...
EgyptSearch Forums Post New Topic  New Poll  Post A Reply
my profile | directory login | register | search | faq | forum home

  next oldest topic   next newest topic
» EgyptSearch Forums » Egyptology » Were Africans more or less likely to survive major human bottlenecks?

 - UBBFriend: Email this page to someone!    
Author Topic: Were Africans more or less likely to survive major human bottlenecks?
Ase
Member
Member # 19740

Rate Member
Icon 1 posted      Profile for Ase     Send New Private Message       Edit/Delete Post   Reply With Quote 
Another question I've been asked: When historical bottleneck events (that nearly wiped humans out) happened, how many of the survivors lived in Africa?
Posts: 2508 | From: . | Registered: Nov 2011  |  IP: Logged | Report this post to a Moderator
Clyde Winters
Member
Member # 10129

Rate Member
Icon 1 posted      Profile for Clyde Winters   Author's Homepage     Send New Private Message       Edit/Delete Post   Reply With Quote 
The question is interesting but it can't be answered until scientist establish a date for any alleged bottleneck event(s). As you may know these bottlenecks are hypothetical. Thus a rendering of their effects would be speculative.

In addition, you would not look at historical events to garner the truth about these happenings. You would have to study archaeology.

But it would appear that such events occurred because we see successive populations, e.g., Australians replaced 60kya in Americas and Eurasia by Khoisan , the Khoisan replaced by Pygmies 25kya, Pygmies replaced by contemporary Sub-Saharan Africans 10kya.

--------------------
C. A. Winters

Posts: 13012 | From: Chicago | Registered: Jan 2006  |  IP: Logged | Report this post to a Moderator
Andromeda2025
Junior Member
Member # 22772

Rate Member
Icon 1 posted      Profile for Andromeda2025     Send New Private Message       Edit/Delete Post   Reply With Quote 
Africans were and always will be able to survive major human bottlenecks because of the African continent itself.
Posts: 165 | From: Miami Beach, Florida | Registered: Jun 2017  |  IP: Logged | Report this post to a Moderator
Djehuti
Member
Member # 6698

Rate Member
Icon 1 posted      Profile for Djehuti     Send New Private Message       Edit/Delete Post   Reply With Quote 
quote:
Originally posted by Oshun:

Another question I've been asked: When historical bottleneck events (that nearly wiped humans out) happened, how many of the survivors lived in Africa?

I don't think we'll ever know how many survived but we can get an idea of how much of the gene pool has survived from the DNA of living people and especially in comparison to remains of ancient people.

According to geneticists like Dr. Stephen Oppenhiemer Mitochondrial Eve and those members of her population (130-230 kya) in Africa were survivors of a previous bottle-neck event in form of a megadrought. Then about 100-75 kya which coincided with the initial OOA migration there was another megadrought.

Below is a map showing the known major population bottlenecks.

 -

Interestingly when it comes to Africa the Khoisan represent a once major population:

Living African group discovered to be the most populous humans over the last 150,000 years

New genetic research reveals that a small group of hunter-gatherers now living in Southern Africa once was so large that it comprised the majority of living humans during most of the past 150,000 years. Only during the last 22,000 years have the other African ethnicities, including the ones giving rise to Europeans and Asians, become vastly most numerous. Now the Khoisan (who sometimes call themselves Bushmen) number about 100,000 individuals, while the rest of humanity numbers 7 billion. Their lives and ways have remained unaltered for hundreds of generations, with only recent events endangering their hunter-gatherer lifestyles. The study's findings will be published in the journal Nature Communications on 4 December 2014.

http://science.psu.edu/news-and-events/2014-news/Miller12-2014

Khoisan hunter-gatherers have been the largest population throughout most of modern-human demographic history

The Khoisan people from Southern Africa maintained ancient lifestyles as hunter-gatherers or pastoralists up to modern times, though little else is known about their early history. Here we infer early demographic histories of modern humans using whole-genome sequences of five Khoisan individuals and one Bantu speaker. Comparison with a 420 K SNP data set from worldwide individuals demonstrates that two of the Khoisan genomes from the Ju/’hoansi population contain exclusive Khoisan ancestry. Coalescent analysis shows that the Khoisan and their ancestors have been the largest populations since their split with the non-Khoisan population ~100–150 kyr ago. In contrast, the ancestors of the non-Khoisan groups, including Bantu-speakers and non-Africans, experienced population declines after the split and lost more than half of their genetic diversity.

Paleoclimate records indicate that the precipitation in southern Africa increased ~80–100 kyr ago while west-central Africa became drier. We hypothesize that these climate differences might be related to the divergent-ancient histories among human populations.

Yet Khoisan populations have maintained the greatest nuclear-genetic diversity among all human populations3, 4, 5 and the most ancient Y-chromosome and mitochondrial DNA lineages6, 7, implying relatively larger effective population sizes for ancestral Khoisan populations.

http://www.nature.com/ncomms/2014/141204/ncomms6692/full/ncomms6692.html

--------------------
Mahirap gisingin ang nagtutulog-tulugan.

Posts: 26249 | From: Atlanta, Georgia, USA | Registered: Feb 2005  |  IP: Logged | Report this post to a Moderator
xyyman
Member
Member # 13597

Rate Member
Icon 1 posted      Profile for xyyman   Author's Homepage         Edit/Delete Post   Reply With Quote 
There wasn't any bottle as such. Other than IBD. Isolation by Distance.
-----

Contacts in the last 90,000 years over the Strait of Gibraltar evidenced by genetic analysis of wild boar (Sus scrofa)-Carmen Soria-Boix
Quotes:
Introduction
At present, Africa and Europe are in close proximity to each other geographically speaking,
and are by only 14 km separated through the Strait of Gibraltar. However, it is known that
major falls in sea level (~100 metres) related to glacial periods, and the consequent emergence
of islands, reduce this distance
to smaller marine barriers, less than 5 km each [1±3]. In this situation
the interaction between both sides of the strait seems possible despite it being a barrier
for some species [4±8].
Evidence of contacts across major marine distances is not new. Human dispersal across a
marine barrier 0.88 million years ago (MYA) has been proven in the Flores Island (Java)
[9,10]. During glacial periods, the Strait of Sicily would not have acted as a major geographical
Barrier
for some species [11,12]. On the Strait of Gibraltar, some documented cases are found
of movements of hominids and fauna across this permeable barrier [2,10,13±17]. For example,
the arrival of humans and vertebrate fauna to the Iberian Peninsula from Africa has been
recorded
at the sites of Orce (southeast Spain) as early as the Plio-Pleistocene boundary
[2,10,18].

The present study aims to elucidate contacts between Africa and the Iberian Peninsula
across the Strait of Gibraltar
by considering the genetic similarity of the wild boar populations
on both sides of the strait.

As for the causes of movements, if they took place approximately from 90,000 ONWARD, it is
difficult to know if contacts were made by natural colonisations, by human action, or by a
combination of both without having further data [48,49]. This is due to several events occurring
at the same time. In addition, it would appear that the South region of the Iberian Peninsula
and North Africa form part of a refugial subcentre denominated Atlanto-Mediterranean,
from which species could have recolonised areas in North of Europe at the beginning of the
post-glacial periods the
[5,11,17].

Therefore, we suggest that the Strait of Gibraltar acted as a bridge for wild boar (S. scrofa) to
disperse in the Late Pleistocene. In this case, the dispersion of specimens accompanied by a
strong gene flow would have been occurred from at least 90,000 years onward. Genetic analyses,
the history of S. scrofa, and the fact that the Last Glacial period finished 11,700 years ago,
all suggest natural dispersion, but we cannot rule out the contact by human action.

--------------------
Without data you are just another person with an opinion - Deming

Posts: 12143 | From: When you have eliminated the impossible, whatever remains, however improbable | Registered: Jun 2007  |  IP: Logged | Report this post to a Moderator
Djehuti
Member
Member # 6698

Rate Member
Icon 1 posted      Profile for Djehuti     Send New Private Message       Edit/Delete Post   Reply With Quote 
^ You just cited a source about one part of Africa-- the Maghreb. Also the source itself implies a bottleneck in the form a refugium. There also remains the fact that virtually all people in the Maghreb today carry African lineages that are relatively recent (post-neolithic/historical) due to founder effect. What happened to the carriers of paleolithic lineages?
Posts: 26249 | From: Atlanta, Georgia, USA | Registered: Feb 2005  |  IP: Logged | Report this post to a Moderator
xyyman
Member
Member # 13597

Rate Member
Icon 1 posted      Profile for xyyman   Author's Homepage         Edit/Delete Post   Reply With Quote 
quote:
Originally posted by Djehuti:
^ ... There also remains the FACT???? that virtually all???? people in the Maghreb today carry*** African lineages*** that are relatively recent (post-neolithic/historical) due to founder effect. What happened to the carriers of paleolithic lineages?

I am not sure WT..you said there. "African lineage that is recent". What the ...is a recent African lineage? That is the type of jibberish that comes from the mouth of Sweetness

I know you are a mole. Haven't they trained you well or are you that obtuse?


----
Females in the Maghreb
HV=40,000years old
V=35,000
H=25,000
U6=35,000
U2=25,000
X=35,000
L=100,000 or more

Males
E1b1b=25,000
R1b-V88=17,000
J1=30,000
---


So WTF are you talking about "recent" or Neolithic? You just get under my fugcking skin with your subtle double talk!!!! Come out the closet and admit you are a Euronut mole. Not an ounce of objectivity

--------------------
Without data you are just another person with an opinion - Deming

Posts: 12143 | From: When you have eliminated the impossible, whatever remains, however improbable | Registered: Jun 2007  |  IP: Logged | Report this post to a Moderator
xyyman
Member
Member # 13597

Rate Member
Icon 1 posted      Profile for xyyman   Author's Homepage         Edit/Delete Post   Reply With Quote 
To the newbies. My point is the mtDNA lineage in North Africa go back to the late Paleolithic. One one aDNA study exits in all of Africa using skeleton greater than 20,000years. Kefi et al = Morocco. The lineages are U, H and L IIRC. The same lineage that exist in North Africa today. This clown just get riled up with his lies. Lioness lies, but we all know his(Lioness) role here. But when this clown gets on here and pretend to be something he is not and try to pull the covers over our eyes. .....grrrrr

--------------------
Without data you are just another person with an opinion - Deming

Posts: 12143 | From: When you have eliminated the impossible, whatever remains, however improbable | Registered: Jun 2007  |  IP: Logged | Report this post to a Moderator
Djehuti
Member
Member # 6698

Rate Member
Icon 1 posted      Profile for Djehuti     Send New Private Message       Edit/Delete Post   Reply With Quote 
^ I was referring to the paternal lineages. The vast majority of Maghrebis carry subclades of E1b1b, namely subclades of E-M81. Yes, basal E1b1b is about 25,000 years old but Maghrebi men don't carry that so I don't know if you're being dishonest or just ignorant. I'm assuming the latter. R1b-V88 probably didn't originate in Africa but most certainly not the Maghreb and neither did J1. So please calm down.

--------------------
Mahirap gisingin ang nagtutulog-tulugan.

Posts: 26249 | From: Atlanta, Georgia, USA | Registered: Feb 2005  |  IP: Logged | Report this post to a Moderator
xyyman
Member
Member # 13597

Rate Member
Icon 1 posted      Profile for xyyman   Author's Homepage         Edit/Delete Post   Reply With Quote 
Fool. The Maghreb has been occupied >90,000years by HUMANS.

So as you said E-78 and E-81. What are the ages?

"Haplogroup E-V68, also known as E1b1b1a, is a major human Y-chromosome DNA haplogroup found in North Africa, the Horn of Africa, Western Asia and Europe"


Wait! It was a male ONLY migration from East Africa to the Maghreb. Where they admixed with European women who migrated from Europe, ALSO ALONE, no European men, lol!


You a such a Putz! Mole!

--------------------
Without data you are just another person with an opinion - Deming

Posts: 12143 | From: When you have eliminated the impossible, whatever remains, however improbable | Registered: Jun 2007  |  IP: Logged | Report this post to a Moderator
Clyde Winters
Member
Member # 10129

Rate Member
Icon 1 posted      Profile for Clyde Winters   Author's Homepage     Send New Private Message       Edit/Delete Post   Reply With Quote 
 -

R1-V88 is of African origin. Anyone who claims otherwise, should present the archaeological evidence of a European back Migration. The archaeological and linguistic evidence supports an African introduction of R1, into Anatolia, and the rest of Eurasia.

"Today the Black Variety is referred too, in the archaeogenetics literature as Sub-Saharan Africans.

Between 3200-2900 BC, African culture and people began to migrate into Iberia and introduced
megaliths and the Bell Beaker culture (Lahovary, 1963). Spanish researchers accepted the reality that the Iberia Peninsula owed the major parts of Neolithic Iberia to African immigrants (Lahovary, 1963; Macwhite, 1947).

MacWhite (1947) claims there was a close relationship between Iberia and Britain. These researchers admit that Portugal and Brittany were settled by Megalithic Africans who founded respectively the Mugem and Teviec sepultures (Lahovary, 1963; MacWhite, 1947).

Olalde et al., (2017) discuss the spread of Bell Beaker culture across Europe 27 kya. These researchers found limited genetic affinity between individuals from Iberian and central Europeans. Olalde et al.,(2017) concludes that migration probably played an insignificant mechanism in the spread of R1 within the two areas.


The Neolithic British farmers were genetically similar to Neolithic Iberians dating between 3900–1200 BCE (Olalde et al., 2017; MacWhite, 1947; Mathieson et al., 2017). The British farmers were replaced by farmers of the Beaker culture (Olalde et al., 2017). Eighty-four percent of the Beaker Bell Steppe migrants carried R1b (Olalde et al., 2017).

Bell Beaker appeared in Iberia around 2700 BCE (Cardoso, 2014; Olalde et al., 2017; Müller and van Willigen, 2001). It is interesting to note that while most people in the Iberian Beaker complex carried the G2 and I2a2 haplogroups (Olalde et al., 2017; Mathieson et al., 2017). Iberians during this period also carried R-V88 (Kivisild, 2017; Mathieson et al., 2017)."

See: http://www.cibtech.org/J-LIFE-SCIENCES/PUBLICATIONS/2017/VOL-7-NO-2/04-JLS-004-WINTERS-A-EURASIA.pdf

.

--------------------
C. A. Winters

Posts: 13012 | From: Chicago | Registered: Jan 2006  |  IP: Logged | Report this post to a Moderator
Djehuti
Member
Member # 6698

Rate Member
Icon 1 posted      Profile for Djehuti     Send New Private Message       Edit/Delete Post   Reply With Quote 
quote:
Originally posted by xyyman:

Fool. The Maghreb has been occupied 90,000years by HUMANS.

YOU're the fool. By "90,000 years" I assume you are referring to the Aterians. We have no DNA from the Aterians and NON of the clades of present day Maghrebis even approaches the Aterian age.

quote:
So as you said E-78 and E-81. What are the ages?
Maghrebi males carry E-M81 and downstream lineages at that. Basal E-M81* arose around 14,000 years ago but basal M-81 is rare in the Maghreb

quote:
"Haplogroup E-V68, also known as E1b1b1a, is a major human Y-chromosome DNA haplogroup found in North Africa, the Horn of Africa, Western Asia and Europe"
But what does E-V68 have to do with the Maghreb which is derived from E-V257??

quote:
Wait! It was a male ONLY migration from East Africa to the Maghreb. Where they admixed with European women who migrated from Europe, ALSO ALONE, no European men, lol!
LOL Where did I say that only sex migrated??

quote:
You a such a Putz! Mole!
You need to say the above next time you look in the mirror, you deranged clown! [Big Grin]
-------------------------
Without a proper assessment of data you are just another ignoramus with a false opinion

Posts: 26249 | From: Atlanta, Georgia, USA | Registered: Feb 2005  |  IP: Logged | Report this post to a Moderator
xyyman
Member
Member # 13597

Rate Member
Icon 1 posted      Profile for xyyman   Author's Homepage         Edit/Delete Post   Reply With Quote 
:rolleyes: :rolleyes:

Aterians arent humans?

"Fool. The Maghreb has been occupied 90,000years by HUMANS.
YOU're the fool. By "90,000 years" I assume you are referring to the Aterians. We have no DNA from the Aterians and NON of the clades of present day Maghrebis even approaches the Aterian age."

"So as you said E-78 and E-81. What are the ages?
Maghrebi males carry E-M81 and downstream lineages at that. Basal E-M81* arose around 14,000 years ago but basal M-81 is rare in the Maghreb
"
:rolleyes: :rolleyes:

--------------------
Without data you are just another person with an opinion - Deming

Posts: 12143 | From: When you have eliminated the impossible, whatever remains, however improbable | Registered: Jun 2007  |  IP: Logged | Report this post to a Moderator
Swenet
Member
Member # 17303

Member Rated:
4
Icon 1 posted      Profile for Swenet     Send New Private Message       Edit/Delete Post   Reply With Quote 
You got owned gramps [Wink]

Aterians and contemporary North Africans (e.g. Nubian Complex people) have a very ancient origin in Sub-Saharan Africa. So ancient that we still can't conclusively pin-point directly ancestral cultures in Sub-Saharan Africa. The African ancestry that is specific to North Africa (i.e. Berber ancestry that's not the result of recent migration from SSA) is mainly derived from newcomers (e.g. E-M81, L3f), as DJ correctly pointed out. Aterians have nothing to do with this based on the fact that you have to go back too far to fit Aterians on the human lineage. For instance, YDNA A00 might be Aterian related and it connects to our human tree >200ky ago (which is way too ancient be the source of most Berber ancestry).

Surely, fossils like Border Cave are closer related to us than Aterians are. And our ancestors couldn't have been in two places at once, this early. Since Border Cave is in South Africa, our ancestors would have been closer to South Africa, which is geographically very distant from whatever was going on in North Africa at the time.

Posts: 8785 | From: Discovery Channel's Mythbusters | Registered: Dec 2009  |  IP: Logged | Report this post to a Moderator
   

Quick Reply
Message:

HTML is not enabled.
UBB Code™ is enabled.

Instant Graemlins
   


Post New Topic  New Poll  Post A Reply Close Topic   Feature Topic   Move Topic   Delete Topic next oldest topic   next newest topic
 - Printer-friendly view of this topic
Hop To:


Contact Us | EgyptSearch!

(c) 2015 EgyptSearch.com

Powered by UBB.classic™ 6.7.3