Key Phases of Human Evolution Coincide with Flickers in Eastern Africa’s Climate

Peer-Reviewed Publication

UNIVERSITY OF COLOGNE

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Recovering the sediments
IMAGE: CHEW BAHIR CORING SITE, EXTRACTING A LINER FULL OF RECOVERED SEDIMENT MATERIAL FROM THE 280-M-LONG CORE: THE DAY SHIFT TRYING TO PULL THE LINER OUT WITH COMBINED FORCES view more CREDIT: FRANK SCHAEBITZ

Three distinct phases of climate variability in eastern Africa coincided with shifts in hominin evolution and dispersal over the last 620,000 years, an analysis of environmental proxies from a lake sediment record has revealed. The project explores the youngest chapter in human evolution by analysing lacustrine sediments in close vicinity to paleo-anthropological key sites in eastern Africa using scientific deep drilling. The research endeavour included more than 22 researchers from 19 institutions in 6 countries, and was led by Dr Verena Foerster at the University of Cologne’s Institute of Geography Education. The article ‘Pleistocene climate variability in eastern Africa influenced hominin evolution’ has now appeared in Nature Geoscience.

Despite more than half a century of hominin fossil discoveries in eastern Africa, the regional environmental context of the evolution and dispersal of modern humans and their ancestors is not well established. Particularly for the Pleistocene (or Ice Age) between 2,580,000 to 11,700 years ago, there are no continuous high-resolution paleo-environmental records available for the African continent.

The research team extracted two continuous 280-metre sediment cores from the Chew Bahir Basin in southern Ethiopia, an area where early humans lived and developed during the Pleistocene. Chew Bahir is very remotely situated in a deep tectonic basement in close vicinity to the Turkana area and the Omo-Kibish, key paleo-anthropological and archaeological sites. The cores yielded the most complete record for such a long period ever extracted in the area, revealing how different climates influenced the biological and cultural transformation of humans inhabiting the region.

An interdisciplinary team including geoscientists, sedimentologists, micro-paleontologists, geologists, geographers, geochemists, archaeologists, chronologists, and climate modellers worked towards recovering the two continuous sediment cores, from which so-called proxies (like microfossils or elemental variations) were used to glean data to reconstruct the region’s climate history. Archaeologists, evolutionary biologists, and evolutionary anthropologists then identified phases of climatic stress as well as more favourable conditions and interpreted how these factors changed human habitats, influencing human biological and cultural evolution as well as their dispersal.

Specifically, the scientists found that various anatomically diverse hominin groups inhabited the area during a phase of long-lasting and relatively stable humid conditions from approximately 620,000 to 275,000 years BP (Before Present). However, a series of shorter abrupt and extreme arid pulses interrupted this long generally stable and wet phase. Most likely, this resulted in a fragmentation of habitats, shifts in population dynamics and even the extinctions of local populations. As a result, small, reproductively and culturally isolated populations then had to adapt to dramatically transformed local environments, likely stimulating the appearance of the many geographically and anatomically distinct hominin groups and the separation of our modern human ancestors from archaic groups.

A phase with significant climate swings resulting in regularly transformed habitats in the area from approximately 275,000 to 60,000 years BP repeatedly resulted in environmental shifts from lush vegetation with deep fresh water lakes to highly arid landscapes with the extensive lakes reduced to small saline puddles. In this phase, the population groups gradually transitioned from Acheulean technologies (oval  hand axes made of stone and primarily associated with Homo ergaster/erectus) to more sophisticated Middle Stone Age technologies. This crucial phase also encompasses the emergence of Homo sapiens in eastern Africa as well as key human social, technological, and cultural innovations that could have buffered early Homo sapiens from the impacts of severe environmental changes. ‘These innovations, such as more varied toolkits and long-distance transport, would have equipped modern humans with an unprecedented adaptability to the repeated expansions and contractions of habitats,’ said Dr Foerster, the paper’s lead author.

The phase from approximately 60,000 to 10,000 years BP saw the most extreme environmental fluctuations, but also the most arid phase of the entire record, which could have acted as a motor for continuous indigenous cultural change. The scientists believe that the brief alignment of humid pulses in eastern Africa with wet phases in north-eastern Africa and the Mediterranean was key to opening favourable migration routes out of Africa on a roughly north-south axis along the East African Rift System (EARS) and into the Levant, facilitating the global dispersal of Homo sapiens.

‘In view of current threats to the human habitat from climate change and the overuse of natural resources through human activity, understanding how the relationship between climate and human evolution has become more relevant than ever,’ Foerster concluded.

This research is part of the Hominin Sites and Paleolakes Drilling Project (HSPDP). In order to evaluate the impact that different timescales and magnitudes of climatic shifts have had on the living conditions of early humans, the project has cored five lake archives of climate change during the last 3.5 million years. All five sites in Kenya and Ethiopia are located in close vicinity to paleoanthropological key sites covering various steps in human evolution, with the site in southern Ethiopia exploring the youngest chapter.

As part of HSPDP, the project has received funding from the International Continental Scientific Drilling Program (ICDP), the German Research Foundation (DFG), the Natural Environment Research Council (NERC), the National Science Foundation (NSF), and the DFG Collaborative Research Centre 806 ‘Our Way to Europe’. CRC 806 was based at the universities of Cologne, Bonn, and Aachen and received generous financial and infrastructural support from these institutions from 2009 to 2021.


JOURNAL

Nature Geoscience

DOI

10.1038/s41561-022-01032-y 

METHOD OF RESEARCH

Observational study

SUBJECT OF RESEARCH

Not applicable

ARTICLE TITLE

Pleistocene climate variability in eastern Africa influenced hominin evolution

ARTICLE PUBLICATION DATE

26-Sep-2022

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Ben Vorlich
September 27, 2022 2:33 am

The phase from approximately 60,000 to 10,000 years BP saw the most extreme environmental fluctuations, but also the most arid phase of the entire record, which could have acted as a motor for continuous indigenous cultural change.

BUT
‘In view of current threats to the human habitat from climate change and the overuse of natural resources through human activity, understanding how the relationship between climate and human evolution has become more relevant than ever,’ Foerster concluded.

These days it’s all our fault

Ron Long
Reply to  Ben Vorlich
September 27, 2022 3:32 am

He swings, he connects, Ben hits it out of the park.

Smart Rock
Reply to  Ben Vorlich
September 27, 2022 9:35 am

She has to say that or she won’t get another grant.

Apart from that nod to the elites who rule us, it’s a good study with new observations on the way rapid environmental changes drive evolution (of hominins in particular, but with applicability to evolution in general).

If it hadn’t been for the Pleistocene glaciation, we’d probably still be apes living in the African jungle and eating fruit.

AndyHce
Reply to  Smart Rock
September 27, 2022 1:46 pm

The entire Reset effort would have been unnecessary

David Blenkinsop
Reply to  Smart Rock
September 27, 2022 6:22 pm

The last Glacial Period ice sheets probably challenged humans so much, why, I’ll bet when they melted back, there was quite a tough and rugged civilization living under there..

patrick healy
Reply to  Smart Rock
September 30, 2022 7:57 am

Is “she” the one with the nice bum and long mane in the picture?

Reply to  Ben Vorlich
September 28, 2022 7:14 am

Also, its getting quite obvious that droughts and cold are the 2 biggest obstacles that man has to overcome and they both coincide.

Javier
September 27, 2022 2:36 am

Looking at the bright side of it, we are going to evolve faster with so much climate change.

Chaswarnertoo
Reply to  Javier
September 27, 2022 5:23 am

🤣

DonM
Reply to  Javier
September 27, 2022 9:27 am

I just hope the climate stabilizes before y’all catch up to, and maybe even pass, us higher evolved specimens.

Gary Pearse
Reply to  Javier
September 27, 2022 11:52 am

Javier, In the last 40yrs it looks like retrograde evolution or degeneration.

Retired_Engineer_Jim
Reply to  Gary Pearse
September 27, 2022 2:01 pm

But what would have happened if it had gotten colder, rather than warmer?

On the Outer Barcoo
Reply to  Gary Pearse
September 28, 2022 10:20 am

Recommended reading: “Nutrition and Physical Degeneration” by Weston A. Price

John Tillman
September 27, 2022 2:51 am

Genus Homo seems to have diverged from Australopithecus around the Pliocene-Pleistocene transition c. 2.588 Ma.

September 27, 2022 2:54 am

“Pleistocene (or Ice Age) between 2,580,000 to 11,700 years ago”
We are still in an ‘Ice Age'(any period when their is permanent ice in both the northern and southern hemispheres) and are simply in one of the many inter-glacial cycles of the the past two million years.

Chaswarnertoo
Reply to  bill bates
September 27, 2022 5:23 am

We seem to have got lucky and dodged the latest glaciation.

Reply to  Chaswarnertoo
September 28, 2022 7:16 am

lol, test this in about 3000 years

Dave Fair
Reply to  bill bates
September 27, 2022 1:16 pm

Yea, Bill, but the politicized “science” insists (as reflected here) the Holocene interglacial replaced the Pleistocene Ice Age. I wonder if that will ever be corrected.

Retired_Engineer_Jim
Reply to  Dave Fair
September 27, 2022 2:01 pm

Only time will tell.

fretslider
September 27, 2022 4:21 am

“human activity”

Is OK if it involves oval hand axes made of stone – primarily associated with Homo ergaster/erectus. Even more sophisticated Middle Stone Age technologies can be tolerated. But only just.

As the great Saint David told us: “humans are intruders”

“the relationship between climate and human evolution”

As a rule of thumb warm periods favour development – of civilisations

Last edited 2 months ago by strativarius
jeffery P
September 27, 2022 4:25 am

Over the last few thousand years, human evolution became primarily cultural. “Cultural” evolution includes technology..We no longer need to change physically to adapt to climate changes (“climate change” now includes everything), we only need to engineer better buildings or more efficient HVAC systems.

Paulete
September 27, 2022 5:23 am

Bearing some major geological cataclysm (eg mountain range formation), weather is one of the only speciation events on Earth. IF we are here it’s because climate changed in the past.

Tom Abbott
September 27, 2022 5:43 am

From the article: “‘In view of current threats to the human habitat from [human-caused] climate change”

What human-caused climate change?

n.n
Reply to  Tom Abbott
September 27, 2022 5:53 am

Another missing link in “science” inferred through models and faith… peer review.

Last edited 2 months ago by n.n
Richard Page
Reply to  Tom Abbott
September 27, 2022 7:34 am

The Green article of faith.

Peta of Newark
September 27, 2022 5:57 am

a two hundred and eighty metre sediment is All You Need To Know

Now go figure, especially as you talk about local extinctions

mkelly
Reply to  Peta of Newark
September 27, 2022 6:26 am

Sometimes you are a little to cryptic. I have no idea what your first sentence means because I still need to know.

fretslider
Reply to  mkelly
September 27, 2022 6:45 am

You do get used to it!

For example

cultural transformation of humans
culturally isolated populations
cultural evolution
indigenous cultural change

All from a 280m sediment core.

The scientists believe… 

Conjecture and speculation are part and parcel of many papers today.

Last edited 2 months ago by strativarius
Pflashgordon
Reply to  fretslider
September 27, 2022 10:27 am

Correct. And who is to refute their fairy tale? Go get your own cores, you denier!

Dave Fair
Reply to  fretslider
September 27, 2022 1:21 pm

“There is something fascinating about science. One gets such wholesale returns of conjecture out of such a trifling investment of fact.”
― Mark Twain, Life on the Mississippi

Olen
September 27, 2022 8:04 am

And all of this led to the modern world as man used resources were exploited.

Michael in Dublin
September 27, 2022 8:29 am

What is wonderful for those making these claims is that we have no time machine to go back and check up on their claims and even if we did with their dates are all over the place so we would not know which year to go to.

This is not unlike the new National Risk Assessment for Extreme Heat report saying that by 2053 there will be a heat belt across the USA with temperatures of over 125F. Yes, by 2053, when most of us will not be around to check these predictions. The weather people often get next week’s predictions wrong so can we can trust their predictions for 31 years hence?

H.R.
September 27, 2022 8:49 am

From the article: “[…] using scientific deep drilling.”


What the heck is the difference between scientific drilling and drilling? Are we supposed to be impressed? Do all the roughnecks have PhDs?

I guess the point is we have to believe them since it was scientific drilling as opposed to just core drilling.

That was just weird to me.

DonM
Reply to  H.R.
September 27, 2022 9:34 am

‘Scientific drilling’ requires 12 people standing around the core. If it was just ‘drilling’, there would be 3 guys in blue jump suits (rather than 5) and one boss for a total of 4.

Dave Fair
Reply to  DonM
September 27, 2022 1:26 pm

Actually, 7 PhDs came out to harass the workers for a photo op. All scientific work on the cores occurred at an airconditioned lab.

On the Outer Barcoo
September 27, 2022 10:21 am

The evolution of humans must be cognizant of what fuelled that growth.

An herbivorous animal has a bowel 26-times the length of its spine; a carnivorous animal has a bowel 9-times the length of its spine; the human bowel is 16-times the length of the spine, i.e, much like a carnivore, the protestations of vegans and vegetarians notwithstanding.

Judging human dentition and digestive tract physiology and bearing in mind that human stomach pH is matched only by hyenas and buzzards, it would appear that our ancestral family developed as opportunistic, omniverous, carrion eaters.

Grains were introduced into the human diet only about 10,000 years ago. Until then, our ancestors had survived without them for some seven million years.

Mike Dubrasich
Reply to  On the Outer Barcoo
September 27, 2022 1:21 pm

You’re close. Please see Catching Fire: How Cooking Made Us Human by Richard Wrangham.

It could be (I’m going out on a limb here) that “climate change” is NOT the be all end all of everything. Please note that no other animal writes commentary on websites, despite the fact that all critters experienced the same weather.

On the Outer Barcoo
Reply to  Mike Dubrasich
September 27, 2022 3:20 pm

The most primitive tools – hammer stones – were used by early hominins to crack the skulls of prey killed and devoured by predators.These predators consumed the easily accessible internal organs. The remnant odds & ends plus muscle meat were picked over by subsequent carrion eaters – hyenas and buzzards – that did not have unfettered access to the skull case with its rich store of fatty brain tissue. Hammer stones did the job of providing high energy nutrition. Long sticks (spears) were most likely used to disperse and fend off competing carrion eaters. Fire came later: rotting meat is much healthier and more palatable when cooked.

Pflashgordon
September 27, 2022 10:22 am

A drill rig with an experienced drill crew would have done a much more professional job with better core recoveries, and at FAR lower cost. What I see in the photo is about a dozen geeky scientists, improperly attired and lost as to how to recover and log cores. Knowing academics and grad students inexperience and lack of mechanical skills, I would consider whatever they concluded to be suspect. More fairy tales.

Gary Pearse
September 27, 2022 11:27 am

“An interdisciplinary team including geoscientists, sedimentologists, micro-paleontologists, geologists, geographers, geochemists, archaeologists, chronologists, and climate modellers worked towards…”

Only climate modelers archeologists and geographers in this long list aren’t geologists! The rest are. Yeah, geologists are ‘chronologists’, like carpenter is a ‘nail hammerer’ and a ‘board sawyer’

On the Outer Barcoo
Reply to  Gary Pearse
September 27, 2022 3:23 pm

As a geologist, I have hit mountains with a little hammer. And even licked rocks!

September 27, 2022 1:35 pm

Christopher, that’s pretty much
“We’re on The Team. Send money!”, as alluded above, I suggest.

Auto

ATheoK
September 28, 2022 6:25 am

The research team extracted two continuous 280-metre sediment cores from the Chew Bahir Basin in southern Ethiopia, an area where early humans lived and developed during the Pleistocene. Chew Bahir is very remotely situated in a deep tectonic basement

deep tectonic basement”, that is, a deep sediment basement regularly shaken very hard, with sediments that are also shaken hard from their origins.

Add in a lot of assumptions; ergo, whatever they want can be called ‘conclusive’.

September 28, 2022 1:44 pm

‘In view of current threats to the human habitat from climate change and the overuse of natural resources through human activity, understanding how the relationship between climate and human evolution has become more relevant than ever,’ Foerster concluded.

The relationship between climate and evolution has been broken since technology beyond the hand held stone axe and fire became part of the human experience. If climate changes to something inimical to human flourishing, humanity uses technology to create conditions that mitigate the changed climate. Silly scientists.

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