origin of humans (Origins)

by dhw, Friday, April 14, 2023, 11:59 (373 days ago)

An article in today’s Times contains an extraordinary contradiction.The headline is:
Grassland theory uproots story of our first steps.

Researchers in East Africa have shown that on 9 sites a group of plants known as C4 grasses were an important part of the ecosystem about 21 million years ago, which “suggests that substantial areas of open grassland existed at least ten million years earlier than was thought.” This in turn suggests that Morotopithecus – an ape that lived then and is “regarded as one of the best representatives of the ancestors to all of the living apes and humans”- would have lived in open spaces. And this is where the article contradicts itself. It begins with the following:

It was widely thought that ancient apes first adopted a vertical posture while living high in the canopies of dense forests, where the limbs of the tree would have met those of the next. Being upright, it was reasoned, would have made it easier for these animals to climb and to reach for fruit while balancing on branches. It was thought that only rarely, if ever, would they have set foot on the ground.

But after explaining all the research, the article goes on to say: “Roughly speaking, researchers have often assumed that humans came to walk on two legs because dense forests receded and grassland environments opened up. Being upright would have allowed us to see for relatively large distances across a flat savannah and would have given us an efficient running gait. However, the idea that ‘shrinking forests made us human’ seems too simplistic.”

I didn’t know researchers had "widely thought" or "often assumed" both theories at the same time! It’s the latter that I think has held sway and certainly sounds to me far more convincing than the former, since even in dense forests, ancient apes would have continued to move through the trees as they do now. And I can see nothing in the new research that makes it sound “too simplistic”. The new research need not even change our views on the timetable of events. Morotopithecus “would not have walked on two legs like a human”, so it proves nothing about the timing of bipedalism. We should bear in mind that bipedalism could have originated in a single group of anthropoids. The researchers examined nine sites. How many sites would have to be explored in order to find what may have been the single original site where a shrinking forest gave way to grassland, and a single group of anthropoids adjusted to their new surroundings by standing upright? Convergent evolution might have resulted in more than one group making the same adjustments, but this still wouldn’t invalidate the second theory.

origin of humans

by David Turell @, Friday, May 05, 2023, 20:36 (352 days ago) @ dhw

dhw: An article in today’s Times contains an extraordinary contradiction.The headline is:
Grassland theory uproots story of our first steps.

Researchers in East Africa have shown that on 9 sites a group of plants known as C4 grasses were an important part of the ecosystem about 21 million years ago, which “suggests that substantial areas of open grassland existed at least ten million years earlier than was thought.” This in turn suggests that Morotopithecus – an ape that lived then and is “regarded as one of the best representatives of the ancestors to all of the living apes and humans”- would have lived in open spaces. And this is where the article contradicts itself. It begins with the following:

It was widely thought that ancient apes first adopted a vertical posture while living high in the canopies of dense forests, where the limbs of the tree would have met those of the next. Being upright, it was reasoned, would have made it easier for these animals to climb and to reach for fruit while balancing on branches. It was thought that only rarely, if ever, would they have set foot on the ground.

But after explaining all the research, the article goes on to say: “Roughly speaking, researchers have often assumed that humans came to walk on two legs because dense forests receded and grassland environments opened up. Being upright would have allowed us to see for relatively large distances across a flat savannah and would have given us an efficient running gait. However, the idea that ‘shrinking forests made us human’ seems too simplistic.”

I didn’t know researchers had "widely thought" or "often assumed" both theories at the same time! It’s the latter that I think has held sway and certainly sounds to me far more convincing than the former, since even in dense forests, ancient apes would have continued to move through the trees as they do now. And I can see nothing in the new research that makes it sound “too simplistic”. The new research need not even change our views on the timetable of events. Morotopithecus “would not have walked on two legs like a human”, so it proves nothing about the timing of bipedalism. We should bear in mind that bipedalism could have originated in a single group of anthropoids. The researchers examined nine sites. How many sites would have to be explored in order to find what may have been the single original site where a shrinking forest gave way to grassland, and a single group of anthropoids adjusted to their new surroundings by standing upright? Convergent evolution might have resulted in more than one group making the same adjustments, but this still wouldn’t invalidate the second theory.

All Darwinist suppositions are simplistic. Apes are not generally upright. They walk on their knuckles quite constantly and become upright on occasion. Their pelvis is not built for bipedalism, like ours. Based on fossils like Lucy, bipedalism came with a slightly enhanced brain, which then went on to tremendous enhancement far beyond the needs of early ape Men. All natural suppositions are far, far to simplistic to explain the changes.

origin of humans; a new fourth branch

by David Turell @, Monday, August 07, 2023, 15:39 (258 days ago) @ David Turell

Found in China:

https://www.sciencealert.com/ancient-skull-found-in-china-is-unlike-any-human-seen-befo...

"An international team of scientists has described an ancient human fossil in China unlike any other hominin found before.

"It resembles neither the lineage that split to form Neanderthals, nor Denisovans, nor us, suggesting our current version of the human family tree needs another branch.

"The jaw, skull, and leg bones belonging to this yet-to-be classified human, labeled HLD 6, were discovered in Hualongdong, in East Asia, in 2019. In the years since, experts at the Chinese Academy of Sciences (CAS) have struggled to match the remains to a known lineage.

"The hominin's face is similarly structured to that of the modern human lineage, which split from Homo erectus as far back as 750,000 years ago. But the individual's lack of chin appears more like that of a Denisovan – an extinct species of ancient human in Asia that split from Neanderthals more than 400,000 years ago.

***

"Historically, many hominin fossils from the Pleistocene that have been found in China haven't fitted easily into any one lineage. As a result, such remains are often explained away as intermediate variations on a straight path to modern humanity; as an archaic example of a Homo sapien, for example, or an advanced form of Homo erectus.

"But this rather linear, simplistic interpretation is controversial and not widely accepted. While Homo erectus did persist in Indonesia until roughly 100,000 years ago, the remains that were recently found in East China hold a greater resemblance to other, more modern lineages of hominin.

"Previously, genome studies on Neanderthal remains in Europe and western Asia have found evidence of a fourth lineage of hominin living in the Middle to Late Pleistocene.

"But this missing group has never been officially identified in the fossil record.

***

"The fossilized jaw and skull belong to a 12- or 13-year-old, and while its face has modern-human like features, the limbs, skull cap, and jaw "seem to reflect more primitive traits," the authors of the analysis write.

"Their results complicate the path to modern humans. The mosaic of physical features found in this ancient hominin instead supports the coexistence of three lineages in Asia – the lineage of H. erectus, the lineage of Denisovan, and this other lineage that is "phylogenetically close" to us.

"Homo sapiens only appeared in China around 120,000 years ago, but it seems as though some of our 'modern' features existed here long before that. It may be that the last common ancestor of H. sapiens and Neanderthals arose in southwest Asia and later spread to all continents."

Comment: the Moroccan sapiens fossil dated at 315,000 years ago complicates the issue.

origin of humans; theory of hair loss

by David Turell @, Thursday, August 17, 2023, 22:21 (248 days ago) @ David Turell

Pure theory, but th physiological changes are enormous:

https://www.the-scientist.com/ts-digest/issue/the-roles-of-endogenous-psychedelics-18-2...

:Luscious fur coats insulate many animals from the cold and protect them from sunlight, insects, and sharp objects in their environments. Yet, somehow humans evolved to be relatively hairless. While this may appear to be a case of selection against a highly desirable trait, Nina Jablonski, who studies the evolution of human skin and skin pigmentation at Pennsylvania State University, said that our relative hairlessness arose just like other traits did: it offered evolutionary advantages.

:The origins of human hairlessness began nearly two million years ago, driven by environmental changes in locations where human ancestors lived. As wooded landscapes in equatorial Africa gave way to open grassland areas, human ancestors had to spend more time outdoors to find food and water. For walking and running long distances, early members of the genus Homo developed a modern human skeleton with long legs and shorter arms. “Around this time, humans lost most of their body hair,” said Jablonski.

"Shedding body hair was a key adaptation since, unlike most other mammals, primates lack a key mechanism for cooling the blood around the brain when it’s hot outside or after exercise. This means that the temperature of the brain increases when the body heats up, which can affect brain functions. Evolution of human hairlessness was accompanied by the Luscious fur coats insulate many animals from the cold and protect them from sunlight, insects, and sharp objects in their environments. Yet, somehow humans evolved to be relatively hairless. While this may appear to be a case of selection against a highly desirable trait, Nina Jablonski, who studies the evolution of human skin and skin pigmentation at Pennsylvania State University, said that our relative hairlessness arose just like other traits did: it offered evolutionary advantages.

"The origins of human hairlessness began nearly two million years ago, driven by environmental changes in locations where human ancestors lived. As wooded landscapes in equatorial Africa gave way to open grassland areas, human ancestors had to spend more time outdoors to find food and water. For walking and running long distances, early members of the genus Homo developed a modern human skeleton with long legs and shorter arms. “Around this time, humans lost most of their body hair,” said Jablonski.

"Shedding body hair was a key adaptation since, unlike most other mammals, primates lack a key mechanism for cooling the blood around the brain when it’s hot outside or after exercise. This means that the temperature of the brain increases when the body heats up, which can affect brain functions. Evolution of human hairlessness was accompanied by the Luscious fur coats insulate many animals from the cold and protect them from sunlight, insects, and sharp objects in their environments. Yet, somehow humans evolved to be relatively hairless. While this may appear to be a case of selection against a highly desirable trait, Nina Jablonski, who studies the evolution of human skin and skin pigmentation at Pennsylvania State University, said that our relative hairlessness arose just like other traits did: it offered evolutionary advantages.

"The origins of human hairlessness began nearly two million years ago, driven by environmental changes in locations where human ancestors lived. As wooded landscapes in equatorial Africa gave way to open grassland areas, human ancestors had to spend more time outdoors to find food and water. For walking and running long distances, early members of the genus Homo developed a modern human skeleton with long legs and shorter arms. “Around this time, humans lost most of their body hair,” said Jablonski.

"Shedding body hair was a key adaptation since, unlike most other mammals, primates lack a key mechanism for cooling the blood around the brain when it’s hot outside or after exercise. This means that the temperature of the brain increases when the body heats up, which can affect brain functions. Evolution of human hairlessness was accompanied by the development of more sweat glands and darker skin pigmentation. Sweat glands helped them dissipate heat from the skin more effectively, while darker skin pigmentation protected their mostly hairless skin from the damaging effects of solar radiation.

"According to Jablonski, the idea of whole-body cooling and heating, or thermoregulation, seems like the most likely explanation for human hairlessness based on physical evidence and our knowledge of comparative anatomy and physiology. “We were shooting in the dark decades ago. Now, we can be much, much clearer on what the likely courses of evolution were,” she said."

Comment: she is so backward in her proposal. Losing hair required all the other changes. They all had to occur together in a coordinated way by design. The hair didn't just fall out; so much more was done as the article shows.

origin of humans; a new ape ancestor

by David Turell @, Wednesday, August 23, 2023, 17:59 (242 days ago) @ David Turell

Found in Turkey:

https://www.nature.com/articles/s42003-023-05210-5

"Fossil apes from the eastern Mediterranean are central to the debate on African ape and human (hominine) origins. Current research places them either as hominines, as hominins (humans and our fossil relatives) or as stem hominids, no more closely related to hominines than to pongines (orangutans and their fossil relatives). Here we show, based on our analysis of a newly identified genus, Anadoluvius, from the 8.7 Ma site of Çorakyerler in central Anatolia, that Mediterranean fossil apes are diverse, and are part of the first known radiation of early members of the hominines. The members of this radiation are currently only identified in Europe and Anatolia; generally accepted hominins are only found in Africa from the late Miocene until the Pleistocene. Hominines may have originated in Eurasia during the late Miocene, or they may have dispersed into Eurasia from an unknown African ancestor. The diversity of hominines in Eurasia suggests an in situ origin but does not exclude a dispersal hypothesis.

"The origin of the hominines is among the most hotly debated topics in paleoanthropology. The traditional view, ever since Darwin, holds that hominines and hominins originate in Africa, where the earliest hominins are found and where all extant non-human hominines live. More recently a European origin has been proposed, based on the phylogenetic analysis of late Miocene apes from Europe and Central Anatolia1. The fossils described here attest to a lengthy history of hominines in Europe, with multiple taxa in the eastern Mediterranean known for at least. Our phylogenetic analysis, based on the new specimens described here and a large sample of other fossil and extant hominoids, Our most parsimonious phylogenetic results suggest that hominines in the eastern Mediterranean evolved from dryopithecins in central and western Europe, though there are alternative interpretations. Either way, the oldest known hominines are European. They may have dispersed into Europe from ancestors in Africa, only to become extinct. However, the more likely and more parsimonious interpretation is that hominines evolved over a lengthy period in Europe and dispersed into Africa before 7 Ma.

***

"...the sample of ape fossils from Çorakyerler demonstrates that great ape diversity in the eastern Mediterranean is greater than previously believed and that hominines had diversified into multiple taxa long before their first documented appearance in Africa."

Comment: what is of interest is that apes, prior to hominin appearance were all over Europe and may not have been in Africa, not as I previously thought.

origin of humans; early use of wood

by David Turell @, Wednesday, September 20, 2023, 18:11 (214 days ago) @ David Turell

Half a million years ago:

https://www.sciencealert.com/evidence-of-a-wooden-structure-that-predates-our-species-u...

"Uncovered in 2019 at the Kalambo Falls in Zambia, the objects provide archaeologists with an exceptionally rare look at wooden technology from mid-Paleolithic Africa, a time better known for an acceleration in the innovations of stone tools. The logs also predate the evolution of our own species, Homo sapiens.

"An analysis conducted by an international team of researchers has now come to the astonishing conclusion that the wooden artifacts were once part of a permanent structure of some kind, such as a platform or building.

"If so, the discovery complicates the conventional image of hominins as nomads hunting migrating herds or gathering seasonal flora with relatively basic tools.

"'This find has changed how I think about our early ancestors," says University of Liverpool archaeologist Larry Barham, leader of a project researching Stone Age technology called Deep Roots of Humanity.

"'Forget the label 'Stone Age,' look at what these people were doing: they made something new, and large, from wood. They used their intelligence, imagination, and skills to create something they'd never seen before, something that had never previously existed." (my bold)

"While indirect signs of woodworking by mid-Pleistocene hominins can be found in the form of plant residue or patterns of wear on stone tools, Stone Age items carved from timber rarely survive the ages.

"At nearly 800 thousand years old, a solitary plank with a polished surface found in Israel is the current record holder for world's earliest prime example of carpentry.

***

"While it's impossible to determine the purpose of the interlocking sections, viewed in association with other discoveries at the site, including several other small wooden artifacts and stone implements, the authors tentatively interpret the findings as structural.

"To determine when the items may have been crafted, the researchers applied a version of infrared stimulated luminescence dating to determine when minerals called feldspar in the surrounding sediment were last bathed in sunlight.

"That figure, of just under 450 to 500 thousand years ago, puts the construction well before the era in which our own species is believed to have emerged.

"To take the time and effort to construct large, wooden items that can't be easily transported, we might presume the structure's makers would be relatively settled in one place, or at least frequent visitors.

"'They transformed their surroundings to make life easier, even if it was only by making a platform to sit on by the river to do their daily chores. These folks were more like us than we thought," says Barham.

"With its perennial waters, lush greenery, and stunning views, it's not hard to see why our ancestors kept coming back to the falls at Kalambo River since long before we were even human."

Comment: could these folks be Erectus? And quite advanced for primarily stone age. Note my bold. They had a very competant brain.

origin of humans; evolution of the skull

by David Turell @, Thursday, October 12, 2023, 18:08 (192 days ago) @ David Turell

Started with a fish 450 million year ago:

https://www.discovermagazine.com/the-sciences/ancient-fish-head-fills-a-100-million-yea...

"This 455-million-year-old specimen of Eriptychius americanus contains the earliest ever seen neurocranium — the cartilage protecting the fish’s brain — and one of the strangest. According to the study, the fish’s cartilage fits neatly yet loosely around the brain in a design with no known analogue.

"As the earliest vertebrate neurocranium ever studied, it fills a 100-year gap between the earliest such fossils ever recovered previously (from about 400 million years ago) and the origin of vertebrate fish some 500 million years ago.

"One of the greatest innovations of the vertebrate body plan, the neurocranium both protects the brain and helps to connect it to sensory organs, the mouth and more. In humans, the neurocranium is the portion of the skull that contains the brain, and the skull's seam-like sutures allow it to expand all the way until early adulthood to allow for growth.

"While the human skull is composed of 22 different bony pieces, E. americanus’ neurocranium was composed of 10 long pieces of cartilage that fit together without being fused, according to the X-ray scans. The imaging also revealed that canals snaked through the cartilage to deliver either blood supply or connections to sensory organs. The fish’s skin wrapped tightly around the whole structure, though the scientists noted a clear anatomical distinction between the two.

"This novel neurocranium falls somewhere between the loose, open cartilage style seen with lampreys and the more closed-off designs present in gnathosomes, a group that includes humans.

"Vertebrates exist with both structures, and scientists have tried to determine how they evolved. The new paper speculates that the largely locked-up cranium we enjoy evolved later down the line from E. americanus.

"Ultimately, that layout became a central part of gnathosomes as we know them (and us) today.

“'These are tremendously exciting results that may reveal the early evolutionary history of how primitive vertebrates protected their brains,” said Ivan Sansom, a paleobiologist."

Comment: the brain is so important it must have a protective casing. How did an unguided evolution have the foresight to recognize the potential dangers to a soft brain? This shows the purposeful design a designer would follow. When studying evolution, it is always important to ask why and how this new event happened. Look for purpose and you will see design.

origin of humans; Erectus in Ethiopian highlands

by David Turell @, Friday, October 13, 2023, 20:29 (191 days ago) @ David Turell

Two million years ago:

https://www.newscientist.com/article/2397291-early-humans-lived-in-ethiopian-highlands-...


"Ancient humans were living in the highlands of what is now Ethiopia as early as 2 million years ago. A reanalysis of a fossilised jawbone from the region confirms that it belonged to a Homo erectus, and represents the earliest evidence of hominins living in such high-altitude areas.

"The highlands represent “a third pole for human evolution in Africa”, says Margherita Mussi of the Italo-Spanish Archaeological Mission at Melka Kunture and Balchit, based in Rome. Hominins have been found in large numbers in eastern and southern Africa, but not to date in upland areas.

***

"Mussi and her team used synchrotron imaging to study Little Garba’s teeth, which hadn’t yet erupted from the jawbone. They compared the shape of the teeth to those of multiple hominin species. “The teeth are a very good marker, so we can say for sure this is indeed an early Homo erectus,” says Mussi.

"In a previous study published in 2021, Mussi’s team also re-dated the Garba IV site. It consists of layers of sediment laid down over time. In the sediments, the researchers found traces of past shifts in Earth’s magnetic field, which could be matched to similar records elsewhere. Based on this, they conclude that Little Garba is 2 million years old. This makes it one of the oldest H. erectus ever found.

***

"Furthermore, the researchers re-examined the stone tools found in the sediments at Garba IV. They say there is a transition from older and simpler Oldowan tools to more sophisticated Acheulean tools between 2 and 1.95 million years ago. The Acheulean tools were harder to make because they required careful planning, but they opened up a wider range of foods.

"Putting these lines of evidence together, Mussi argues that the H. erectus population had to adapt to conditions in the highlands, and developed new styles of stone tools to do so."

Comment: H. erectus is our direct ancestor. They spread all over the Eastern hemisphere and undoubtedly coexisted with early H. sapiens

origin of humans; early sapiens Neanderthal mix

by David Turell @, Tuesday, October 24, 2023, 17:30 (180 days ago) @ David Turell

Not just in Europe:

https://www.sciencealert.com/unknown-human-lineage-found-buried-in-the-neanderthal-geno...

"As Homo sapiens migrated into Eurasia more than 70,000 years ago, much of the continent was already inhabited by Neanderthals, hominins who shared an ancestor with us but had spent roughly half a million years diverging.

***

"During their Late Pleistocene overlap in Eurasia, however, we know the two hominin species sometimes interbred, since many humans today still have traces of Neanderthal DNA.

"And according to a new study, this relationship goes back even farther than we thought, with a long-forgotten earlier chapter re-emerging from clues in the Neanderthal genome.

"When modern humans reached Eurasia in the Late Pleistocene, the study suggests, Neanderthals living there already carried traces of our species' DNA, apparently from a much older, previously unknown run-in with an even more ancient lineage of anatomically modern humans.

"That would mean some Homo sapiens ventured into Eurasia more than 250,000 years ago, the study's authors report, long before the continent's earliest evidence of modern humans. For context, the fossil record indicates our species evolved in Africa only 300,000 years ago.

"'We found this reflection of ancient interbreeding where genes flowed from ancient modern humans into Neanderthals," says Alexander Platt, an evolutionary biologist at the University of Pennsylvania.

"'This group of individuals left Africa between 250,000 and 270,000 years ago. They were sort of the cousins to all humans alive today, and they were much more like us than Neanderthals," Platt says.

"The early modern humans who made it to Eurasia later died out, the researchers note, and Neanderthals continued to dominate the continent for another 200,000 years or so. Hidden in the Neanderthal genome, however, were remnants from this ancient encounter.

"To reveal this, the study's authors first followed clues uncovered by another recent study, which found Neanderthal-like chunks of DNA – called Neanderthal-homologous regions (NHRs) – in multiple present-day human populations from Africa.

"This was surprising, since most interbreeding between modern humans and Neanderthals likely happened in Eurasia. It raised questions about how Neanderthal DNA, typically associated with Eurasian ancestry, could be seemingly abundant in Africa.

***

"NHRs were found in every population tested, showing they are widespread in Africa. Most of this 'Neanderthal-like' DNA originated not with Neanderthals, however, but with ancient modern humans who migrated from Africa to Eurasia about 250,000 years ago.

"As the newcomers interbred with Neanderthals, they left a legacy: Up to 6 percent of the Neanderthal genome came from early members of our species, the researchers report.

"The study also found evidence that, in certain populations, Neanderthal genes were introduced by people migrating back to Africa from Eurasia, where their ancestors had presumably interbred with Neanderthals."

Comment: Lot's more intermixing/interbreeding than realized. Sapiens were obviously prone to migration looking for the best area to live.

origin of humans; migration to Asia controlled by climate

by David Turell @, Tuesday, January 09, 2024, 16:07 (103 days ago) @ David Turell

About 100,000 years ago as climate changed:

https://mail.google.com/mail/u/0/#inbox/FMfcgzGwJchvfjLhvTTCjpkhmdChWdGc

"Our species evolved in Africa some 300,000 years ago, but fossil evidence suggests people didn't begin migrating into East Asia until around 100,000 years ago. What took them so long? A new analysis of ancient climate conditions suggests these eastbound migrants had to wait until a strengthening monsoon pattern across southern Asia rolled out a green carpet for them.

"Before about 125,000 years ago, people journeying east out of the African continent would have encountered cold, arid conditions inhospitable to modern humans. But then, a lot changed—including greenhouse gas concentrations, the volume of ice covering the Northern Hemisphere, and the intensity of sunlight reaching Earth, ultimately governed by the planet’s tilt, wobble, and solar orbit. Combined, these increased heat and rainfall across the region, and this new climate produced a green corridor, the authors argue, that would have proven irresistible to hunter-gatherers at the time, drawing them into East Asia.

“'Now we can confidently add rain and water to the equation that makes environment more suitable for H. sapiens settlement,” says anthropologist and study author María Martinón-Torres."

From the original article:

https://www.science.org/content/article/strong-monsoons-may-have-carved-path-early-huma...

"Evidence from fossils, artifacts, and DNA has established that H. sapiens evolved in Africa by roughly 300,000 years ago. About 60,000 years ago, the lineage that led to people alive today began to disperse across all of Earth’s habitable lands. But remains that resemble H. sapiens, reportedly dated to between 120,000 and 70,000 years old, have surfaced at various East Asian sites, including Fuyan Cave in China and Tam Pà Ling in Laos. Those putative modern human groups may not have persisted, and anthropologists debate what drove them to venture out in the first place.

***

"A team led by Chinese Academy of Sciences geologist Hong Ao sought a record that could track the timing of these changes on a scale of centuries. In 2021, they found what they were looking for: a slope of the Chinese Loess Plateau where windblown sediment had accumulated relatively quickly, creating a high-resolution record. For 1 month, the researchers dug steps into the plateau and shoveled sediments about every 2 centimeters along a 44-meter slope. From 2066 samples, they measured magnetic particles that form more abundantly as wetter conditions hasten the formation of soils with iron minerals. This provided snapshots of monsoon intensity every 100 to 800 years for the past 280,000 years.

"The researchers combined this record with a climate simulation model and existing environmental reconstructions to make estimates for annual rainfall, summer temperature, and other climate variables.

***

"How wet Asia gets, the researchers learned, varies with multiple factors, including greenhouse gas concentrations, the amount of ice covering the Northern Hemisphere, and the intensity of sunlight reaching Earth, ultimately governed by the planet’s tilt, wobble, and solar orbit. Between 125,000 and 70,000 years ago, when H. sapiens likely apparently first ventured there, East Asia had spells of 27.5°C summers with more rain than the present day—an enticing environment for mammals and the hunter-gatherers tracking them.

“'Now we can confidently add rain and water to the equation that makes environment more suitable for H. sapiens settlement,” says study author María Martinón-Torres, an anthropologist with Spain’s National Research Center on Human Evolution."

Comment: H. erectus was certainly prone to migration, always looking for the best spots to live. This theory does not explain the thinking that North America was colonized across an ice bridge to Alaska. Not a hospitable climate in that instance.

origin of humans; migration to the Americas

by David Turell @, Wednesday, January 10, 2024, 21:32 (102 days ago) @ David Turell

Much earlier than previously known:

https://www.smithsonianmag.com/smithsonian-institution/thirteen-discoveries-made-about-...

"...tool use doesn’t have to be confined to purely practical purposes. Modern human cultural expression is characterized by the production and aesthetic significance of jewelry, clothing and other items. Two stories from this year use jewelry and personal adornments specifically to better unravel the story of human migration and existence.

"First, a study published in July by Thais Pansani and colleagues investigates the remains of giant sloths from Santa Elina in central Brazil. At this site, abundant stone tools are intermixed with the fossils of the extinct ground sloth Glossotherium phoenesis, which grew to be 10 to 13 feet long and weighed 1.1 to 1.6 tons. These fossils include thousands of osteoderms, bony plates in the sloth’s skin similar to the armor on an armadillo, to whom sloths are closely related.

"Strikingly, three of these osteoderms had holes drilled into them by humans, which, according to the authors, means they were fashioned into pendants to be worn. These drill holes were also made prior to the bones becoming fossilized, meaning that humans must have existed alongside these megafauna to have access to their fresh bones.

"The dating of the oldest human activity at this site, including these giant sloth bone pendants, to around 27,000 years ago means that modern humans reached central Brazil prior to the last glacial maximum around 20,000 years ago. This study contributes to the growing body of evidence demonstrating that modern human migration into the Americas is much older than previously accepted."

Comment: migration was certainly Eastward. The date of 20,000 year ago for the last glaciation means a so-called ice-bridge existed, but recognizing how humans sailed around the Pacific, my bet is they sailed to South America at these much earlier times.

origin of humans; migration to Europe

by David Turell @, Thursday, February 01, 2024, 15:32 (80 days ago) @ David Turell

Specific tools found from before 35,000 years ago:

https://www.science.org/content/article/puzzling-prehistoric-artifacts-served-practical...

"In 2015, archaeologists working at a cave in southwestern Germany found an enigmatic perforated baton in a cave called Hohle Fels. It was a near-perfect match for an artifact found in 1983 in a cave down the road. Carved from single pieces of mammoth ivory, the Hohle Fels baton—roughly 20 centimeters long, about the length of a large paperback book—had multiple holes with spiraling grooves around the openings.

"Similar objects have been found elsewhere in Germany and in nearby France, often made from ivory or antler. They date from the last ice age, more than 35,000 years ago, a time when human hunters and foragers were flourishing across Europe and creating cave paintings, figurines, and other expressions of creativity. In the past, many archaeologists interpreted these batons as a noisemaker or ritual object, a sort of ice age magic wand or scepter. “Ritualism was something they used to ascribe everything to,” says Wei Chu, an archaeologist at Leiden University.

"In a new paper out today in Science Advances, researchers suggest the tools were used for a more prosaic purpose: to make rope.

***

"After removing tiny bits of soil near the holes, Veerle Rots, an archaeologist at the University of Liège and co-author of the new research, peered at their edges under a microscope and found tiny plant in much higher concentrations than in the surrounding soil. “The combination of looking at it, seeing the grooves were intentionally made, and finding those fibers made us think it was a tool” used for turning plant fiber into rope, Rots says.

"Although perishable items such as fabric and cord haven’t survived the millennia, hunter-gatherers couldn’t have survived without them. Twine, cord, and rope were needed for a host of tasks, including fastening stone points to spears, tying down tents, and securing packages of meat. “Cords are very important in people’s lives, but we hardly ever have traces of them,” Rots says. “This tool permitted us to reflect on the whole process.”

"Once the researchers had a hypothesis, they set out to test it. An expert carver recreated copies of the baton, first out of wood and then—because mammoth ivory was difficult to come by—the tusk of an African warthog.

"The team next turned to historic depictions of ropemaking. In the Middle Ages, ropemakers used blocks of wood with similar-size drilled holes. By pulling fibers through adjacent holes, artisans working in teams of three or four were able to maintain tension on the fibers while braiding them into multistrand ropes. With a little practice, the archaeologists found their replica tool “works very efficiently and quickly to make thick cords with very little effort,” Rots says.

"The researchers managed to fashion 5 meters of rope in about 10 minutes with their replica batons. For fiber, they used everything from flax and hemp to cattail reeds—all plants that would have grown near the Hohle Fels and Geissenklösterle caves 30,000 years ago. The ropes proved capable of supporting the weight of one of the team’s larger members. Reeds made the strongest rope fiber.

***

"The find is more evidence the “cave man” designation applied to people in the past underestimates their innovative capacities. “People back then weren’t stupid,” Conard says. “They knew how to do all kinds of things.'”

Comment: the illustrations show the actual process. The final paragraph says it all. H. sapiens were bright folks.

origin of humans; migration to Europe

by David Turell @, Thursday, February 01, 2024, 15:50 (80 days ago) @ David Turell

Around 45,000 year ago:

https://www.science.org/content/article/mysterious-ice-age-artifacts-suggest-modern-hum...

"More than 45,000 years ago, small bands of hunters chased horses, reindeer, and mammoth over a vast expanse of tundra that stretched across most of northern Europe. They rarely stayed anywhere for long, leaving behind a scattering of stone tools and traces of the odd campfire in the depths of caves.

"For more than a century, archaeologists debated whether these artifacts were left by some of the last Neanderthals to roam Europe—or the first modern humans to brave the northern reaches of the continent.

"A trio of papers published today in Nature and Nature Ecology & Evolution may help settle the question. Between 2016 and 2022, archaeologists recovered fragments of hominin bone from a cave in the central German village of Ranis. The bones were at least 45,000 years old, and their DNA has now identified them as the remains of our species. “We now have a Homo sapiens population in northern Europe long before Neanderthals disappeared,” says Marcel Weiss, an archaeologist at the Friedrich Alexander University of Erlangen-Nuremberg who supervised the excavations.

"What’s more, the bones were found with a type of stone blade known from other sites across northern Europe, from the British Isles to modern-day Poland. Archaeologists once assumed they were the handiwork of Neanderthals, but the Ranis bones hint that the tools—a style called Lincombian-Ranisian-Jerzmanowician (LRJ)—are modern humans’ calling card. “This suggests that early humans were far more widely spread, much earlier than we thought,” says University of Vienna archaeological scientist Tom Higham, who was not involved with the research. “What seems to be emerging is a complex mosaic pattern” in northern Europe, with pioneering bands of modern humans sharing the continent with Neanderthals.

"The Ranis bones aren’t the only evidence for H. sapiens’s early presence in Europe: In 2022, members of the same team reported finding 45,000-year-old modern human remains at a cave in Bulgaria called Bacho Kiro. A woman’s skull reported last year from Zlatý kůň, a site in the Czech Republic, had well-preserved modern human DNA and may be more than 43,000 years old. Another team has claimed still older H. sapiens finds—including a tooth from a cave in southern France that may be 54,000 years old.

***

"The new evidence from Ranis, added to Bacho Kiro and Zlatý kůň suggests that rather than a single wave, small groups of modern humans moved from Africa into Europe piecemeal starting about 48,000 years ago, overlapping with Neanderthals for many millennia. “That implies coexistence and competition and interaction. It’s a much more complex and diverse process,” says Carles Lalueza-Fox, an archaeologist who now directs the Museum of Natural Sciences of Barcelona and was not part of the research team.

"Genetic evidence has confirmed that the two groups sometimes met and interacted. DNA results from Bacho Kiro, for example, showed that people there had Neanderthal ancestors within six generations, although the Zlatý kůň woman had no recent Neanderthal ancestry. Analysis of the genetic results from the Ranis individuals is ongoing, but early results hint at the mobility of these small bands, showing close connections to the skull found at Zlatý kůň, more than 500 kilometers to the south.

***

"Oxygen isotopes from horse teeth in the cave’s LRJ layers, for example, captured a hyperlocal weather report from 48,000 years ago. The average forecast? What researchers call “peri-Arctic,” or 7°C to 15°C colder than modern-day Germany. “These guys spread in a very hostile environment, like the north of Scandinavia today,” says Jean-Jacques Hublin, a paleoanthropologist at the College of France who led the Ranis research.

***

"Though they apparently managed to make a go of it for millennia, ultimately the Ranis people and their contemporaries “weren’t entirely successful,” Hublin says. “They didn’t replace the Neanderthals living farther south, and at least when we try to trace the descendants of people of this time, from Bacho Kiro, it seems we have very little of their genome in later populations.” About 40,000 years ago, a new wave of modern humans arrived and proliferated on a much larger scale. It was those people who soon pushed Neanderthals to the margins, and then to extinction."

Comment: we are seeing a gradual exposition of how sapiens arrived and took over Europe at very cold times. The issue becomes what made them leave warmer climates? Were they forced to?

origin of humans; early migration to Jordan

by David Turell @, Friday, February 09, 2024, 19:05 (72 days ago) @ David Turell

700,000 years earlier than previously thought:

https://www.newscientist.com/article/2416647-hominins-may-have-left-africa-700000-years...

"Our ancient ancestors may have ventured outside of Africa much earlier than previously believed, according to archaeologists working in Jordan. They say they have found stone tools there that were made and used 2.5 million years ago.

“'Now we know that hominins left Africa at least 700,000 years before we thought,” says Walter Neves at the University of São Paulo in Brazil.

***

"To firm up their case, they have re-examined the purported stone tools and described them in detail. The tools, they say, are a type called Oldowan that have been found at multiple locations in Africa, dating back as far as 3 million years ago.

***

"...he is persuaded that Neves and his colleagues really have made an important discovery. “My take on this is that there is very likely a hominin in Jordan making artefacts prior to 2 million years ago,” says Braun. “I am uncertain exactly how much earlier than 2 million years ago.”

"Because some of the tools were found just above the basalt layer, Neves argues they are probably 2.5 million years old. This makes them older than any known fossils of H. erectus, implying that another hominin species was the first to leave Africa.

"Neves points to Homo habilis, which may have been present 2.3 million years ago or even earlier. “Our hypothesis is that the first hominin to have left Africa was Homo habilis and not Homo erectus,” he says.

"Other researchers have claimed to have evidence of hominins outside Africa older than the Dmanisi remains. At Shangchen in China, researchers have described 2.1-million-year-old stone tools, while at Longgupo, also in China, there are stone artefacts and hominin remains that have been claimed to be 2.5 million years old. There are also claims of stone tools in northern India 2.6 million years ago. However, none of these claims have been widely accepted. Either the artefacts themselves, or their ages, or both, have been questioned.

“'The truth is that we know very little about the earliest excursions of hominins [outside Africa],” says Braun."

Comment: Erectus loved to migrate, gradually moving east and finally north. I think habilis is just an early erectus.

origin of humans; migration to Europe

by David Turell @, Monday, March 18, 2024, 14:48 (34 days ago) @ David Turell

Related to climate 900 thousand years ago:

https://www.sciencealert.com/study-reveals-how-ancient-humans-escaped-climate-extinctio...

"Some 900,000 years ago, humans nearly went extinct.

"According to the results of a genomics study published last year, modern humanity's ancestors were reduced to a breeding population of barely 1,300 individuals in a devastating bottleneck that brought us to the very brink of annihilation. Now, a new study has found that a mass migration of humans out of Africa occurred at the same time.

"It's a discovery that confirms the previous dating of the population decline, and suggests that the two are linked to a common denominator; an event known as the Mid-Pleistocene Transition, in which Earth's climate underwent a period of utter turmoil, wiping out many species.

"The movement of early humans into and across Europe and Asia from Africa is difficult to reconstruct. The best evidence we have consists of a sparse record of bones and mostly stone artifacts, which can be challenging to date. However, the evidence suggests that it wasn't one event, but multiple waves of early hominids and human ancestors that packed up their lives and made long journeys into new environments.

"Two recent studies have linked human migration to a population bottleneck, based on different types of analysis. A close reading of the human genome found that a population bottleneck caused a loss of genetic diversity some 900,000 years ago. A second study, published a few weeks later, studied early archaeological sites in Eurasia, and dated the bottleneck to 1.1 million years ago.

***

"First, the researchers re-evaluated records of sites of early hominid habitation across Eurasia, and found a cluster of sites reliably dated to 900,000 years ago. In comparison, the dating on older sites used as evidence of a population bottleneck was more ambiguous and therefore disputable.

"They compared their findings to marine sediment records, which preserve evidence of changes in the climate in the form of oxygen isotopes. Ratios of oxygen trapped in sediment layers indicate whether the climate was warmer or cooler at the time the minerals were deposited.

"The genomic data and the dating of the hominid sites together suggest that the bottleneck and the migration were simultaneous. During the Mid-Pleistocene Transition, global ocean levels dropped, and Africa and Asia dried out, with large patches of aridity. Hominids living in Africa would have faced horrible conditions depriving them of food and water. Fortunately, with the falling sea level, land routes into Eurasia became available and they were able to skedaddle, according to the researchers' model.

"This is not to say, they carefully note, that hominids had not migrated previously. Rather that the population bottleneck in the ancestor of modern Homo sapiens and the migration thereof occurred at the same time as a result of the climate upheaval that was occurring some 900,000 years ago.

"'We suggest that the enhanced aridity during marine isotope stage 22 that caused the spread of savanna and arid zones across much of continental Africa pushed early Homo populations in Africa to adapt or migrate to avoid extinction," they write in their paper.

"'Rapid migration in response to a severe climate trigger and concomitant means to escape is what can account for the … migration out-of-Africa at 0.9 million years ago and contribute to the modern genomic evidence in modern African populations of the bottleneck.'"

Comment: no question that marked climate changes will drive migrations. The 'population bottleneck' has been presented here previously.

origin of humans; migration to Persian plateau

by David Turell @, Monday, March 25, 2024, 19:07 (27 days ago) @ David Turell

Trying to follow the paths:

https://www.sciencedaily.com/releases/2024/03/240325114147.htm

"A new study combining genetic, palaeoecological, and archaeological evidence has unveiled the Persian Plateau as a pivotal geographic location serving as a hub for Homo sapiens during the early stages of their migration out of Africa.

"This revelation sheds new light on the complex journey of human populations, challenging previous understandings of our species' expansion into Eurasia.

"The study, published in Nature Communications, highlights a crucial period between approximately 70,000 to 45,000 years ago when human populations did not uniformly spread across Eurasia, leaving a gap in our understanding of their whereabouts during this time frame.

"Key findings from the research include:

"The Persian plateau as a hub for early human settlement: Using a novel genetic approach combined with palaeoecological modelling, the study revealed the Persian Plateau as the region where from population waves that settled all of Eurasia originated.

"This region emerged as a suitable habitat capable of supporting a larger population compared with other areas in West Asia.

"Genetic resemblance in ancient and modern populations: The genetic component identified in populations from the Persian Plateau underlines its long-lasting differentiation in the area, compatible with the hub nature of the region, and is ancestral to the genetic components already known to have inhabited the Plateau.

"Such a genetic signature was detected thanks to a new approach that disentangles 40,000 years of admixture and other confounding events. This genetic connection underscores the Plateau's significance.

***

"'The Persian Plateau emerges as a key region, underlining the need for further archaeological explorations."

"First author Leonardo Vallini of the University of Padova, Italy, said: "The discovery elucidates a 20,000 year long portion of the history of Homo sapiens outside of Africa, a timeframe during which we interacted with Neanderthal populations, and sheds light on the relationships between various Eurasian populations, providing crucial clues for understanding the demographic history of our species across Europe, East Asia, and Oceania."

"'The Persian Plateau emerges as a key region, underlining the need for further archaeological explorations.'"

Comment: the area of Israel has shown many ancient sites for sapiens activity on their way to the Persian plateau.

origin of humans; the loss of Neanderthals

by David Turell @, Wednesday, March 27, 2024, 12:39 (25 days ago) @ David Turell

They lost, we won, but why?:

https://www.sciencealert.com/modern-humans-thrived-while-neanderthals-disappeared-but-n...

"Why did humans take over the world while our closest relatives, the Neanderthals, became extinct? It's possible we were just smarter, but there's surprisingly little evidence that's true.

"Neanderthals had big brains, language and sophisticated tools. They made art and jewellery. They were smart, suggesting a curious possibility. Maybe the crucial differences weren't at the individual level, but in our societies.

"Two hundred and fifty thousand years ago, Europe and western Asia were Neanderthal lands. Homo sapiens inhabited southern Africa. Estimates vary but perhaps 100,000 years ago, modern humans migrated out of Africa.

"Forty thousand years ago Neanderthals disappeared from Asia and Europe, replaced by humans. Their slow, inevitable replacement suggests humans had some advantage, but not what it was.

***

"Neanderthals mastered fire before we did. They were deadly hunters, taking big game like mammoths and woolly rhinos, and small animals like rabbits and birds.

"They gathered plants, seeds and shellfish. Hunting and foraging all those species demanded deep understanding of nature.

"Neanderthals also had a sense of beauty, making beads and cave paintings. They were spiritual people, burying their dead with flowers.

"Stone circles found inside caves may be Neanderthal shrines. Like modern hunter-gatherers, Neanderthal lives were probably steeped in superstition and magic; their skies full of gods, the caves inhabited by ancestor-spirits.

"Then there's the fact Homo sapiens and Neanderthals had children together. We weren't that different. But we met Neanderthals many times, over many millennia, always with the same result. They disappeared. We remained.

***

"Modern hunter-gatherers provide our best guess at how early humans and Neanderthals lived. People like the Namibia's Khoisan and Tanzania's Hadzabe gather families into wandering bands of ten to 60 people. The bands combine into a loosely organised tribe of a thousand people or more.

"These tribes lack hierachical structures, but they're linked by shared language and religion, marriages, kinships and friendships. Neanderthal societies may have been similar but with one crucial difference: smaller social groups.

"What points to this is evidence that Neanderthals had lower genetic diversity.

"In small populations, genes are easily lost. If one person in ten carries a gene for curly hair, then in a ten-person band, one death could remove the gene from the population. In a band of fifty, five people would carry the gene – multiple backup copies. So over time, small groups tend to lose genetic variation, ending up with fewer genes.

"In 2022, DNA was recovered from bones and teeth of 11 Neanderthals found in a cave in the Altai Mountains of Siberia. Several individuals were related, including a father and a daughter – they were from a single band. And they showed low genetic diversity. (my bold)

***

"But the Altai Neanderthals often had one version of each gene. As the study reports, that low diversity suggests they lived in small bands – probably averaging just 20 people.

"It's possible Neanderthal anatomy favoured small groups. Being robust and muscular, Neanderthals were heavier than us. So each Neanderthal needed more food, meaning the land could support fewer Neanderthals than Homo sapiens.

"And Neanderthals may have mainly eaten meat. Meat-eaters would get fewer calories from the land than people who ate meat and plants, again leading to smaller populations.

"If humans lived in bigger groups than Neanderthals it could have given us advantages.

***

"Big societies have other, subtler advantages. Larger bands have more brains. More brains to solve problems, remember lore about animals and plants, and techniques for crafting tools and sewing clothing. Just as big groups have higher genetic diversity, they'll have higher diversity of ideas.

"And more people means more connections. Network connections increase exponentially with network size, following Metcalfe's Law. A 20-person band has 190 possible connections between members, while 60 people have 1770 possible connections.

"Information flows through these connections: news about people and movements of animals; toolmaking techniques; and words, songs and myths. Plus the group's behaviour becomes increasingly complex.

***

"To paraphrase poet John Dunne, no man – and no Neanderthal – is an island. We're all part of something larger. And throughout history, humans formed larger and larger social groups: bands, tribes, cities, nation states, international alliances.

"It may be then that an ability to build large social structures gave Homo sapiens the edge, against nature, and other hominin species."

Comment: this approach of larger civil and societal groups as a human advantage makes more sense than any other discussion I've seen.

origin of humans; a new massive analysis

by David Turell @, Saturday, March 30, 2024, 17:46 (22 days ago) @ David Turell

A study of almost every available worldwide fossil:

https://evolutionnews.org/2024/03/fossil-friday-new-dating-of-pleistocene-fossils-rewri...

"They re-dated the earliest occurrences of Homo sapiens in Africa, the Levant and Europe, and confirm that “if Apidima 1 is indeed a H. sapiens, it documents the earliest known presence of our species in Eurasia with an estimated age of about 211 thousand years, while the Misliya cave material from Israel “still represents the earliest known derived H. sapiens in the Levant” with an age of 152 thousand years”. Both dates are much earlier than the traditional Out-of-Africa scenario would predict to find.

***

"...they provided an updated summary of our present understanding of human evolution, with remarkable admissions such as the “co-existence of multiple lineages (in our view, species) over the last 2 million years, with at least 4 of these persisting into the last 100,000 years”, or that studies “show that searching for deep single points of origin for lineages like H. sapiens may ultimately be a futile task.”

"However, the most important take-home message is shown in figure 85...It shows that several different alleged species of the genus Homo lived contemporary in the Pleistocene and experienced various instances of gene flow. This strongly suggests to me and some other critics of the current consensus that all these assumed species are just different populations of a single species Homo sapiens, that at best would qualify as subspecies or geographical races. I will provide a detailed argument for such reclassification in a book-length treatment of archaic Homo that is currently in preparation.

"The most recent data on human fossils and their dating do not really support an evolutionary narrative from ape-like ancestors to modern humans, but a gap between ape-like australopithecines and real humans, as well as just a very diverse human species that even featured a greater morphological and genetic diversity in the past than today. Darwin critics with a Biblical perspective may find it interesting that this would resonate quite well with population genetic models based on a first pair with designed heterozygotic diversity and a significant population bottle neck (Sanford et al. 2018, Hössjer & Gauger 2019)." (my bold)

Comment: this is Bechly from a very ID viewpoint. The references just above are ID science articles. I've reviewed the enormous study he has used for his commentary. Generally, they used advanced dating techniques to show most fossils wee older than originally dated. Note my bold. Either they are not available, or the fossil gap between Australopithecus and real humans exists as true history. Such a gap literally demands a designer, just as the Cambrian gap does.

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