Paleolithic Papers #32

Genus Homo:

H. sapiens (modern humans):

Stone tools have been recovered from Cooper's Ferry, Idaho (USA) dating from 16,000 years ago.

Was the basal most H. sapiens surprisingly modern 500,000 years ago?

Human hearts evolved for endurance.

Foot prints have been found on Calvert Island, British Columbia dating from over 10,000 years ago.

H. neanderthalensis (Neandertals):

There was a shift at a single site of how stone tools were made during Late Acheulian the at Caune de l’Arago.

Did modern humans and Neandertals keep interbreeding over a long period?

Did the Neandertal Eustachian tube contribute to their extinction?

Neandertals were more innovative with their tools than normally credited.

The Neandertals footprints give insight into their social lives.

How Neandertals used birds, including their feathers, in the Qesem Cave, Israel.

Denisovans:

Denisovans seem to have had fingers more like modern humans than Neandertals.

Using genetics and epigenetics, researchers have reconstructed the shape of the face of at least one Denisovan.  The facial features are distinct from Neandertals and modern humans.

The introgression of Denisovan genetics into modern humans gave us an immunity boost.

Sima de los Huesos Hominin

At least one of the Simea de los Huesos proto Neandertals seems to have been murdered.

One of the hominins at Sima de los Huesos had a pathological growth for its ears.  It might not have made the individual deaf after all.

The cochlea evolution of the Simea de los Huesos Hominins gets examined.

H. naledi:

H. naledi's baby teeth were unique.

Genus Paranthropus:

P. robustus:

The femural neck of P. robustus gets examined.

Genus Australopithecus:

What were the Australopithecines?

Australopithecines seem to have breast fed longer than their contemporaries.

A. anamensis:

A nearly complete skull of A. anamensis gives a face to the species and shows evolution is messy showing even in hominins species often overlap in time.

META:

The trabecular boot gets examined in 4 different hominins.

Humans are unique in how they digest fatty foods.

Did a single gene mutation 3.3 million years ago make hominins prone to heart attacks?

Paleolithic Papers #28

Genus Homo:

How did ancient Homo choose places to do its cave paintings?

H. sapiens (modern humans):

Apparently, Late Pleistocene hunter gatherers survived in Iberian ancestry.

Modern humans originated in South Africa and spread through Africa just before migrating out of the continent.

Researchers have found a narrative piece of art from Paleolithic Europe.

A very bold paper claims Australian Aboriginals arrived in Australia 120,000 years ago.

Neandertals:

A commentary is made on the dating of La Quina Amont.

Neandertals might have had adaptations to the cold like wooly mammoths.

Denisovans:

The first pieces of Denisovan skulls have been verified.

Tongzi Hominin:

The Tongzi hominin's teeth are not like H. erectus teeth like had been previously thought.

H. floresiensis (Hobbits):

The environment of Flores at the time of the Hobbit was explored: it was a grassland!  Or so sayeth the rats.

H. erectus:

How big were the groups in Paleolithic India?

H. erectus purposefully started fires on grasslands.  Time to rethink the anthropocene start, folks.

H. naledi:

The root and pulp morphology of a molar for H. naledi gets examined.

Genus Australopithecus:

The brain sizes of A. afarensis and A. africanus are examined.  Did they grow large from eating bone marrow?

Genus Paranthropus:

Dental caries were found in a molar from a P. robustus.

Comparing the metatarsal of Paranthropus to extent hominoids.

META:

The ability to miniaturize stone tools sets hominins apart from other primates.

Did the slowing of the Antarctic current regulate the glaciation cycle?

Green corridors in the Sahara might have facilitated hominin dispersal.

The grandmother hypothesis might explain why women live longer than men.

Why do humans have wisdom teeth that need to be removed?

Unravelling ancient signals of DNA introgression in modern humans.

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 #20

Genus Homo:

Were movable eye brows a significant force in human evolution?

Hominins were not present where megafauna were common, but may have still contributed to the mass extinction.

Where did the Neandertal introgression hypothesis originate?

Just what butchered a rhino in the Philippines 709,000 years ago?

A cave in Kenya gives insight into technological innovation over millennia during the Pleistocene.

The onset of the Achuelean in East Africa is examined.

H. sapiens:

A modern human finger bone has been found in Saudi Arabia dating from over 85,000 years ago.

John Hawks looks back at the idea the Clovis Culture was the first one in the Americas.

The origin of fluted point technology in the ice free corridor in North America.

Long distance pigment trade and use in Mesolithic Africa.

The environmental conditions at the onset of the Mesolithic in Africa.

Variation in the temporal labyrinth as evidence of out of Africa.

Stone artifacts where recovered from Sulawesi, Indonesia dating from 65,000 years ago, suggesting modern humans arrived much earlier than previously thought.

Genomic research linked North African, subsaharan and Middle Eastern populations during the Late Pleistocene.

A recent paper argues a 5 meter long wooden sculpture from Siberia is from the twilight of the Pleistocene and the oldest known monumental art.

Symbolic emblems from the Middle East hint that the Levantine Aurignacian had a distinct, regional culture.

Modern Humans started making certain types of stone tools over ten thousand years earlier than previously thought.

The ability to focus on details led to a revolution in cave paintings.

Evidence of waves of immigrants into the Southeast Asia come from genetics.

How humans survived the Toba event.

H. neanderthalensis:

Neandertals actually had a rather unique nasal system and breathed primarily through their nose, even when breathing heavily.  Could that have been a cold weather adaptation?  After all, our noses help warm and moisten the air as it comes in.

Scientists are hoping to grow brain organoids using Neandertal DNA and observe differences between Neandertals and modern humans.

Neandertals might have have had Mediterranean maritime odysseys since their tools were found on the island of Crete.

How much insight do artifacts from Crimea give into Neandertal symbolism?

Differences between Neandertal and modern human mandibular ramus are considered.

The 'endocostal ossifications' of the K 2 Neandertal get reconsidered.

H. floresiensis:

The experiences of one of the discoverers of the Hobbit and John Hawks' amplification of that.

H. erectus:

KNM-WT 1500's weight has had important implications for understanding H. erectus growth.

KNM-ER 42700:

KNM-ER 42700 is NOT Homo erectus, but rather a different, unknown hominin species.

H. naledi:

Enamel growth on H. naledi's teeth gets considered.

The complexity of H. naledi's brain is examined.

Genus Australopithecus:

Modern human gait predates the genus Homo.

Human hip joint loading was present in A. africanus and P. robustus.

META:

Our understanding of hominin evolution is shaped by sampling bias.

Developed Olduwan A should be abandoned as a term since there is no difference between it and Olduwan.

A new hominin has been found circa 2 million years ago from Ethiopia. 

What we inherited from our insectivorous ancestors.

Paleolithic Papers #17

Genus Homo:

The brains of modern humans are different than other primates in particular ways.

Modern Humans (H. sapiens):

Ancient DNA from South Africa pushes back the origins of modern humans.

How did ancient humans organize themselves?  Check their genomes.

Did the first Americans come via the Kelp Highway?  More evidence.

Ancient mitochondrial DNA studies have shown three different groups swept into Labrador and Newfoundland at different times.

Hobbits (H. floresiensis):

How the Hobbit, LB1, was found.

Did Hobbits eat rats?

Denisovans:

John Hawks disagrees when the Denisovans and Neandertals split.

Neandertals (H. neanderthalensis):

New wrist bones from the Neandertals of El Sidron, Spain have been found and studied.

The Mousterian Neandertals of China are discussed.

A high coverage DNA Neandertal genome has been recovered from Vindijia, Croatia.

The interbreeding between modern humans and Neandertals reintroduced older, lost DNA from ancient, older hominins to the modern human genome.

The interaction between Neandertals and modern humans has been modeled.

A paper suggested modern humans replaced Neandertals through immigration.  A response has been posted.

H. heidelbergensis:

Did the sinuses of H. heidelbergensis have a special role or placement? 

H. naledi:

Reviewing the September excavations at the Rising Star Caves.

An H. naledi pelvis is examined and found to have characteristics of Homo and Australopithecus pelvises.

Genus Paranthropus:

P. robustus:

Isotopic analysis of P robustus teeth show the environments and even movements of individuals lived in.

META:

Crocodiles may make similar marks on bones when feeding like those interpreted to be done by stone tools and flakes used for butchery by hominins.

The jaws of hominins and their variation give important clues as to whether or not they belong to a specific species.

There are deep concerns some of the fossils from Europe of hominins were stolen and used in a study.  Even the journal has grown concerned.

Stone tools from late Oldowon from the Olduvai are investigated with new digs.

Pounding tools from the Oldowon to Acheulen transition are examined as well.

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 #11

Genus Homo:

Genital Warts are from interactions, ahem, between modern humans and Neandertals.

H. sapiens:

There is evidence of learning in the Magdalenian culture.

Modern humans may have hunted cave lions for their pelts.

Modern humans also recognize snakes far better than other animals when they are partially obscured.

Mesolithic cultures in Ethiopia may have used several methods to create ochre.

How Mesolithic cultures used small mammals.

How early Homo might have used tubers for food.

Evidence of early modern human tools from East Timor from 42,000 years ago?

H. neanderthalensis:

Neandertal genes may have helped modern humans adapt to life outside of Africa.

However, many Neandertal genes have been very actively selected against.

H. erectus:

Researchers looked at the cranial vaults of non human primates to try to explain the hypertrophied skull in H. erectus.

H. naledi:

Based on skull shape, H. naledi may be closely related to Homo erectus.

The upper limb, skull and thigh/leg of H. naledi get described.

Genus Paranthropus:

Paranthropus species may have eaten a softer diet than previously thought.

 

META:

Comparing the isotopes found in modern ape and monkey population teeth gives insight into past homin diets.

John Hawks discusses the monkey creation of stone flakes.

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.

Many Early Hominins Generally Smaller-bodied Than Previously Thought

Body mass estimates of hominin fossils and the evolution of human body size

Authors:

Grabowski et al

Abstract:

Body size directly influences an animal's place in the natural world, including its energy requirements, home range size, relative brain size, locomotion, diet, life history, and behavior. Thus, an understanding of the biology of extinct organisms, including species in our own lineage, requires accurate estimates of body size. Since the last major review of hominin body size based on postcranial morphology over 20 years ago, new fossils have been discovered, species attributions have been clarified, and methods improved.

Here, we present the most comprehensive and thoroughly vetted set of individual fossil hominin body mass predictions to date, and estimation equations based on a large (n = 220) sample of modern humans of known body masses. We also present species averages based exclusively on fossils with reliable taxonomic attributions, estimates of species averages by sex, and a metric for levels of sexual dimorphism. Finally, we identify individual traits that appear to be the most reliable for mass estimation for each fossil species, for use when only one measurement is available for a fossil.

Our results show that many early hominins were generally smaller-bodied than previously thought, an outcome likely due to larger estimates in previous studies resulting from the use of large-bodied modern human reference samples. Current evidence indicates that modern human-like large size first appeared by at least 3–3.5 Ma in some Australopithecus afarensis individuals. Our results challenge an evolutionary model arguing that body size increased from Australopithecus to early Homo. Instead, we show that there is no reliable evidence that the body size of non-erectus early Homo differed from that of australopiths, and confirm that Homo erectus evolved larger average body size than earlier hominins.

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.