10,000 years ago is much more likely. So far, finding "proof" of R-V88 from ancient remains in Arabia and Africa has demonstrated difficult, as ancient DNA doesn't handle heat very well. So, yes, assumptions have been made, but the presence of humans in the Sahara 10,000 years ago is by no means as "fantastical" as you insist.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2515196/

Agamemnon
04-04-2016, 01:19 AM
The main African marker under R1b-V88 is V69, which is also found in the Arabian peninsula. It's a sub-branch of Y7771 which, in turn, is a branch of Y8447. According to YFull V69's TMRCA is ~4400 years old, a more realistic estimate would be 5000 yBP, Y7771's TMRCA is ~5000 years old while Y8447's TMRCA is ~6900 years old (again according to YFull). Some enthusiasts insinuate that R1b-V69's association with Chadic-speaking groups tilts the odds in favour of a Near Eastern homeland for Proto-Afroasiatic. I think this is a form of intellectual laziness, my current understanding of AA phylogeny strongly suggests that Chadic was one of the very last branches to break free from the Afroasiatic language bundle, shortly before Egyptian (with which it might even form a common node). ~7400 years BP is rather convincing, at least that's the time frame I'd expect for Pre-Proto-Chadic, by that time Y8447 had probably made it to North Africa and joined the earliest Chadic-speaking groups in the Eastern Sahara (which was much more lush and moist back then). The break up of Proto-Chadic proper could be tied to the 5.9 kiloyear event and the subsequent aridification of North Africa, that would fit nicely with what we know about other branches of AA, but more work needs to be done on Proto-Chadic to gauge the validity of this diachronic model.

Tsakhur
04-04-2016, 05:54 AM
Thank you very much everyone for your replies! What I also wonder is autosomally do Chadic, Cameroonian populations have some Eurasian ancestry as well and how much?

Tsakhur
04-04-2016, 05:57 AM
The main African marker under R1b-V88 is V69, which is also found in the Arabian peninsula. It's a sub-branch of Y7771 which, in turn, is a branch of Y8447. According to YFull V69's TMRCA is ~4400 years old, a more realistic estimate would be 5000 yBP, Y7771's TMRCA is ~5000 years old while Y8447's TMRCA is ~6900 years old (again according to YFull). Some enthusiasts insinuate that R1b-V69's association with Chadic-speaking groups tilts the odds in favour of a Near Eastern homeland for Proto-Afroasiatic. I think this is a form of intellectual laziness, my current understanding of AA phylogeny strongly suggests that Chadic was one of the very last branches to break free from the Afroasiatic language bundle, shortly before Egyptian (with which it might even form a common node). ~7400 years BP is rather convincing, at least that's the time frame I'd expect for Pre-Proto-Chadic, by that time Y8447 had probably made it to North Africa and joined the earliest Chadic-speaking groups in the Eastern Sahara (which was much more lush and moist back then). The break up of Proto-Chadic proper could be tied to the 5.9 kiloyear event and the subsequent aridification of North Africa, that would fit nicely with what we know about other branches of AA, but more work needs to be done on Proto-Chadic to gauge the validity of this diachronic model.

Thank you very much for such a detailed explanation! I appreciated it! :) What I wonder is autosomally do Chadic, Cameroonian populations have some Eurasian ancestry as well and how much?

Heber
03-15-2017, 06:32 PM
Humans as Agents in the Termination of the African Humid Period

David K. Wright*
Department of Archaeology and Art History, Seoul National University, Seoul, South Korea
There is great uncertainty over the timing and magnitude of the termination of the African Humid Period (AHP). Spanning from the early to middle Holocene, the AHP was a period of enhanced moisture over most of northern and eastern Africa. However, beginning 8000 years ago the moisture balance shifted due to changing orbital precession and vegetation feedbacks. Some proxy records indicate a rapid transition from wet to dry conditions, while others indicate a more gradual changeover. Heretofore, humans have been viewed as passive agents in the termination of the AHP, responding to changing climatic conditions by adopting animal husbandry and spreading an agricultural lifestyle across the African continent. This paper explores scenarios whereby humans could be viewed as active agents in landscape denudation. During the period when agriculture was adopted in northern Africa, the regions where it was occurring were at the precipice of ecological regime shifts. Pastoralism, in particular, is argued to enhance devegetation and regime shifts in unbalanced ecosystems. Threshold crossing events were documented in the historical records of New Zealand and western North America due to the introduction of livestock. In looking at temporally correlated archeological and paleoenvironmental records of northern Africa, similar landscape dynamics from the historical precedents are observed: reduction in net primary productivity, homogenization of the flora, transformation of the landscape into a shrub-dominated biozone, and increasing xerophylic vegetation overall. Although human agents are not seen as the only forces inducing regime change during the termination of the AHP, their potential role in inducing large-scale landscape change must be properly contextualized against other global occurrences of neolithization.

http://journal.frontiersin.org/article/10.3389/feart.2017.00004/full