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Migration of Early Humans From Africa Aided By Wet Weather
Science Daily ^ | 8-30-2007 | Geological Society of America

Posted on 08/30/2007 10:15:20 AM PDT by blam

Source: Geological Society of America
Date: August 30, 2007

Migration of Early Humans From Africa Aided By Wet Weather

Science Daily — The African origin of early modern humans 200,000--150,000 years ago is now well documented, with archaeological data suggesting that a major migration from tropical east Africa to the Levant took place between 130,000 and 100,000 years ago via the presently hyper-arid Saharan-Arabian desert.

This migration was dependent on the occurrence of wetter climate in the region. Whereas there is good evidence that the southern and central Saharan-Arabian desert experienced increased monsoon precipitation during this period, no unequivocal evidence has been found for a corresponding rainfall increase in the northern part of the migration corridor, including the Sinai-Negev land bridge between Africa and Asia.

Passage through this "bottleneck" region would have been dependent on the development of suitable climate conditions.

Vaks et al. present a reconstruction of paleoclimate in the Negev Desert based on absolute uranium series dating of carbonate cave deposits (speleothems). Speleothems only form when rainwater enters the groundwater system and vegetation grows above a cave.

Today the climate in the Negev Desert is very arid and speleothems do not form, but their presence in a number of caves clearly indicates that conditions were wetter in the past. Vaks et al. dated 33 speleothem samples from five caves in the central and southern Negev Desert.

The ages of these speleothems show that the last main period of increased rainfall occurred between 140,000 and 110,000 years ago. The climate during this time consisted of episodic wet events that enabled the deserts of the northeastern Sahara, Sinai, and the Negev to become more hospitable for the movement of early modern humans.

The simultaneous occurrence of wet periods in the northern and southern parts of Saharan-Arabian desert could have led to the disappearance of the desert barrier between central Africa and the Levant.

The humid period in the Negev Desert between 140,000 and 110,000 years ago was preceded and followed by essentially unbroken arid conditions; thus creating a climatic "window" for early modern human migration to the Levant. Vaks et al.'s study suggest that climate change had an important limiting role in the timing of dispersal of early modern humans out of Africa.

Reference: Desert speleothems reveal climatic window for African exodus of early modern humans, Anton Vaks, Hebrew University, Institute of Earth Sciences, Edmond Safra Givat Ram Campus, Jerusalem 91904, Israel; et al. pages 831-834.

Note: This story has been adapted from a news release issued by Geological Society of America.


TOPICS: News/Current Events
KEYWORDS: africa; godsgravesglyphs; humans; migration; weather

1 posted on 08/30/2007 10:15:24 AM PDT by blam
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To: SunkenCiv

GGG Ping.


2 posted on 08/30/2007 10:15:58 AM PDT by blam (Secure the border and enforce the law)
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To: blam

And global warming...


3 posted on 08/30/2007 10:18:12 AM PDT by 2banana (My common ground with terrorists - they want to die for islam and we want to kill them)
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To: 2banana

So, we are all descendants of wetblacks?.........


4 posted on 08/30/2007 10:19:30 AM PDT by Red Badger (ALL that CARBON in ALL that oil & coal was once in the atmospere. We're just putting it back!)
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To: Red Badger
So, we are all descendants of wetblacks?.........

Of Africa - make sure you check the right box on your next minority only scholarship, set aside and quota job...

5 posted on 08/30/2007 10:25:00 AM PDT by 2banana (My common ground with terrorists - they want to die for islam and we want to kill them)
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To: blam
If I read the ice core historic graph right, this would have been during the last interglacial maximum. Warm is good for human life? Who knew?
6 posted on 08/30/2007 10:26:15 AM PDT by colorado tanker (I'm unmoderated - just ask Bill O'Reilly)
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To: blam

I thought everyone knew the forbidden zone was once a paradise!

7 posted on 08/30/2007 10:27:13 AM PDT by meandog ((Romney and Giuliani: Just like Bill Clinton, duplicitous draft-dodgers))
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To: 2banana

When the census comes I check three boxes, white/caucasian, Asian, and white/hispanic.................


8 posted on 08/30/2007 10:28:49 AM PDT by Red Badger (ALL that CARBON in ALL that oil & coal was once in the atmospere. We're just putting it back!)
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To: blam

YEC INTREP


9 posted on 08/30/2007 10:30:22 AM PDT by LiteKeeper (Beware the secularization of America; the Islamization of Eurabia)
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To: blam

If we rule out boredom and wanderlust in these early men we must consider food shortages and inclement climate conditions.

Why leave a virtual paradise where the food grows on trees and bushes, the forest floor makes a comfortable bed, the water runs clear and plentiful and time clocks are millenia in the unanticipated future?


10 posted on 08/30/2007 10:30:39 AM PDT by Old Professer (The critic writes with rapier pen, dips it twice, and writes again.)
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To: blam

i still like how they open.....

the origin of early humans in africa...blah blah blah...is well documented. huh how about a theory?

when you build your house of cards on sand....


11 posted on 08/30/2007 10:34:16 AM PDT by applpie
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To: Old Professer
Why leave a virtual paradise where the food grows on trees and bushes, the forest floor makes a comfortable bed, the water runs clear and plentiful and time clocks are millenia in the unanticipated future?

I dunno, I wonder why Peary and Byrd explored the arctic, Admunsen the antarctic, why Hillary climbed Everest, why Burton explored the source of the Nile and why Stanley looked for Livingston...because it was there?

12 posted on 08/30/2007 10:44:25 AM PDT by meandog ((Romney and Giuliani: Just like Bill Clinton, duplicitous draft-dodgers))
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To: Old Professer
If we rule out boredom and wanderlust in these early men we must consider food shortages and inclement climate conditions.

One more reason. Why did the early Europeans leave for America?

Persecution.

Those places in Africa from where humans spread, humans still live, don't they? Maybe the ones that left, were chased away.

13 posted on 08/30/2007 10:45:27 AM PDT by CarrotAndStick (The articles posted by me needn't necessarily reflect my opinion.)
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To: applpie
the origin of early humans in africa...blah blah blah...is well documented. huh how about a theory?

Uh, right, and the earth is still just 6,000 years old according to the Bible...

14 posted on 08/30/2007 10:46:04 AM PDT by meandog ((Romney and Giuliani: Just like Bill Clinton, duplicitous draft-dodgers))
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To: blam
The ages of these speleothems show that the last main period of increased rainfall occurred between 140,000 and 110,000 years ago.

So, it looks to be a long time until the Negev is once more "The Land of Milk and Honey".

15 posted on 08/30/2007 10:49:12 AM PDT by glorgau
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To: Old Professer
Why leave a virtual paradise where the food grows on trees and bushes, the forest floor makes a comfortable bed, the water runs clear and plentiful and time clocks are millenia in the unanticipated future?


16 posted on 08/30/2007 10:50:14 AM PDT by frithguild (The Freepers moved as a group, like a school of sharks sweeping toward an unaware and unarmed victim)
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To: meandog

Totally out of the question — the earliest man had no knowledge of his whereabouts or that there was even a larger world out there.

As foragers they likey traveled only as far as daylight would allow a roundtrip.


17 posted on 08/30/2007 10:58:29 AM PDT by Old Professer (The critic writes with rapier pen, dips it twice, and writes again.)
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To: frithguild

That’s what they get for coming down out of the safety of the trees.


18 posted on 08/30/2007 10:59:51 AM PDT by Old Professer (The critic writes with rapier pen, dips it twice, and writes again.)
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To: Old Professer
As foragers they likely traveled only as far as daylight would allow a round trip.

Again, unless the ones that stayed behind, hadn't chased the "foragers" away, in the first place.

Persecution still is an excellent motivator for abandoning known lands for newer ones.

19 posted on 08/30/2007 11:52:43 AM PDT by CarrotAndStick (The articles posted by me needn't necessarily reflect my opinion.)
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To: blam

“Out of Africa” is being proven false, one new discovery at a time.


20 posted on 08/30/2007 11:54:36 AM PDT by pabianice
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To: CarrotAndStick

Is your argument based on population pressures or simple malevolence?


21 posted on 08/30/2007 12:40:05 PM PDT by Old Professer (The critic writes with rapier pen, dips it twice, and writes again.)
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To: Old Professer

Both, but the latter factor to a somewhat greater extent than the former.


22 posted on 08/30/2007 12:49:30 PM PDT by CarrotAndStick (The articles posted by me needn't necessarily reflect my opinion.)
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To: blam

All of N. African continent once had a wetter climate. Bones of non-desert animals have been found there.

Remember the recent theory about the Sphinx showing unmistakable signs of weathering from water?


23 posted on 08/30/2007 1:10:42 PM PDT by wildbill
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To: wildbill
"Remember the recent theory about the Sphinx showing unmistakable signs of weathering from water?"

REDATING THE GREAT SPHINX OF GIZA

by Dr. Robert M. Schoch © 1992

" If the Great Sphinx of Giza was weathered heavily, and at an early period in its existence, by precipitation, this suggests that it initially may have been carved prior to the last great period of major precipitation in this part of the Nile Valley. Egypt was subjected to erratic floods and what is sometimes referred to as the "Nabtian Pluvial" (a period of relatively heavy rainfall) from 12,000 or 10,000 to about 5,000 years ago; and it has been suggested that there were sporadic but relatively heavy rains during the Fourth Millennium (4000 to 3000 B.C.), and a less and climate along the Nile as late as 2350 B.C. (with relatively wetter conditions and unusually high Nile inundations recorded sporadically during historical times).[10] "

24 posted on 08/30/2007 2:11:36 PM PDT by blam (Secure the border and enforce the law)
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To: blam

25 posted on 08/30/2007 2:14:44 PM PDT by evets (beer)
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To: blam; StayAt HomeMother; Ernest_at_the_Beach; 1ofmanyfree; 24Karet; 3AngelaD; 49th; ...
Thanks Blam.

To all -- please ping me to other topics which are appropriate for the GGG list. Thanks.
Please FREEPMAIL me if you want on or off the
"Gods, Graves, Glyphs" PING list or GGG weekly digest
-- Archaeology/Anthropology/Ancient Cultures/Artifacts/Antiquities, etc.
Gods, Graves, Glyphs (alpha order)

26 posted on 08/30/2007 8:12:21 PM PDT by SunkenCiv (Profile updated Wednesday, August 29, 2007. https://secure.freerepublic.com/donate/)
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To: blam

First historical example of white flight.


27 posted on 08/30/2007 8:17:53 PM PDT by U S Army EOD (Say Cheese.)
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To: SunkenCiv
Archaeological Sites in the Libyan Desert

Wadi Bakht A long wadi along the south-eastern side of the Gilf Kebir. A large dune blocked the wadi near it's middle, forming an extensive lake behind the sand dam. Unlike Ard al Akhdar, the dune is still present, and the lakebed is uneroded, as if it were drained just a few weeks ago. The shores and lakebed are littered with the traces of the prehistoric inhabitants.

28 posted on 08/30/2007 8:55:05 PM PDT by Fred Nerks (Fair dinkum!)
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To: meandog

Brilliant — not
Give it a rest


29 posted on 08/30/2007 10:14:46 PM PDT by ValerieTexas
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To: SunkenCiv
The African origin of early modern humans 200,000--150,000 years ago is now well documented...

I guess they wrote travelogues.
The African origin of early modern humans is increasingly disputed. "News" like this just looks like desperation to hold on to a sacred old theory in danger of losing out to new discoveries.

30 posted on 08/30/2007 10:18:57 PM PDT by ValerieTexas
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To: Fred Nerks

But it’s *dry* heat...


31 posted on 08/31/2007 7:58:44 PM PDT by SunkenCiv (Profile updated Wednesday, August 29, 2007. https://secure.freerepublic.com/donate/)
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To: SunkenCiv
http://www.carlo-bergmann.de/Discoveries/discovery.htm

....................

SUPERCROC "SuperCroc" Fossil Found in Sahara

and we all know how corcodiles LOVE *dry* heat!

32 posted on 08/31/2007 9:39:29 PM PDT by Fred Nerks (Fair dinkum!)
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To: ValerieTexas

“The African origin of early modern humans is increasingly disputed.”

By whom, in which journals, at which institutions, and based on what evidence?


33 posted on 09/01/2007 12:04:05 AM PDT by 49th (this space for rent)
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To: 49th; ValerieTexas

New Fossil Study Rejects “Eve Theory” And Supports Diverse Ancestry Of Modern Humans

The ancestors of modern humans came from many different regions of the world, not just a single area, according to a University of Michigan study published in the current (Jan. 12) issue of Science. The study, by U-M anthropologist Milford H. Wolpoff and colleagues, is one of just a few to base its controversial conclusion about the origin of the human species on a comparison of actual human fossils-—early modern and archaic fossil skulls from around the world...

http://www.sciencedaily.com/releases/2001/01/010111194453.htm


34 posted on 09/01/2007 12:24:52 AM PDT by Fred Nerks (Fair dinkum!)
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To: blam; StayAt HomeMother; Ernest_at_the_Beach; 1ofmanyfree; 24Karet; 3AngelaD; 49th; ...
Thanks Blam. I have a feeling that the Digest will be delayed until tomorrow. I've got to work at 4 (it's 1:20 PM here); the analog board on my iMac died a few days ago, so I've had to switch to the trusty (recently upgraded) PowerMac 7600, rely on a USB flash drive for my GGG updated 'fo; and I spent a good hour tracking down a mouse driver and fiddlin'.

To all -- please ping me to other topics which are appropriate for the GGG list. Thanks.
Please FREEPMAIL me if you want on or off the
"Gods, Graves, Glyphs" PING list or GGG weekly digest
-- Archaeology/Anthropology/Ancient Cultures/Artifacts/Antiquities, etc.
Gods, Graves, Glyphs (alpha order)

35 posted on 09/01/2007 11:20:58 AM PDT by SunkenCiv (Profile updated Wednesday, August 29, 2007. https://secure.freerepublic.com/donate/)
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To: SunkenCiv

Hidden in General Chat already. Someone sure doesn’t want anyone to see science stuff on FR.


36 posted on 09/01/2007 11:26:38 AM PDT by ASA Vet
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To: SunkenCiv

Disregard, I was wrong. Meant to post on the DNA found in chewing of leaves thread.


37 posted on 09/01/2007 11:28:02 AM PDT by ASA Vet
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To: ValerieTexas

It’s inevitable that the global warming propaganda follows the same path of development. :’)


38 posted on 09/01/2007 11:56:27 AM PDT by SunkenCiv (Profile updated Wednesday, August 29, 2007. https://secure.freerepublic.com/donate/)
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To: ASA Vet

Science topics are supposed to be posted in Chat (which is where the Topics selector has headings like “Astronomy” and “Science”) — FreeRepublic is primarily a political site.


39 posted on 09/01/2007 12:05:17 PM PDT by SunkenCiv (Profile updated Wednesday, August 29, 2007. https://secure.freerepublic.com/donate/)
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To: Old Professer
Why leave a virtual paradise where the food grows on trees and bushes, the forest floor makes a comfortable bed, the water runs clear and plentiful and time clocks are millenia in the unanticipated future?

In the early era of modern humans between 120-200kya they were already evolved to jog over 50 miles a day on a near perpetual basis and swim large channels separating the east coast beaches in the region where all existing evidence suggests they lived. A long period of good weather and rainfall to the immediate north of their domain would simply give them expanded room to explore.

40 posted on 09/02/2007 9:27:02 AM PDT by shuckmaster
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To: shuckmaster

Gump! Is that you??


41 posted on 09/02/2007 9:30:42 AM PDT by Old Professer (The critic writes with rapier pen, dips it twice, and writes again.)
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To: blam
Good find, Blam. This falls right into the time frames suggested by Oppenheimer
42 posted on 09/02/2007 9:32:58 AM PDT by shuckmaster
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To: shuckmaster

Run for Scotland’s Children

http://www.runglasgow.org/senior/prepare/training3.php


43 posted on 09/02/2007 9:33:17 AM PDT by Old Professer (The critic writes with rapier pen, dips it twice, and writes again.)
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To: Old Professer
"Gump! Is that you??"

In Bayou La Batre, hit by Katrina, movie drama becomes all too real

44 posted on 09/02/2007 10:10:38 AM PDT by blam (Secure the border and enforce the law)
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To: blam

“The prices for the fuel to run the boats — just like for automobile gasoline — have been very high in recent years. Nonetheless, Gulf shrimpers must now compete with the cheap frozen shrimp imported from countries with lower labor costs.”

That’s not news, everybody knows that Chinese shrimp work for sesame nuts.


45 posted on 09/02/2007 10:46:16 AM PDT by Old Professer (The critic writes with rapier pen, dips it twice, and writes again.)
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46 posted on 09/15/2008 10:08:23 PM PDT by SunkenCiv (https://secure.freerepublic.com/donate/_______Profile hasn't been updated since Friday, May 30, 2008)
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