26
   

Does everyone agree that we evolved from Africa?

 
 
Olivier5
 
  1  
Reply Fri 23 Feb, 2018 07:53 am
@Olivier5,
More on the (admitedly crude) art of Neanderthal:


Cave Art May Have Been Handiwork Of Neanderthals
February 22, 20182:14 PM ET
CHRISTOPHER JOYCE

Tens of thousands of years ago, the first artists painted images on the walls of caves. They collected, painted and ground holes in shells, presumably to wear. It was the very first art, created by what we call "modern humans," or Homo sapiens.

Except, it turns out that some of that cave art may have been created by Neanderthals — our ancient and, by evolutionary standards, failed cousins. At least, that's what a team of scientists is now claiming.

The painted caves were discovered in Spain. The walls were the canvasses, and the paintings are bold and clearly not some kind of smeary accident. The paint used was red ochre, from soil mixed with water.

One geometric design looks like part of a ladder, forming rectangles. There are stencils where someone pressed a hand up against the wall and then apparently blew liquid ochre over it. Someone painted swirls of bright red dots and patches onto flowing curtains of stalactites that hang from the cave ceilings.

Most of this work has long been known and attributed to humans, who originally came from Africa and are believed to have arrived in Spain about 45,000 years ago.

But here's the catch. New tests on the rock and calcium carbonate that formed over parts of the ochre show that they were painted 65,000 years ago. That's about 20,000 years before the first modern humans got there.

"The only species that were around at that time were Neanderthals," explains Alistair Pike, an archaeologist from the University of Southampton in England who was part of the team that did the work. "So, therefore, the paintings must've been made by them."

More:  https://www.npr.org/sections/health-shots/2018/02/22/587662842/cave-art-may-have-been-handiwork-of-neanderthals

https://media.npr.org/assets/img/2018/02/21/inside-cave-1-9feda7d7471741d60203d1e3f6ff58c3c3e474aa-s1100-c15.jpg
The scalariform (ladder shape) painting composed of red horizontal and vertical lines (center left) dates to older than 64,000 years and must have been made by Neanderthals.
farmerman
 
  1  
Reply Fri 23 Feb, 2018 09:11 am
@Olivier5,
Hmm, maybe Kline was a neanderthal.
Olivier5
 
  1  
Reply Fri 23 Feb, 2018 11:00 am
@farmerman,
You got me googling. What i like most in you farmer, is this combination of scientific and artistic literacy. Most people are either one or the other.
farmerman
 
  2  
Reply Fri 23 Feb, 2018 11:02 am
@Olivier5,
I used to paint rooms to earn money when chemistry companies didnt like to hire me.

I used to get havily stoned and then make up color combinations.
Olivier5
 
  2  
Reply Fri 23 Feb, 2018 11:05 am
@farmerman,
Huhuh... And you wonder why chemist labs wouldn't hire you? :-)
farmerman
 
  2  
Reply Fri 23 Feb, 2018 12:06 pm
@Olivier5,
not a clue.
Olivier5
 
  1  
Reply Fri 23 Feb, 2018 01:10 pm
@farmerman,
Maybe your hair.
farmerman
 
  4  
Reply Fri 23 Feb, 2018 03:59 pm
@Olivier5,
I always wear my cheese -eter baseball cp'
It sy

MAKE AMERICA GRATE AGAIN
Olivier5
 
  1  
Reply Sat 24 Feb, 2018 05:18 am
@farmerman,
This cap SHOULD exist. Or you ought to make a design and sell it.
0 Replies
 
Pamela Rosa
 
  -2  
Reply Thu 19 Jul, 2018 03:44 pm
Modern human origins: multiregional evolution of autosomes and East Asia origin of Y and mtDNA
https://www.biorxiv.org/content/early/2017/01/18/101410
0 Replies
 
Pamela Rosa
 
  0  
Reply Tue 24 Jul, 2018 02:24 pm
Did Our Species Evolve in Subdivided Populations across Africa, and Why Does It Matter?

https://www.cell.com/trends/ecology-evolution/fulltext/S0169-5347(18)30117-4
farmerman
 
  2  
Reply Tue 24 Jul, 2018 02:36 pm
@Pamela Rosa,
I think its more likely that we spread out from the african continent to the rest of the Eurasian area, much much earlier than weve given up in the past.
0 Replies
 
Leadfoot
 
  1  
Reply Wed 25 Jul, 2018 09:23 am
The 'Out of Africa' story gets more iffy all the time.
Going to need the 'convergent evolution' gambit if this gets any more complicated..
Blickers
 
  2  
Reply Wed 25 Jul, 2018 10:31 am
@Leadfoot,
Quote Leadfoot:
Quote:
The 'Out of Africa' story gets more iffy all the time.
Hardly, the basic chain of events gets more and more solid and proven all the time.

The referenced article above, for instance, does not go against the Out-Of-Africa Theory at all, it is quite consistent with it.

In the beginning there was the "Multi-regional" theory which said that Homo Sapiens evolved from hominids in all the various regions of the world-Asia, Europe, Africa, all over. Since that theory would make it impossible that today's people who are descended from hominid groups who were separated for millions of years could produce offspring at all, (let alone as easily as they do), the multiregionalists had to cobble together some idea of "gene flow" in response. Now, that was iffy.

The Out-Of-Africa Theory explains why modern Asians have no problem easily producing viable offspring with Europeans and Africans-Asians, Europeans and Africans weren't separated for very long, (70,000 years at the max), so they did not evolve enough away from each other to give difficulty with producing offspring. Now if Asians and Africans were separated from each other for 700,000 years or so, (10 times longer), there definitely would be some problems in reproduction-it could happen, but not as easily or as often per mating.

The major modification was the discovery that Neanderthal and Denisovan genes got into the gene pool some 50,000 years ago. However, there is no evidence that these inter-species offspring were produced easily and at the same rate as offspring from modern people from different continents. Quite the opposite, the evidence that we are slowly losing our Neanderthal heritage more and more suggests that Neanderthals were more different from us genetically than Europeans, Asians and Africans are from each other, and therefore the genetic matings did not produce offspring at the same rate as the matings among modern people.

Thr Out-Of-Africa Theory remains very much in place. It's the only theory which explains why modern Asians and modern Africans can easily have kids together.
farmerman
 
  1  
Reply Wed 25 Jul, 2018 10:39 am
@Leadfoot,
The greatest number of varieties of Australopithecus and Homo still are only found in Africa. Thats usually good proof that Africa was the cradle. I think the arguments now is going to be re-adjusting the "OOA" timelines around H.ergaster but before H. heidelbergensis.
Its not that we doubt that humanity evolved in Africa, we are investigating when it left and colonized the rest of the world.
0 Replies
 
farmerman
 
  1  
Reply Wed 25 Jul, 2018 10:41 am
@Leadfoot,
A "convergent evolution gambit" needs to have some parent species that converge toward another unrelated species. thats not whats happening here
Leadfoot
 
  1  
Reply Thu 26 Jul, 2018 12:57 pm
@Blickers,
Yeah, I wasn’t trying to support the East Asian Origin story. I was thinking more about the original out of Africa story including the 'cradle of civilization ' in the Euphrates Valley. That theory has been blown to hell last I heard. Earlier and earlier Homo fossils keep showing up as far away as Morocco.

I would add that The honorific of 'Homo' or 'Sap' is obviously arbitrary.
Blickers
 
  1  
Reply Thu 26 Jul, 2018 03:21 pm
@Leadfoot,
One of the issues with online discussions of the Out-Of-Africa Theory is the fact that it only deals with Homo Sapiens coming out of Africa in the last 100,000 or so years ago. I've seen many posts on YouTube where somebody says found remains were found of a 7 Million year old fossil in Europe that conceivably might have belonged to a line that, millions of years later, would develop into the human line and claim that "this blows the Out-Of-Africa Theory away!!"

Most of these posts are by white supremacists, and most of them are either Russian or extreme right types who get their info from Russia's online troll factory.

Be that as it may, the Out-Of-Africa Theory doesn't deal with Homo Erectus, Homo Habilis, the Dmanisi peoples in European Georgia, or any of that. It deals with modern hunter-gathers with modern intelligence leaving Africa to settle in new places when the climate made it possible for them to do so. And the time frame is usually given around 70,000 years ago. We have found remains of what many call modern humans in Israel around 100,000 years ago, but Israel is just outside Africa and so far as we know, the settlements didn't get much farther away than that, (there is a finding in India that is up in the air, I believe).

As far as I'm concerned, even if we find remains far outside Africa of populations of modern appearing groups even 120,000 years or so ago, even that would not disprove the Out-Of-Africa Theory, only modify it.

The modern thinking is that there were two main groups that left, one older wave around 70,000 years ago and another newer wave around 45,000 years ago. The older wave never developed large population numbers, so when the second larger wave came 50,000 years ago they basically obliterated all traces of the older wave except for the South Sea Islands and Australia.

If we ever do confirm some findings of modern looking people in India or elsewhere that are 120,000 years old, all it would mean is that an even earlier wave of Homo Sapiens left around 120,000 years ago and lasted until the later two waves came and drove them out. Who knows, perhaps those people who left Africa 120,000 years ago are the people who are the mystery contributors to the native Australians' genome that they are talking about-maybe their last holdout was Australia too, just like Australia was the last holdout for the people who left 70,000 years ago.
farmerman
 
  1  
Reply Thu 26 Jul, 2018 04:45 pm
@Blickers,
has anyone actually surrendered such a sample for study?? That's about the same age as Sahellanthropus and older than Orrorin(both of which were found in desert and mixed ash beds in Chad and Kenya respectively.
Blickers
 
  1  
Reply Thu 26 Jul, 2018 08:58 pm
@farmerman,
7.2-million-year-old pre-human remains found in the Balkans
New hypothesis about the origin of humankind suggests oldest hominin lived in Europe
Date: May 23, 2017
Source: University of Toronto

Summary:
Scientists analyzing 7.2 million-year-old fossils uncovered in modern-day Greece and Bulgaria suggest a new hypothesis about the origins of humankind, placing it in the Eastern Mediterranean and not -- as customarily assumed -- in Africa, and earlier than currently accepted. The researchers conclude that Graecopithecus freybergi represents the first pre-humans to exist following the split from the last chimpanzee-human common ancestor.


https://www.sciencedaily.com/images/2017/05/170523083548_1_540x360.jpg

The common lineage of great apes and humans split several hundred thousand earlier than hitherto assumed, according to an international research team headed by Professor Madelaine Böhme from the Senckenberg Centre for Human Evolution and Palaeoenvironment at the University of Tübingen and Professor Nikolai Spassov from the Bulgarian Academy of Sciences. The researchers investigated two fossils of Graecopithecus freybergi with state-of-the-art methods and came to the conclusion that they belong to pre-humans. Their findings, published today in two papers in the journal PLOS ONE, further indicate that the split of the human lineage occurred in the Eastern Mediterranean and not -- as customarily assumed -- in Africa.

Present-day chimpanzees are humans' nearest living relatives. Where the last chimp-human common ancestor lived is a central and highly debated issue in palaeoanthropology. Researchers have assumed up to now that the lineages diverged five to seven million years ago and that the first pre-humans developed in Africa. According to the 1994 theory of French palaeoanthropologist Yves Coppens, climate change in Eastern Africa could have played a crucial role. The two studies of the research team from Germany, Bulgaria, Greece, Canada, France and Australia now outline a new scenario for the beginning of human history.

Dental roots give new evidence

The team analyzed the two known specimens of the fossil hominid Graecopithecus freybergi: a lower jaw from Greece and an upper premolar from Bulgaria. Using computer tomography, they visualized the internal structures of the fossils and demonstrated that the roots of premolars are widely fused.

"While great apes typically have two or three separate and diverging roots, the roots of Graecopithecus converge and are partially fused -- a feature that is characteristic of modern humans, early humans and several pre-humans including Ardipithecus and Australopithecus," said Böhme.

The lower jaw, nicknamed 'El Graeco' by the scientists, has additional dental root features, suggesting that the species Graecopithecus freybergi might belong to the pre-human lineage. "We were surprised by our results, as pre-humans were previously known only from sub-Saharan Africa," said Jochen Fuss, a Tübingen PhD student who conducted this part of the study.

Furthermore, Graecopithecus is several hundred thousand years older than the oldest potential pre-human from Africa, the six to seven million year old Sahelanthropus from Chad. The research team dated the sedimentary sequence of the Graecopithecus fossil sites in Greece and Bulgaria with physical methods and got a nearly synchronous age for both fossils -- 7.24 and 7.175 million years before present. "It is at the beginning of the Messinian, an age that ends with the complete desiccation of the Mediterranean Sea," Böhme said.

Professor David Begun, a University of Toronto paleoanthropologist and co-author of this study, added, "This dating allows us to move the human-chimpanzee split into the Mediterranean area."

Environmental changes as the driving force for divergence

As with the out-of-East-Africa theory, the evolution of pre-humans may have been driven by dramatic environmental changes. The team led by Böhme demonstrated that the North African Sahara desert originated more than seven million years ago. The team concluded this based on geological analyses of the sediments in which the two fossils were found. Although geographically distant from the Sahara, the red-colored silts are very fine-grained and could be classified as desert dust. An analysis of uranium, thorium, and lead isotopes in individual dust particles yields an age between 0.6 and 3 billion years and infers an origin in Northern Africa.

Moreover, the dusty sediment has a high content of different salts. "These data document for the first time a spreading Sahara 7.2 million years ago, whose desert storms transported red, salty dusts to the north coast of the Mediterranean Sea in its then form," the Tübingen researchers said. This process is also observable today. However, the researchers' modelling shows that, with up to 250 grams per square meter and year, the amount of dust in the past considerably exceeds recent dust loadings in Southern Europe more than tenfold, comparable to the situation in the present-day Sahel zone in Africa.

Fire, grass, and water stress

The researchers further showed that, contemporary to the development of the Sahara in North Africa, a savannah biome formed in Europe. Using a combination of new methodologies, they studied microscopic fragments of charcoal and plant silicate particles, called phytoliths. Many of the phytoliths identified derive from grasses and particularly from those that use the metabolic pathway of C4-photosynthesis, which is common in today's tropical grasslands and savannahs. The global spread of C4-grasses began eight million years ago on the Indian subcontinent -- their presence in Europe was previously unknown.

"The phytolith record provides evidence of severe droughts, and the charcoal analysis indicates recurring vegetation fires," said Böhme. "In summary, we reconstruct a savannah, which fits with the giraffes, gazelles, antelopes, and rhinoceroses that were found together with Graecopithecus," Spassov added

"The incipient formation of a desert in North Africa more than seven million years ago and the spread of savannahs in Southern Europe may have played a central role in the splitting of the human and chimpanzee lineages," said Böhme. She calls this hypothesis the North Side Story, recalling the thesis of Yves Coppens, known as East Side Story.

The findings are described in two studies pubished in PLOS ONE titled "Potential hominin affinities of Graecopithecus from the late Miocene of Europe" and "Messinian age and savannah environment of the possible hominin Graecopithecus from Europe."

Story Source:

Materials provided by University of Toronto. Note: Content may be edited for style and length.

Journal References:

Jochen Fuss, Nikolai Spassov, David R. Begun, Madelaine Böhme. Potential hominin affinities of Graecopithecus from the Late Miocene of Europe. PLOS ONE, 2017; 12 (5): e0177127 DOI: 10.1371/journal.pone.0177127
Madelaine Böhme, Nikolai Spassov, Martin Ebner, Denis Geraads, Latinka Hristova, Uwe Kirscher, Sabine Kötter, Ulf Linnemann, Jérôme Prieto, Socrates Roussiakis, George Theodorou, Gregor Uhlig, Michael Winklhofer. Messinian age and savannah environment of the possible hominin Graecopithecus from Europe. PLOS ONE, 2017; 12 (5): e0177347 DOI: 10.1371/journal.pone.0177347



University of Toronto. "7.2-million-year-old pre-human remains found in the Balkans: New hypothesis about the origin of humankind suggests oldest hominin lived in Europe." ScienceDaily. ScienceDaily, 23 May 2017. <www.sciencedaily.com/releases/2017/05/170523083548.htm>.

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