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Modern Human Origins

IMHO the research and analysis are sound, but ...

Let's not allow the speculative conclusion(s) to get overly specific about the geographic location of a hypothetical ancestral homeland.

The results of this genomic survey pinpoint the geographic locale where the presumed ancestral genome is most evident nowadays. The one element of possible migration that seems to be missing is that which pertains to the contemporary population exemplifying this ancestral genomic profile.

Phrased another way ... Pointing to Botswana as the ancestral homeland entails a big assumption that the ancestral genome remained relatively fixed in its original location.

We now know where the folks most genetically akin to modern humans' ancestors live now. This doesn't necessarily prove they lived in the same place then.
 
I think this best fits here.

Domestic animals’ cuteness and humans’ relatively flat faces may be the work of a gene that controls some important developmental cells, a study of lab-grown human cells suggests.

Some scientists are touting the finding as the first real genetic evidence for two theories about domestication. One of those ideas is that humans domesticated themselves over many generations, by weeding out hotheads in favor of the friendly and cooperative (SN: 7/6/17). As people supposedly selected among themselves for tameness traits, other genetic changes occurred that resulted in humans, like other domesticated animals, having a different appearance than their predecessors. Human faces are smaller, flatter and have less prominent brow ridges than Neandertal faces did, for instance.

Domesticated animals look different from their wild counterparts as well. Shorter snouts, curly tails, floppy ears and spotted coats are all traits that tend to pop up in domesticated animals. But until recently, no one had an explanation for this “domestication syndrome.”
Then in 2014, three scientists proposed that as people selected animals for tameness, they also happened to select for genetic changes that slightly hamper movement of some developmentally important cells (SN: 7/14/14). These neural crest cells are present early in embryonic development and migrate to different parts of the embryo where they give rise to many tissues, including bones and cartilage in the face, smooth muscles, adrenal glands, pigment cells and parts of the nervous system. The researchers’ idea was that mild genetic changes might produce neural crest cells that don’t move as well, leading to domestic animals’ cuddlier look.

https://www.sciencenews.org/article/gene-facial-development-hints-humans-domesticated-themselves
 
Oh no! Bambi was a knuckle-dragger!

An international team of researchers has concluded that the so-called "enigmatic hominoid" did not walk upright and was also not a tree climber. In their paper published in Proceedings of the National Academy of Sciences, the group describes their in-depth study of the skeletal remains of Oreopithecus bambolii and what they learned from it.

O. bambolii was a primate living in what is now Sardinia and Tuscany approximately 6.7 to 8.3 million years ago. Evidence of its existence was first discovered as far back as 1872. Since that time, scientists have debated its primary means of locomotion. Some have suggested that it was a tree climber, others disagreed, insisting it had evolved to become an upright walking terrestrial creature. Over time, it has come to be known as the "enigmatic hominoid." In his new effort, the researchers sought to settle the debate once and for all by studying the most complete skeleton that has ever been found—one unearthed in 1958 while workers were digging a coal mine. Prior research had shown the skeleton to be that of a 30-kilo male.

https://phys.org/news/2019-12-enigmatic-hominoid-upright-tree-climber.html
 
Of the multiple Homo species identified to date, only one survived to the present day. Why is that? Newly published research indicates the extinction of the other Homo species exhibits a strong correlation with significant climate changes.
Early Human Species Likely Driven to Extinction by Climate Change

Of the six or more different species of early humans, all belonging to the genus Homo, only we Homo sapiens have managed to survive. Now, a study reported in the journal One Earth today (October 15, 2020) combining climate modeling and the fossil record in search of clues to what led to all those earlier extinctions of our ancient ancestors suggests that climate change — the inability to adapt to either warming or cooling temperatures — likely played a major role in sealing their fate.

“Our findings show that despite technological innovations including the use of fire and refined stone tools, the formation of complex social networks, and — in the case of Neanderthals — even the production of glued spear points, fitted clothes, and a good amount of cultural and genetic exchange with Homo sapiens, past Homo species could not survive intense climate change,” says Pasquale Raia of Università di Napoli Federico II in Napoli, Italy. “They tried hard; they made for the warmest places in reach as the climate got cold, but at the end of the day, that wasn’t enough.”

To shed light on past extinctions of Homo species including H. habilis, H. ergaster, H. erectus, H. heidelbergensis, H. neanderthalensis, and H. sapiens, the researchers relied on a high-resolution past climate emulator, which provides temperature, rainfall, and other data over the last 5 million years. They also looked to an extensive fossil database spanning more than 2,750 archaeological records to model the evolution of Homo species’ climatic niche over time. The goal was to understand the climate preferences of those early humans and how they reacted to changes in climate.

Their studies offer robust evidence that three Homo species — H. erectus, H. heidelbergensis, and H. neanderthalensis — lost a significant portion of their climatic niche just before going extinct. They report that this reduction coincided with sharp, unfavorable changes in the global climate. In the case of Neanderthals, things were likely made even worse by competition with H. sapiens.

“We were surprised by the regularity of the effect of climate change,” Raia says. “It was crystal clear, for the extinct species and for them only, that climatic conditions were just too extreme just before extinction and only in that particular moment.” ...

FULL STORY:
https://scitechdaily.com/early-human-species-to-likely-driven-to-extinction-by-climate-change/

PUBLISHED REPORT:
https://www.cell.com/one-earth/fulltext/S2590-3322(20)30476-0
 
Newly published research indicates our earliest Homo sapiens ancestors in Africa lived longer ago than was previously believed.
The Earliest Unequivocal Evidence of Our Species May Be Even Older Than We Realized

Today, we still don't really know when or where the first Homo sapiens appeared on the scene, although an archaeological site in southwestern Ethiopia is one of our best lines of evidence. ...

To be clear, older remains attributed to Homo sapiens exist, dating back hundreds of thousands of years. But the line between us and our ancestors is a smear of characteristics, leaving us with the remains known as Omo I as a starting point for what is unequivocally modern.

The ancient bones of this long lost ancestor, named for the nearby Omo River, were buried with mollusk shells, which were, at the time, dated to about 130,000 years of age.

In the decades since, radioactive dating of the surrounding soil has allowed us to push back that age even further to about 200,000 years. And yet even that could be an underestimation.

A geochemical reanalysis of the archaeological site now suggests Omo I was squashed between two layers of volcanic ash, the upper layer of which was probably deposited in an eruption about 230,000 years ago. At the very least, researchers argue, Omo I must be even older than that.

"The fossils were found in a sequence, below a thick layer of volcanic ash that nobody had managed to date with radiometric techniques because the ash is too fine-grained," explains volcanologist Céline Vidal from Cambridge University. ...

The new estimate solidifies Omo I as the oldest unchallenged Homo sapiens in Africa. And while this suggests Ethiopia was a cradle for our species more than 230,000 years ago, other early humans were already using the continent as their nursery at this time.

In 2017, researchers announced they had found ancient human remains in Morocco that were dated between 280,000 years to 350,000 years of age.

The skulls found here are more elongated than ours today, with slightly larger teeth, which has led some scientists to suspect these were not Homo sapiens, but rather an 'archaic' species of human that spread to North Africa before our more direct ancestors arrived to replace them.

DNA analysis of these ancient Moroccan fossils has not been successful, which means we don't know how related they are to our own species.

An analysis of genes taken from the remains of a boy who lived just before migrations dramatically reshaped the genes of African populations several thousand years ago also hints at an ancient split of at least 260,000 years ago. ...

Judging from the fossil record, East Africa is an important hub for human evolution, but for all we know, there could be an even older human like us hiding somewhere else on the continent.

The hunt for our heritage continues. ...
FULL STORY: https://www.sciencealert.com/the-ea...-species-might-be-even-older-than-we-realized
 
Here are the bibliographic particulars and abstract from the published research report. The full report can be accessed at the link below.


Vidal, C.M., Lane, C.S., Asrat, A. et al.
Age of the oldest known Homo sapiens from eastern Africa.
Nature (2022).
https://doi.org/10.1038/s41586-021-04275-8

Abstract
Efforts to date the oldest modern human fossils in eastern Africa, from Omo-Kibish and Herto in Ethiopia, have drawn on a variety of chronometric evidence, including 40Ar/39Ar ages of stratigraphically associated tuffs. The ages that are generally reported for these fossils are around 197 thousand years (kyr) for the Kibish Omo I, and around 160–155 kyr for the Herto hominins. However, the stratigraphic relationships and tephra correlations that underpin these estimates have been challenged. Here we report geochemical analyses that link the Kamoya’s Hominid Site (KHS) Tuff, which conclusively overlies the member of the Omo-Kibish Formation that contains Omo I, with a major explosive eruption of Shala volcano in the Main Ethiopian Rift. By dating the proximal deposits of this eruption, we obtain a new minimum age for the Omo fossils of 233 ± 22 kyr. Contrary to previous arguments, we also show that the KHS Tuff does not correlate with another widespread tephra layer, the Waidedo Vitric Tuff, and therefore cannot anchor a minimum age for the Herto fossils. Shifting the age of the oldest known Homo sapiens fossils in eastern Africa to before around 200 thousand years ago is consistent with independent evidence for greater antiquity of the modern human lineage.

SOURCE / FULL REPORT: https://www.nature.com/articles/s41586-021-04275-8#citeas
 
Perhaps from an early failed human population.

Homo sapiens arrived in Southeast Asia as early as 86,000 years ago, a human shin bone fragment found deep within a cave in Laos reveals.

The finding comes from the cave of Tam Pà Ling, or Cave of the Monkeys, which sits at around 3,840 feet (1,170 meters) above sea level on a mountain in northern Laos. Human bone fragments previously found in the cave were 70,000 years old, making them some of the earliest evidence of humans in this area of the world. This discovery prompted archaeologists to dig deeper.

The team did just that, finding two new bones, they reported in a study published Tuesday (June 13) in the journal Nature Communications. The bones — fragments of the front of a skull and a shin bone — were likely washed into the Tam Pà Ling cave during a monsoon. Even though the bones were fractured and incomplete, the researchers were able to compare their dimensions and shape with other bones from early humans, finding that they most closely matched Homo sapiens rather than other archaic humans, such as Homo erectus, Neandertals or Denisovans.

https://www.livescience.com/archaeo...ve-hints-at-failed-population-from-prehistory
 
That was a close thing!

Nearly a million years ago, some devastating event nearly wiped out humanity's ancestors.

Genomic data from 3,154 modern humans suggests the population was reduced from approximately 100,000 to just 1,280 breeding individuals around 900,000 years ago. That's a jaw-dropping population decline of 98.7 percent that lasted 117,000 years and could have brought humanity to extinction.

The fact we're here today, and so numerous, is evidence that it wasn't. But the results, according to a team led by geneticists Haipeng Li of the Chinese Academy of Sciences and Yi-Hsuan Pan of East China Normal University in China, would explain a curious gap in the human fossil record in the Pleistocene.

"The gap in the African and Eurasian fossil records can be explained by this bottleneck in the Early Stone Age as chronologically," says anthropologist Giorgio Manzi of Sapienza University of Rome in Italy. "It coincides with this proposed time period of significant loss of fossil evidence."

population-bottlneck-diagram.jpg


A diagram describing the newly found bottleneck. (Science)


Population bottlenecks, as significant reductions in a group's numbers are known, are not uncommon. When a species is devastated by an event such as war, famine, or climate crisis, the resulting drop in genetic diversity can be traced through the progeny of the survivors. This is how we know that there was also a human population bottleneck in the Northern Hemisphere far more recently, some 7,000 years ago.

The further back in time you want to look, however, the more challenging it becomes to tease out a meaningful signal.

For this latest analysis, the research team developed a new method called the fast infinitesimal time coalescent process (FitCoal) to circumvent the accumulation of numerical errors usually associated with trying to unravel these past events.

https://www.sciencealert.com/our-genes-reveal-just-how-close-our-ancestors-came-to-extinction
 
There may have been a number of catastrophic events (such as tsunamis and flooding) that led to a die-off in animals that could be hunted.
I have the idea that the reduction in human population was caused by population fragmentation, as humanity's ancestors spread around the planet looking for hunting grounds. A low concentration of the population would mean that fewer babies were being born.
Once farming became an option, populations became more settled and led to a baby boom.
 
Perhaps from an early failed human population.

Homo sapiens arrived in Southeast Asia as early as 86,000 years ago, a human shin bone fragment found deep within a cave in Laos reveals.

The finding comes from the cave of Tam Pà Ling, or Cave of the Monkeys, which sits at around 3,840 feet (1,170 meters) above sea level on a mountain in northern Laos. Human bone fragments previously found in the cave were 70,000 years old, making them some of the earliest evidence of humans in this area of the world. This discovery prompted archaeologists to dig deeper.

The team did just that, finding two new bones, they reported in a study published Tuesday (June 13) in the journal Nature Communications. The bones — fragments of the front of a skull and a shin bone — were likely washed into the Tam Pà Ling cave during a monsoon. Even though the bones were fractured and incomplete, the researchers were able to compare their dimensions and shape with other bones from early humans, finding that they most closely matched Homo sapiens rather than other archaic humans, such as Homo erectus, Neandertals or Denisovans.

https://www.livescience.com/archaeo...ve-hints-at-failed-population-from-prehistory
And it's even more involved than what the scientists are constantly discovering.
For instance, I have the blood type B positive, which is one of the rarer types, and according to what I have read that blood type first appeared 15,000 years ago in the area of the Himalayan mountains.
So apparently even our different blood types evolved over many thousands of years, along with all these different types of humans.
 
That was a close thing!

Nearly a million years ago, some devastating event nearly wiped out humanity's ancestors.

Genomic data from 3,154 modern humans suggests the population was reduced from approximately 100,000 to just 1,280 breeding individuals around 900,000 years ago. That's a jaw-dropping population decline of 98.7 percent that lasted 117,000 years and could have brought humanity to extinction.

The fact we're here today, and so numerous, is evidence that it wasn't. But the results, according to a team led by geneticists Haipeng Li of the Chinese Academy of Sciences and Yi-Hsuan Pan of East China Normal University in China, would explain a curious gap in the human fossil record in the Pleistocene.

"The gap in the African and Eurasian fossil records can be explained by this bottleneck in the Early Stone Age as chronologically," says anthropologist Giorgio Manzi of Sapienza University of Rome in Italy. "It coincides with this proposed time period of significant loss of fossil evidence."

population-bottlneck-diagram.jpg


A diagram describing the newly found bottleneck. (Science)


Population bottlenecks, as significant reductions in a group's numbers are known, are not uncommon. When a species is devastated by an event such as war, famine, or climate crisis, the resulting drop in genetic diversity can be traced through the progeny of the survivors. This is how we know that there was also a human population bottleneck in the Northern Hemisphere far more recently, some 7,000 years ago.

The further back in time you want to look, however, the more challenging it becomes to tease out a meaningful signal.

For this latest analysis, the research team developed a new method called the fast infinitesimal time coalescent process (FitCoal) to circumvent the accumulation of numerical errors usually associated with trying to unravel these past events.

https://www.sciencealert.com/our-genes-reveal-just-how-close-our-ancestors-came-to-extinction

This narrative is challenged,

Could the lives of the eight billion people currently on Earth have depended on the resilience of just 1,280 human ancestors who very nearly went extinct 900,000 years ago?

That is the finding of a recent study which used genetic analysis modeling to determine that our ancestors teetered on the brink of annihilation for nearly 120,000 years.

However, scientists not involved in the research have criticized the claim, one telling AFP there was "pretty much unanimous" agreement among population geneticists that it was not convincing.

None denied that the ancestors of humans could have neared extinction at some point, in what is known as a population bottleneck.

But experts expressed doubts that the study could be so precise, given the extraordinarily complicated task of estimating population changes so long ago, and emphasized that similar methods had not spotted this massive population crash.

It is extremely difficult to extract DNA from the few fossils of human relatives dating from more than a couple of hundred thousand years ago, making it hard to know much about them.

But advances in genome sequencing mean that scientists are now able to analyze genetic mutations in modern humans, then use a computer model that works backwards in time to infer how populations changed—even in the distant past.

The study, published in the journal Science earlier this month, looked at the genomes of more than 3,150 modern-day humans.

The Chinese-led team of researchers developed a model to crunch the numbers, which found that the population of breeding human ancestors shrank to about 1,280 around 930,000 years ago.

https://phys.org/news/2023-09-skepticism-human-ancestors-extinct.html
 
The Woodworking Age: Homo heidelbergensis was handy as wekk.

Modified logs dating to about 476,000 years ago might be the oldest evidence of wooden structures, a new study finds.

Wooden artifacts decompose easily and are relatively scant in the archaeological record compared with stone or bone. The new finding, reported September 20 in Nature, suggests that the structural use of wood may stretch far back into the history of human ancestors, hinting at advanced cognitive skills and a less nomadic lifestyle for some hominids than previously thought.

“It’s a challenge to preconceptions about what are considered sophisticated, complex behaviors,” says Larry Barham, an archaeologist at the University of Liverpool in England. “For me, settling into one place and changing the landscape, that is very sophisticated.”

Humans and their ancestors have been using wood in some fashion for quite some time. The earliest known example of modified wood is a polished plank from Israel dating to around 780,000 years ago. Wooden tools don’t appear in the historical record until about 400,000 years ago. Before this new study, the earliest known example of a wooden structure was much more recent: around 9000 B.C.

During a dig in 2019, Barham and colleagues found five modified wooden objects in the exposed bank of a river flowing into the top of Kalambo Falls in Zambia. The area is rich with forest and has a consistently high water table. This makes it ideal for human habitation — and the water also blocks oxygen from buried wood. Since the 1950s, archaeologists have excavated ancient technologies here, though wooden objects couldn’t be accurately placed in time and clear modifications had been worn away.

This time the team used a technique known as luminescence dating (SN: 7/19/17). Minerals buried underground gradually absorb background radiation like a battery taking up charge, which can be released later as light. This reveals how many years ago a sample last saw the sun. The team analyzed 16 sand samples‚ including from directly around the wooden objects, and grouped the artifacts into three chunks of time from 476,000 to 324,000 years ago.

In the sands that are nearly half a million years old, the team found two large interlocking logs, with shaped ends and wide, carved notches at the point they overlap. Like an early version of Lincoln Logs, this would have held the wood together. Both logs showed evidence of chopping and scraping, and were buried near tools used for scraping or carving, hand axes and other crafting equipment.

A photo of two people examining an almost 480,000-year-old wooden log.


An ancient wooden artifact suggests early hominids living nearly half a million years ago may have shaped tree trunks into structures.LARRY BARHAM/UNIV. OF LIVERPOOL

These logs may have been part of a structure — a raised walkway, a place to store wood or somewhere to sit — that helped early hominids in their environment, the researchers suggest. Based on timing and location, the structure could be the handiwork of Homo heidelbergensis, a human ancestor that lived about 700,000 to 200,000 years ago. Other wooden objects recovered from the site include a wedge, a digging stick and a chopped log, dating from 390,000 to 324,000 years ago.

“This paper provides a wonderful peek into our past,” says Rebecca Biermann Gürbüz, a biological anthropologist at the University at Buffalo in New York who was not involved in the study. Other primates use wood and plants in a variety of ways, she says. “So the fact that [hominids] did so nearly half a million years ago is not surprising.”

In fact, Barham wonders if Stone Age is even the right term for that era. “Let’s say wood survived as much as bone does in the archaeological record,” he says. “Maybe we should relabel our Stone Age to the Woodworking Age, an Organic Age or something that reflects the reality of common behavior, which we can only really glimpse.” ...

https://www.sciencenews.org/article/logs-evidence-oldest-wood-structure
 
Hohle Fels Cave Yields Paleolithic Figurine Fragments


ivory-figurine-fragments.jpg


(M. Malina/University of Tübingen)
TÜBINGEN, GERMANY—Two fragments of a female figurine carved from mammoth ivory have been found in Hohle Fels Cave. The fragments resemble a breast and part of the stomach of the 40,000-year-old figurine known as the Venus from Hohle Fels, which was discovered in 2008. This carving may have been slightly larger, however, than the approximately two-inch-tall Venus. “The new discovery indicates that the female depictions are not as rare in the Aurignacian as previously thought, and that concerns about human sexuality, reproduction and fertility in general have a very long and rich history dating to the Ice Age,” Nicholas Conard of the University of Tübingen said in a press release. To read about another masterpiece of Paleolithic art, go to "New Life for Lion Man."

http://www.archaeology.org/news/3505-150722-ivory-figurine-fragments

Might be a tool rather than art.

A pair of historians at the University of Tübingen have found evidence that an ancient baton, thought to be a work of art created by early humans thousands of years ago, is actually a device to assist with making rope. In their study, published in the journal Science Advances, Nicholas Conard and Veerle Rots created a replica of the baton and found that it could easily be used to make rope.

In 2015, multiple pieces of ivory were discovered in a cave in Germany's Hohle Fels, all of which showed signs of workmanship. Dating of the pieces showed they had been fashioned approximately 37,000 years ago, likely by modern humans. Since that time, researchers have believed the ivory pieces were fashioned from a mammoth tusk as works of art. In this new study, the researchers found evidence that at least one of them was instead a baton carved in a way that eased the task of making rope.

Prior research has shown that early humans were making rope thousands of years ago, and were living in the part of Germany where the batons were found. One of the pieces, a baton approximately 21 cm long, looked to the researchers like a modern cricket bat with four holes carved through its flattest part.

Working on a hunch, the researchers studied the baton and found wear on the edges of the holes, along with groves, indicating that something had been repeatedly pulled through them. Residue on the hole walls suggested that it was some sort of plant material. ...

https://phys.org/news/2024-02-ancient-holed-ivory-baton-rope.html


 
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