origin of humans (Origins)
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 (152 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 (58 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 (48 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 (42 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 (14 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.