Showing posts with label homo. Show all posts
Showing posts with label homo. Show all posts

Saturday, September 28, 2019

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?

Saturday, April 06, 2019

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.

Saturday, March 16, 2019

Paleolithic Papers #27

Genus Homo:

Scientists are still stumped by the evolution of human breasts.

Hominins in Levant hunted different prey than did the resident hyenas.

H. sapiens:

Pleistocene hunters in Sri Lanka had a taste for monkey meat that lasted a long, long time.

East African hunter gatherers appear to have had a common ancestry.

There are more missing ancestors in our genome other than Neandertals and Denisovans.

Did modern humans self domesticate?

H. neanderthalensis:

Neandertals primary food source was, in fact, meat, at least, at Les Cottés and Grotte du Renne, in France.

What was the impact of the interglacial climate changes on Neandertal diets at Baume Moula-Guercy, Ardèche, France?

The replacement of Neandertals by modern humans was a little more complicated than what used to be thought: there was some, erm, intermingling.

Footprints of Neandertals from Gibraltar have been found.

Some are going hmmm over the stone artifacts at Châtelperronian.

Did inbreeding help do in the Neandertals?

Neandertals walked just like modern people did.

Sima de los Huesos Hominins:

The Middle Pleistocene hominins from Sima de los Huesos had very Neandertal-ish brains.

Denisovans:

Who were they? John Hawks comments.

H. erectus:

Britain may return the iconic Kabwe skull to Zambia.

Genus Paranthropus:

P. robustus:

What was the genetic origin of the pitted enamel hypoplasia in P. robustus?

Genus Aridopithecus:

A. ramidus postcranial remains from Ethiopia get a description.

A. ramidus had adaptations for waling bipedal.

META:

Is the African Eve hypothesis wrong?

Why did menopause evolve?

One paleoanthropologist's hopes for a human evolution museum in Israel.

Human and nonhuman primate brains are compared for clues to human brain evolution.

What were the origins of human language?

The tale of the multiregional hypothesis and the out of africa hypothesis are told.

Can we determine which hominin teeth came from when found?

The current 'gap' in the middle Pleistocene is very important to human evolution.

Root growth for teeth is compared between humans and apes.

Saturday, February 09, 2019

Paleolithic Papers #26

Genus Homo:

How our ancestors survived and adapted 250k years ago.

In the last million years, the mutation rate in the human line has greatly decreased.

Estimating Late middle Pleistocene population sizes.

Hominins may be ecologically unique.

The introgression and hybridization between modern H. sapiens and archaic hominins gets examined.

Ancient DNA from Africa has been starting to be uncovered.

H.  sapiens:

Dogs appear to have been helping hunt as far back as 11,5000 years ago.

Do few tools found mean few people were present?

The seasonal scheduling of shellfish collection from the Mesolithic and more recent are examined.

The oldest dog burial known to date has been found in the Americas dating from the end of the Pleistocene.

Why modern humans evolved different colored skin.

A femur with some unique traits, but probably from anatomically modern humans from the Niah Caves in Malaysia gets examined.

The raw materials used in stone tools in Israel by early H. sapiens is explored.

H. neanderthalensis:

The foot bones of individuals from Montignac-sur-Vézère, Dordogne, France are examined.

The introgression of Neandertals and other archaic hominids had an impact on gene expression in Eurasian populations.

Neandertal spears could be thrown successfully to kill.

Modern humans replaced Neandertals at Bajondillo Cave in Spain 44kya, surprisingly early.

Neandertals introgressing into modern human populations reintroduced alleles that were lost when the ancestors of modern eurasians left africa.

The book, The Smart Neanderthal, gets reviewed.

Neandertals appear to have, in at least a few instances, mass prey killers and then only taken the best parts, leaving the rest.  John Hawks replies.  He also discusses the mass kill site at Gran Dolina, Spain.

Denisovans:

The Denisova Cave in the Altai Mountains was occupied by Denisovans from 192,000 years to almost 52,000 years ago with a period where Neandertals were present.  Stone tools from a hominin date from 300,000 years ago, but it is not clear who made them.  The site was occupied at least until 20,000 years ago.

New unknown hominins:

There appears there is another hominin that modern people recently interbred with.

An archaic hominin from between 150k to 250k years ago had modern tooth eruption.

H. antecessor:

While similar to modern humans in many ways, H. antecessor's were very different.

H. erectus:

It appears Chinese H. erectus populations might have been diverging from Indonesian populations.

Genus Australopithecus:

The era of Australopithecus in South Africa gets a multidisciplinary examination.

Did australopithecines associate with antelope to avoid predators?

A. sediba:

A. sediba is unique species.

A. africanus:

Recently, authors suggested a specimen was of a new species of Australopithecus and resurrected an old name for A. africanus ("A. prometheus").  John Hawks discusses why this won't work.

The long limb bones of StW 573 are studied and discussed..

The bony labyrinth of StW 573 is detailed and what its implications are.

The forearm bones were asymmetrical on StW 573: could that have been a sign of antemortem trauma?

The dental wear of StW 573 was more like A. anamensis than other australopithecines.  Was this evidence it was from a different species than A. africanus?

StW 573's functional anatomy, biomechanical capabilities and potential niche are discussed in light of the new information gathered.

The site where StW 573 was found and its past investigations are detailed.

A. anamensis:

The environment A. anamensis lived in gets examined.

META:

The central place of Africa in human evolution.

Could early hominins crossed water?

How did humans lose their hair and get sweaty?

The importance of human foot muscles to bipedalism.

A new book on the impact of tectonics on human evolution gets reviewed.

Saturday, August 11, 2018

Paleolithic Papers #22

Genus Homo:

What restricted hominin living locations in middle Pleistocene China?

Could the evolution of human beings be the root cause of some mental disorders?

H. sapiens:

Discovery of spearheads and other points in Gault, TX indicate a new, previously unknown and unique stone tool tradition that predates the Clovis culture.

The models of how the Americas were populated get a run down.

Modern humans may have arisen from pockets of semi isolated populations in Africa.

Did modern humans dominate the world because we specialized at being generalists?

The modern pygmy population of Flores, Indonesia shows evidence of Denisovan and Neandertal introgression, but not of older hominins.  This (amongst other information) indicates insular dwarfism arose twice on Flores with two different hominin species and the Hobbits are not related to the modern Rampasasa people of Flores.

H. neanderthalensis:

The Krapina Neandertals used their anterior teeth for tasks other than eating based on their tooth fractures.

Neandertals apparently had a different ontogeny went it came to walking.

Some caution is being urged at using microbiota of the mouth as evidence of the interbreeding between modern humans and Neandertals.

Neandertals appear to have fire starting tools.

H. erectus:

Stone tools from China date from 2.1 million years ago, pushing back in time the exit from Africa by 400kya.  The question is which hominin this is.  H. erectus seems the most likely, but that would mean H. erectus is older than we thought.  John Hawks appears to support the idea this is H. erectus and states there is at least one other Chinese site that has similar dates.

There is a pelvis found that is close to modern humans',  but apparently is really from H. erectus given the rest of the skeleton.  It may be the modern human pelvis was part of the normal variation of later H. erectus.

Island dwarfism in canids during the Pleistocene in Java could have implications for H. erectus and the potential evolution of the 'hobbits,' H. floresiensis.

Did...laziness (?!?!) doom H. erectus?

H. habilis:

The use, reuse and creation of tools at the Oldowan technological site HWK EE.

H. naledi:

3 specimens from the Rising Star cave give some insight into the variation in H. naledi.

Genus Australopithecus:

The hominin jaw underwent significant change in the earliest australopithecines.

A. afarensis and A. sediba walked bipedally differently.

The Swartkrans Oldowan site provided some interesting differences between other Oldowan stone tool sites.

META:

A 2 million year long perspective of the hydroclimatic environment of human evolution in Southeast Africa.

Eating bone marrow shaped the evolution of the hominin hand.

Trabecular bone patterning in the human hand hints at changes as to how the hand was used by hominins.

Saturday, May 26, 2018

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.

Saturday, October 21, 2017

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.

Thursday, April 07, 2016

Paleolithic Papers #4

Australopithecus afarensis:

More afarenesis fossils have been found, including two infants,in Kenya.

Genus Homo:

The nose plays an important part of the conditioning of the air for the lungs.

Did nearby supernova affect human evolution?

Where did early humans get their brain feeding nutrients?

Homo naledi:

Did H. naledi really purposefully bury its dead in the cave in Africa?

Homo erectus:

The biogeography of the dispersion of erectus out of Africa.

Neandertals (Homo neanderthalensis):

The differences between Neandertals and modern humans are being attributed to the differences in diet.

Hobbits (Homo floresiensis):

Hobbits were older than previously thought.

Some are speculating the new dates would imply modern humans wiped out the Hobbits.

John Hawks talks about what the new paper on the Liang Bua's stratigraphy does and does not answer.  It ought to be noted Hawks is calling the Hobbits Homo floresiensis now.

Modern Humans (Homo sapiens):

There was a long layover in Beringia when the PaleoIndians migrated to the New World from Asia.

Puppies of the Paleolithic sounds like a title to a kids book or an odd band, but is entirely accurate in this case.

There is a map of which populations have Denisovan and Neandertal genes.

Some have questions about the introgression of Denisovans and Neandertals into modern humans.

Modern human Y chromosomes do not have Neandertal genes.

There is a hot topic of whether or not warfare is inherent to modern humans.  Some argue it is.  Others believe it is not.  A study in Japan of Holocene hunter gatherers claims to support that war is not a basal part of humanity.

Sunday, March 13, 2016

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.


Saturday, January 09, 2016

How Faces Changed in the Genus Homo

Cranial base topology and basic trends in the facial evolution of Homo

Authors:

Bastir et al

Abstract:

Facial prognathism and projection are important characteristics in human evolution but their three-dimensional (3D) architectonic relationships to basicranial morphology are not clear. We used geometric morphometrics and measured 51 3D-landmarks in a comparative sample of modern humans (N = 78) and fossil Pleistocene hominins (N = 10) to investigate the spatial features of covariation between basicranial and facial elements. The study reveals complex morphological integration patterns in craniofacial evolution of Middle and Late Pleistocene hominins. A downwards-orientated cranial base correlates with alveolar maxillary prognathism, relatively larger faces, and relatively larger distances between the anterior cranial base and the frontal bone (projection). This upper facial projection correlates with increased overall relative size of the maxillary alveolar process. Vertical facial height is associated with tall nasal cavities and is accommodated by an elevated anterior cranial base, possibly because of relations between the cribriform and the nasal cavity in relation to body size and energetics. Variation in upper- and mid-facial projection can further be produced by basicranial topology in which the midline base and nasal cavity are shifted anteriorly relative to retracted lateral parts of the base and the face. The zygomatics and the middle cranial fossae act together as bilateral vertical systems that are either projected or retracted relative to the midline facial elements, causing either midfacial flatness or midfacial projection correspondingly. We propose that facial flatness and facial projection reflect classical principles of craniofacial growth counterparts, while facial orientation relative to the basicranium as well as facial proportions reflect the complex interplay of head-body integration in the light of encephalization and body size decrease in Middle to Late Pleistocene hominin evolution. Developmental and evolutionary patterns of integration may only partially overlap morphologically, and traditional concepts taken from research on two-dimensional (2D) lateral X-rays and sections have led to oversimplified and overly mechanistic models of basicranial evolution.

Sunday, January 03, 2016

Human Evolved More Efficient Sleep, Require Less Than Other Primates

Insomniacs take heart: Humans get by on significantly less sleep than our closest animal relatives. The secret, according to a new study, is that our sleep is more efficient.

Researchers from Duke University scoured the scientific literature and compiled a database of slumber patterns across hundreds of mammals including 21 species of primates -- from baboons and lemurs to orangutans, chimpanzees and people. They then used statistical techniques to account for each species' position in the primate family tree.

They found that humans are exceptionally short sleepers -- getting by on an average of seven hours of sleep a night, whereas other primate species, such as southern pig-tailed macaques and gray mouse lemurs, need as many as 14 to 17 hours.

What's more, our sleep tends to be more efficient, meaning we spend a smaller proportion of time in light stages of sleep, and more of our sleep time in deeper stages of sleep. A dream state called rapid eye movement sleep, or REM, for example, makes up nearly 25 percent of our overall sleep. But in primates such as mouse lemurs, mongoose lemurs and African green monkeys, REM sleep barely climbs above five percent.

"Humans are unique in having shorter, higher quality sleep," said anthropologist and study co-author David Samson of Duke, who logged nearly 2,000 hours watching orangutans in REM and non-REM sleep as part of his dissertation research prior to coming to Duke.

Saturday, January 02, 2016

Lower Paleolithic Bone Tools From Pleistocene Quaternary Schöningen, Germany

Lower Paleolithic bone tools from the ‘Spear Horizon’ at Schöningen (Germany)

Authors:

van Kolfschoten et al

Abstract:

The Lower Paleolithic locality of Schöningen 13 II-4 is famous for the discovery of wooden spears found amongst the butchered remains of numerous horses and other large herbivores. Although the spears have attracted the most interest, other aspects of the associated artifact assemblage have received less attention. Here we describe an extraordinary assemblage of 88 bone tools from the ‘Spear Horizon.’ This sample includes numerous long bone shaft fragments (mostly of horse), three ribs used as ‘retouchers’ to resharpen flint tools, and a complete horse innominate that was used as an anvil in bipolar knapping. Most of the retouchers were prepared by scraping the diaphysis of fresh and dry long bones. Technological analysis of the associated lithic assemblage demonstrates exhaustive resharpening to maintain functional cutting edges. Whereas the flint tools were brought to the site, curated, and maintained, the retouchers had a shorter use-history and were either discarded after a limited period or broken to extract marrow.

Horse and bison metapodials with flaked and rounded epiphyses are interpreted as hammers used to break marrow bones. Several of the ‘metapodial hammers’ were additionally used as knapping percussors. These constitute the earliest evidence of multi-purpose bone tools in the archeological record. Our results highlight the advanced knowledge in the use of bones as tools during the Lower Paleolithic, with major implications for understanding aspects of non-lithic technology and planning depth in early hominins.

Saturday, December 26, 2015

Homo erectus Didn't Have a Uniquely Thick Skull

Cranial vault thickness in primates: Homo erectus does not have uniquely thick vault bones

Authors:

Copes et al

Abstract:

Extremely thick cranial vaults have been noted as a diagnostic characteristic of Homo erectus since the first fossil of the species was identified, but relatively little work has been done on elucidating its etiology or variation across fossils, living humans, or extant non-human primates. Cranial vault thickness (CVT) is not a monolithic trait, and the responsiveness of its layers to environmental stimuli is unknown.

We obtained measurements of cranial vault thickness in fossil hominins from the literature and supplemented those data with additional measurements taken on African fossil specimens. Total CVT and the thickness of the cortical and diploë layers individually were compared to measures of CVT in extant species measured from more than 500 CT scans of human and non-human primates.

Frontal and parietal CVT in fossil primates was compared to a regression of CVT on cranial capacity calculated for extant species. Even after controlling for cranial capacity, African and Asian H. erectus do not have uniquely high frontal or parietal thickness residuals, either among hominins or extant primates. Extant primates with residual CVT thickness similar to or exceeding H. erectus (depending on the sex and bone analyzed) include Nycticebus coucang, Perodicticus potto, Alouatta caraya, Lophocebus albigena, Galago alleni, Mandrillus sphinx, and Propithecus diadema. However, the especially thick vaults of extant non-human primates that overlap with H. erectus values are composed primarily of cortical bone, while H. erectus and other hominins have diploë-dominated vault bones. Thus, the combination of thick vaults comprised of a thickened diploë layer may be a reliable autapomorphy for members of the genus Homo.

Saturday, December 19, 2015

The Maludong Hominin: an Archaic Population Surviving in Southwest China Until 14,000 Years ago


A Hominin Femur with Archaic Affinities from the Late Pleistocene of Southwest China

Authors:


Curnoe et al

Abstract:

The number of Late Pleistocene hominin species and the timing of their extinction are issues receiving renewed attention following genomic evidence for interbreeding between the ancestors of some living humans and archaic taxa. Yet, major gaps in the fossil record and uncertainties surrounding the age of key fossils have meant that these questions remain poorly understood. Here we describe and compare a highly unusual femur from Late Pleistocene sediments at Maludong (Yunnan), Southwest China, recovered along with cranial remains that exhibit a mixture of anatomically modern human and archaic traits. Our studies show that the Maludong femur has affinities to archaic hominins, especially Lower Pleistocene femora. However, the scarcity of later Middle and Late Pleistocene archaic remains in East Asia makes an assessment of systematically relevant character states difficult, warranting caution in assigning the specimen to a species at this time. The Maludong fossil probably samples an archaic population that survived until around 14,000 years ago in the biogeographically complex region of Southwest China.

Saturday, November 28, 2015

Homo naledi may Date From the Gelasian Pleistocene Quaternary (2 Million Years ago)

Estimating the age and affinities of Homo naledi

Author:

Thackeray

Extract:

Recent discoveries of more than 1500 hominin fossils from the site of Rising Star in the South African Cradle of Humankind, attributed to a new species (Homo naledi), have attracted global interest. As yet no secure date for this extraordinary material has been obtained, and the relationship of this species to other Plio-Pleistocene taxa has been greatly debated in the media. Here I report results of morphometric analyses that may facilitate an assessment of the age and affinities of crania attributed to H. naledi.

pop sci write up.

Tuesday, November 24, 2015

Comparing the Radii From 89 Specimens of the Sierra de Atapuerca Hominins

Fossil hominin radii from the Sima de los Huesos Middle Pleistocene site (Sierra de Atapuerca, Spain)

Authors:

Rodriguez et al

Abstract:

Complete radii in the fossil record preceding recent humans and Neandertals are very scarce. Here we introduce the radial remains recovered from the Sima de los Huesos (SH) site in the Sierra de Atapuerca between 1976 and 2011 and which have been dated in excess of 430 ky (thousands of years) ago. The sample comprises 89 specimens, 49 of which are attributed to adults representing a minimum of seven individuals. All elements are described anatomically and metrically, and compared with other fossil hominins and recent humans in order to examine the phylogenetic polarity of certain radial features. Radial remains from SH have some traits that differentiate them from those of recent humans and make them more similar to Neandertals, including strongly curved shafts, anteroposterior expanded radial heads and both absolutely and relatively long necks. In contrast, the SH sample differs from Neandertals in showing a high overall gracility as well as a high frequency (80%) of an anteriorly oriented radial tuberosity. Thus, like the cranial and dental remains from the SH site, characteristic Neandertal radial morphology is not present fully in the SH radii. We also analyzed the cross-sectional properties of the SH radial sample at two different levels: mid-shaft and at the midpoint of the neck length. When standardized by shaft length, no difference in the mid-shaft cross-sectional properties were found between the SH hominins, Neandertals and recent humans. Nevertheless, due to their long neck length, the SH hominins show a higher lever efficiency than either Neandertals or recent humans. Functionally, the SH radial morphology is consistent with more efficient pronation-supination and flexion-extension movements. The particular trait composition in the SH sample and Neandertals resembles more closely morphology evident in recent human males.

Monday, November 23, 2015

Based on Jaws & Teeth, Homo floresiensis ('Hobbit') Was a Separate Species

An ancient, 3-foot-tall (0.9 meters) human whose diminutive stature has earned it the nickname "hobbit" has puzzled evolutionary scientists since its little bones were discovered on the Indonesian island of Flores. Some have suggested the individual was a Homo sapiens with some miniaturizing disorder.

Now, teeth from the hobbit suggest it belonged to a unique species rather than a modern human with a growth disorder. The new research also suggests hobbits may share a direct ancestor with modern humans.

The 18,000-year-old fossil remains of the hobbit were discovered in 2003. Since then, scientists have suggested that the hobbit, which had a brain about the size of a grapefruit, was a unique branch of the human lineage Homo, dubbed Homo floresiensis. However, other researchers have argued the hobbit was really a modern human with microcephaly, a condition that leads to an abnormally small head, a small body and some mental retardation.

To learn more about the hobbit, scientists have now performed the first comprehensive analysis of the ancient human's teeth. The researchers compared the 40 known hobbit teeth with those from 490 modern humans from Asia, Oceania, Africa and Europe, as well as from a variety of extinct hominins, such as Homo habilis, which is suspected to be among the first makers of stone tools. (Hominins consist of humans and their relatives dating after the split from the chimpanzee lineage.)

The researchers found hobbit teeth were as small as those from short modern humans. However, other features of these teeth looked completely dissimilar from those of modern humans.

The hobbit teeth displayed a unique mosaic of primitive traits seen in early hominins mixed with more-advanced traits seen in later hominins, the researchers said. For instance, the canine and premolar teeth looked primitive, whereas the molar teeth looked advanced, or as if they had emerged later in the evolution of Homo sapiens, the scientists said.

Saturday, November 21, 2015

Mistaken Identity: Homo sapiens did NOT Appear in Indonesia Before 115,000 years ago

Dental size reduction in Indonesian Homo erectus: Implications for the PU-198 premolar and the appearance of Homo sapiens on Java

Authors:

Polanski et al

Abstract:

The recent recovery of a hominin maxillary third premolar, PU-198, within the faunal collections from Punung Cave (East Java) has led to assertions that Homo sapiens appeared on Java between 143,000 and 115,000 years ago. The taxonomic assignment of PU-198 to H. sapiens was based predominantly on the small size of the specimen, following an analysis which found little to no overlap in premolar size between Homo erectus and terminal Pleistocene/Holocene H. sapiens. Here, we re-evaluate the use of size in the taxonomic assignment of PU-198 in light of 1) new buccolingual and mesiodistal measurements taken on the fossil, 2) comparisons to a larger sample of H. erectus and H. sapiens maxillary third premolars, and 3) evidence of a diachronic trend in post-canine dental size reduction among Javan H. erectus. Our results demonstrate PU-198 to be slightly larger than previously suggested, reveal substantial overlap in premolar size between H. erectus and H. sapiens, and indicate a statistically significant reduction in premolar size between early and late Javan H. erectus. Our findings cast doubt on the assignment of PU-198 to H. sapiens, and accordingly, question the appearance of H. sapiens on Java between 143,000 and 115,000 years ago.

Monday, November 16, 2015

Denisovans Sister Group to Neandertals, More Genetically Diverse & Inhabited Siberia for Long Time

Nuclear and mitochondrial DNA sequences from two Denisovan individuals

Authors:

Sawyer et al

Abstract:

Denisovans, a sister group of Neandertals, have been described on the basis of a nuclear genome sequence from a finger phalanx (Denisova 3) found in Denisova Cave in the Altai Mountains. The only other Denisovan specimen described to date is a molar (Denisova 4) found at the same site. This tooth carries a mtDNA sequence similar to that of Denisova 3. Here we present nuclear DNA sequences from Denisova 4 and a morphological description, as well as mitochondrial and nuclear DNA sequence data, from another molar (Denisova 8) found in Denisova Cave in 2010. This new molar is similar to Denisova 4 in being very large and lacking traits typical of Neandertals and modern humans. Nuclear DNA sequences from the two molars form a clade with Denisova 3. The mtDNA of Denisova 8 is more diverged and has accumulated fewer substitutions than the mtDNAs of the other two specimens, suggesting Denisovans were present in the region over an extended period. The nuclear DNA sequence diversity among the three Denisovans is comparable to that among six Neandertals, but lower than that among present-day humans.

pop sci write up at Nat Geo.

Friday, October 30, 2015

New Geoarchaeological Finds in Liang Bawah, the Cave Beneath

Geoarchaeological finds below Liang Bua (Flores, Indonesia): A split-level cave system for Homo floresiensis?

Authors:

Gagan et al

Abstract:

We report on new geoarchaeological finds in a recently discovered cave-chamber (Liang Bawah, “Cave Underneath”) positioned below Liang Bua on the island of Flores, Indonesia, where the type specimen for Homo floresiensis was recovered from Late Pleistocene sediment. At the rear of Liang Bua, a 23-m-long shaft, inclined at 60°, leads to a lower chamber measuring 23 m × 24 m × 5 m high (about half the size of Liang Bua). Stone artefacts and bones were found shallowly buried in rubble at the base of the shaft, and around a 5-m-high mud mound that fills the northwest sector of Liang Bawah. We recovered 17 stone artefacts made from chert and volcanics, and more than 220 well-preserved bone elements belonging to endemic giant rats, pigs, primates, small murid rodents, bats and introduced species. Multi-collector inductively coupled plasma mass spectrometer (MC-ICPMS) analysis of uranium and thorium in carbonate coatings on four bones yielded ages of ~ 240–180 ka (endemic giant rat femur), ~ 110–60 ka (unidentified phalanx), ~ 33–23 ka (pig skull fragment), and ~ 7–3 ka (giant rat femur), which overlap with the ~ 95 to 17 ka occupation of Liang Bua by H. floresiensis. The ~ 33–23 ka age of the pig skull fragment indicates that Sus sp. may have dispersed into island Southeast Asia earlier than previously recognised. The passageway at the rear of Liang Bawah, and a currently buried front entrance, represent two possible transport paths for cultural and faunal material to the cave-chamber. Analysis of the geomorphic evolution of Liang Bawah shows that it may have been a Late Pleistocene depocentre for material transported from the occupation chamber of Liang Bua, and a repository for human subsistence refuse, or pit-fall trap, via the rear passage. These physical attributes, and the antiquity of the faunal remains found thus far, indicate that Liang Bawah could contain an archive of the Late Pleistocene and, potentially, remains of H. floresiensis.