Paleolithic Papers #25

Genus Homo:

Stone tools found in China from the Pleistocene of the Levallois tradition hint at a potential local development of the technology.

A cave painting in Borneo in Indonesia dates from 40,000 years ago.

Inbreeding was common in hominins.

Crossing out of Africa was not difficult because the Arabian peninsula was green.

Hominins were not the cause the megafaunal extinctions in Africa, rather climate and the expansion of the grasslands were.  Unless, of course, the evidence for H. erectus purposefully expanding the grasslands with fire are accurate.

How did human language arise?  We don't really know.

How did members of the genus Homo survive in east Africa from paleolithic to mesolithic?

Analyzing Aurignacian tools using morphometrics.

A Russian site and its dating from the Upper Paleolithic is discussed and explored more.

H. sapiens:

The Lago Santa people had African-like features and were possibly Clovis culture descendants.  The peopling of South and Central America turned out to be fairly complicated.

The peopling of the Americas is getting a lot of interest once more with genetic studies.

Multiple types of projectiles found in Texas hint at potentially multiple migrations into the Americas.  Note: this could also be an example of a transition from one projectile point technology to another.

It seems the dispersals into the AMericas were more complex and hint at an Australasian component.

How did people cross the Wallace Line?

How the environment of northwestern Argentina changed across the Pleistocene/Holocene boundary.

People appear to have inhabited Tibet at least as early as 30,000 years ago.  This is much earlier than previously thought.

Star watching to understand the seasons may have very early origins.  Cave paintings from 40,000 years ago definitely suggest this.

Why do modern humans have round heads?

H. neanderthalensis:

Neandertals were just as violent as modern humans.

Neandertal children suffered from extreme stress during the winter.  Lead exposure was noted.

Neanderthals in the Caucasus transported obsidian over 250 km to make tools with.

Neandertal genes associated with neurogenesis in modern humans have been found.

H. erectus:

Are stone tools of the Acheulean style from 190k to 240k years ago a sign Homo erectus survived in Saudi Arabia until a late date?

H. erectus social behavior is discussed wrt an animal carcass. 

H. habilis:

Oldowon stone tools, the style associated with Homo habilis, have been found in Algeria dating from 2.4 million years ago.

Genus Australopithecus:

Little Foot, a likely A. africanus, is emerging from the stone matrix it was preserved in.

Little Foot's brain endocast suggests a more basal, chimpanzee like brain.

The original studies of A. africanus when it was known as A. prometheus are discussed.

Genus Paranthropus:

The scapular anatomy of P. bosei gets studied.

KNM-ER 47000 appears to be from P. bosei.

META:

U-Pb dating of flowstones from South Africa constrains the dates hominins were evolving there and shows they were living in dry climate conditions.

Trabecular Bone Fraction gets compared between modern humans, hominins and other primates.

The stone tool gripping abilities of modern humans, hominins and apes are compared.

3d analysis of bone tools sheds some light on how they were made and used.

Three plus different hominins coexisted in the early Pleistocene ~2 million years ago in the Omo-Turkana Basin (P. bosei, H.habilis and H. erectus. possibly H. rudolfensis as well).

What was the dietary diversity of early Pleistocene hominins?

The trabecular structure of the distal femur is compared between humans, apes and baboons is compared.

Paleolithic Papers #16

Genus Homo:

H. sapiens (modern humanity):

Humans are still evolving.

Did modern humans leave Africa to attempt to escape a drying climate?

Facial phenotypes support a multiple dispersal for modern humans.

Modern human spit contains some surprises about our hominin ancestry.

It appears settling down and abandoning, or at least reducing the nomadic life style, allowed technology to start developing faster 64,000 years ago.

Some of the mutations associated with white skin have an African origin.

Did Paleolithic humans realize the dangers of inbreeding and have breeding networks?

A child from 2,000 years ago in south africa gives hints that modern humans originated 300k years ago.

Rock art in Australia appears to show the extinct giant bird Genyornis.

H. neanderthalensis (Neandertals):

DNA analysis of different Neandertal populations advances our understanding of hominin evolution.  (psst, the Altai Neandertals were the hillbillies of their world).

DNA analysis also suggests a higher percentage of Neandertal DNA survives in modern populations.

Neandertals appeared to grow at a similar rate as modern humans.

How thick was the enamel of the Neandertal canine teeth?

Were Neandertals distilling and using tar?

Neandertal City aka Gibraltar, gets profiled.

Rethinking the Upper Paleolithic Transition in Grotte Mandrin.

What was the mechanism that caused the Neandertals to go extinct and be replaced by modern humans?

What traits are tied to the introgression of Neandertal genes into the modern Human line?

H. georgicus:

The Georgian hominins from Dzudzuana and Satsurblia caves are described.

H. erectus:

A trackway from H. erectus in Kenya is studied.

Genus Paranthropus:

P. bosei:

The probable source of herpes has been claimed: Paranthropus bosei.  Yes, friends, one human ancestor couldn't keep it zipped.  I'm looking at you, H. erectus.  Like we REALLY believe the watering hole story, Upright Man.

Genus Australopithecus:

A. anamensis:

Where did A. anamensis live?  What sort of environment was it?

META:

The fossils trackways from the Greek hominin from 5.7 million years ago are in danger.

How facial features have evolved in hominins through time.

Chimps can learn to use tools without being taught.

Savannah living chimps don't seem to eat more meat than their forest cousins.

The rest of their dietary comparison is here.

Tool using macaques are wiping out shellfish populations.

Was bipedality in hominins a by-product of developmental processes?

The differences in loading on the 3rd metacarpal heads in humans and chimpanzees.

Paleolithic Papers #2

Modern Humanity (Homo sapiens):

An infant was found buried with shells that are interpreted as ornamental from 74,000 years ago in Africa.

Melanesians have both Neandertal and Denisovan genes. Paper link.

It seems modern Humans and Neandertals interbred at least 5 times in the last 60,000 years.

Neandertals (Homo neanderthalensis):

Isotopic evidence shows Neandertals were omnivores.

The Sima de los Huesos hominins have been called early Neandertals now. This may spark a academic bun fight because they were declared distinct from Neandertal and Denisovan this past year.   Nature has a pop sci write up on it, too.

Homo antecessor:

The oldest known animal butchery in Europe has been discovered in Thuringa, Germany dating from 1.07 Million Years ago. This predates the Neandertals.

Pliocene/Pleistocene Olduvai Gorge Hominin Habitat:

The habitat of Paranthropus bosei and Homo habilis has been reconstructed and it was far from a paradise.

Homo habilis & Paranthropus boisei Pleistocene Quaternary Habitat was NOT the Garden of Eden

Scientists have pieced together an early human habitat for the first time, and life was no picnic 1.8 million years ago.

Our human ancestors, who looked like a cross between apes and modern humans, had access to food, water and shady shelter at a site in Olduvai Gorge, Tanzania. They even had lots of stone tools with sharp edges, said Gail M. Ashley, a professor in the Rutgers Department of Earth and Planetary Sciences in the School of Arts and Sciences.

But "it was tough living," she said. "It was a very stressful life because they were in continual competition with carnivores for their food."

During years of work, Ashley and other researchers carefully reconstructed an early human landscape on a fine scale, using plant and other evidence collected at the sprawling site. Their pioneering work was published recently in the Proceedings of the National Academy of Sciences.

The landscape reconstruction will help paleoanthropologists develop ideas and models on what early humans were like, how they lived, how they got their food (especially protein), what they ate and drank and their behavior, Ashley said.

link.

Feeding Biomechanics and Dietary Ecology of Paranthropus boisei

The Feeding Biomechanics and Dietary Ecology of Paranthropus boisei

Authors:

Smith et al

Abstract:

The African Plio-Pleistocene hominins known as australopiths evolved derived craniodental features frequently interpreted as adaptations for feeding on either hard, or compliant/tough foods. Among australopiths, Paranthropus boisei is the most robust form, exhibiting traits traditionally hypothesized to produce high bite forces efficiently and strengthen the face against feeding stresses. However, recent mechanical analyses imply that P. boisei may not have been an efficient producer of bite force and that robust morphology in primates is not necessarily strong. Here we use an engineering method, finite element analysis, to show that the facial skeleton of P. boisei is structurally strong, exhibits a strain pattern different from that in chimpanzees (Pan troglodytes) and Australopithecus africanus, and efficiently produces high bite force. It has been suggested that P. boisei consumed a diet of compliant/tough foods like grass blades and sedge pith. However, the blunt occlusal topography of this and other species suggests that australopiths are adapted to consume hard foods, perhaps including grass and sedge seeds. A consideration of evolutionary trends in morphology relating to feeding mechanics suggests that food processing behaviors in gracile australopiths evidently were disrupted by environmental change, perhaps contributing to the eventual evolution of Homo and Paranthropus.

Did Paranthropus bosei Subsist on Tiger Nuts?

An Oxford University study has concluded that our ancient ancestors who lived in East Africa between 2.4 million-1.4 million years ago survived mainly on a diet of tiger nuts. Tiger nuts are edible grass bulbs still eaten in parts of the world today. The study published in the journal, PLOS ONE, also suggests that these early hominins may have sought additional nourishment from fruits and invertebrates, like worms and grasshoppers.

Study author Dr Gabriele Macho examined the diet of Paranthropus boisei, nicknamed "Nutcracker Man" because of his big flat molar teeth and powerful jaws, through studying modern-day baboons in Kenya. Her findings help to explain a puzzle that has vexed archaeologists for 50 years.

Scholars have debated why this early human relative had such strong jaws, indicating a diet of hard foods like nuts, yet their teeth seemed to be made for consuming soft foods. Damage to the tooth enamel also indicated they had come into contact with an abrasive substance. Previous research using stable isotope analyses suggests the diet of these homimins was largely comprised of C4 plants like grasses and sedges. However, a debate has raged over whether such high-fibre foods could ever be of sufficiently high quality for a large-brained, medium-sized hominin.

Dr Macho's study finds that baboons today eat large quantities of C4 tiger nuts, and this food would have contained sufficiently high amounts of minerals, vitamins, and the fatty acids that would have been particularly important for the hominin brain. Her finding is grounded in existing data that details the diet of year-old baboons in Amboseli National Park in Kenya – a similar environment to that once inhabited by Paranthropus boisei. Dr Macho's study is based on the assumption that baboons intuitively select food according to their needs. She concludes that the nutritional demands of a hominin would have been quite similar.

Dr Macho modified the findings of the previous study on baboons by Stuart Altmann (1998) on how long it took the year-old baboons to dig up tiger nuts and feed on various C4 sources. She calculated the likely time taken by hominins, suggesting that it would be at least twice that of the yearling baboons once their superior manual dexterity was taken into account. Dr Macho also factored in the likely calorie intake that would be needed by a big-brained human relative.

Tiger nuts, which are rich in starches, are highly abrasive in an unheated state. Dr Macho suggests that hominins' teeth suffered abrasion and wear and tear due to these starches. The study finds that baboons' teeth have similar marks giving clues about their pattern of consumption.

In order to digest the tiger nuts and allow the enzymes in the saliva to break down the starches, the hominins would need to chew the tiger nuts for a long time. All this chewing put considerable strain on the jaws and teeth, which explains why "Nutcracker Man" had such a distinctive cranial anatomy.

The Oxford study calculates a hominin could extract sufficient nutrients from a tiger nut- based diet, i.e. around 10,000 kilojoules or 2,000 calories a day – or 80% of their required daily calorie intake, in two and half to three hours. This fits comfortably within the foraging time of five to six hours per day typical for a large-bodied primate.

Dr Macho, from the School of Archaeology at Oxford University, said: 'I believe that the theory – that "Nutcracker Man" lived on large amounts of tiger nuts– helps settle the debate about what our early human ancestor ate. On the basis of recent isotope results, these hominins appear to have survived on a diet of C4 foods, which suggests grasses and sedges. Yet these are not high quality foods. What this research tells us is that hominins were selective about the part of the grass that they ate, choosing the grass bulbs at the base of the grass blade as the mainstay of their diet.

link.

Paranthropus bosei was a Climber During Calabrian Pleistocene

A human ancestor characterized by "robust" jaw and skull bones was a muscular creature with a gorilla-like upper body and more adaptive to its environment than previously thought, scientists have discovered.

Researchers found a partial skeleton -- including arm, hand, leg and foot fragments -- dated to 1.34 million years old and belonging to Paranthropus boisei at the Olduvai Gorge World Heritage fossil site in Tanzania. The find, published in the latest edition of the scientific journal PLOS ONE, represents one of the most recent occurrences of P. boisei before its extinction in East Africa.

"This is the first time we've found bones that suggest that this creature was more ruggedly built -- combining terrestrial bipedal locomotion and some arboreal behaviors -- than we'd previously thought," said Charles Musiba, Ph.D., associate professor of anthropology at the University of Colorado Denver, part of the international research team. "It seems to have more well-formed forearm muscles that were used for climbing, fine-manipulation and all sorts of behavior."

While P. boisei was known for its massive jaws and cranium -- anthropologist Mary Leakey discovered the first skull in 1959 in northern Tanzania -- the build and skeletal adaptations of the rest of the archaic hominin's body have been unknown until recently.

During excavations at Olduvai in 2010-2011, the team discovered the partial skeleton of a large adult individual who is represented by various teeth and skeletal parts. Other team members are Manuel Dominguez-Rodrigo, Ph.D., professor of anthropology and prehistory at Complutense University, Madrid; Audax Mabulla, Ph.D., associate professor of archaeology, University of Dar es Salaam, Tanzania, Gail Ashley, Ph.D., professor of geological sciences, Rutgers University; David Uribelarrea, Ph.D. a professor of geology at Complutense University of Madrid; Henry Bunn, Ph.D., professor of anthropology, University of Wisconsin-Madison; and Travis Pickering, Ph.D., professor of anthropology, University of Wisconsin-Madison.

P. boisei was a long-lived species of archaic hominin that first evolved in East Africa about 2.3 million years ago. In the absence of evidence of other skeletal remains, it was commonly assumed that the skeleton of P. boisei was like that of more ancient species of the genus Australopithecus, from which P. boisei likely evolved.

"We are starting to understand the physiology of these individuals of this particular species and how it actually adapted to the kind of habitat it lived in," Musiba said. "We knew about the kind of food it ate -- it was omnivorous, leaning more toward plant material -- but now we know more: how it walked around and now we know it was a tree climber."

The size of the arm bones suggests strong forearms and a powerful upper body. "It's a different branch on our ancestry tree," Musiba said. "It came later than the other hominins, so the question now is 'what happened to it?' We're going to do more work on biomechanics and see what else this creature was doing."

He noted that the creature likely stood 3.5 to 4.5 feet tall and possessed a robust frame. "We know that it was very strong," Musiba said. "It's unprecedented to find how strong this individual was. The stronger you are the more adaptive you are."

link.