Stone handaxes, similar to those made
by early humans as much as 1.5 million years ago, have been dated for
the first time in the Arabian Peninsula, to less than 190,000 years old,
where their production may have endured until the arrival of Homo
sapiens.
Max Planck Institute for the Science of Human History
IMAGE: These are handaxes from the site of Saffaqah, Saudi Arabia.
view more
Credit: Palaeodeserts (Ian R. Cartwright)
Beginning more than 1.5 million years ago, early humans made stone
handaxes in a style known as the Acheulean - the longest lasting
tool-making tradition in prehistory. New research led by the Max Planck
Institute for the Science of Human History and the Saudi Commission for
Tourism and National Heritage has documented an Acheulean presence in
the Arabian Peninsula dating to less than 190,000 years ago, revealing
that the Arabian Acheulean ended just before or at the same time as the
earliest Homo sapiens dispersals into the region.
Much attention has been given to understanding the spread of our own
species, Homo sapiens, first within Africa and then beyond. However,
less attention has been given to where diverse groups of close
evolutionary cousins lived in Eurasia immediately prior to the arrival
of Homo sapiens. Understanding this is critical because the spatial and
temporal characteristics of such groups reveal the human and cultural
landscape first encountered by our species on leaving Africa.
The youngest Acheulean site in Southwest Asia
In a paper published in Scientific Reports, an
international team of researchers led by the Max Planck Institute for
the Science of Human History and the Saudi Commission for Tourism and
National Heritage reports the first ever dates obtained from an
Acheulean site in Arabia, the site of Saffaqah, situated in Central
Saudi Arabia. Saffaqah is the first stratified Acheulean site to be
reported in the Arabian Peninsula and the dates reveal that early humans
occupied the site until at least 190,000 years ago. These dates are
surprisingly recent for a region known to feature among the oldest
examples of such technology outside Africa. For example, dates from the
Levant document an ancient Acheulean presence from 1.5 million years
ago. Conversely the site of Saffaqah features the youngest Acheulean
tools yet found in southwest Asia.
Over 500 stone tools, including handaxes and other artefacts known
as cleavers, were recovered from the occupation levels. Some of the
stone flakes used to make handaxes were in such fresh condition that
they were recovered still resting on the stone nodules from which they
had been detached. These and other artefacts show that the early humans
responsible for making them were manufacturing stone tools at this site.
"It is not surprising that early humans came here to make stone
tools," says Dr. Eleanor Scerri of the Max Planck Institute for the
Science of Human History, the lead author of the study. "The site is
located on a prominent andesite dyke that rises above the surrounding
plain. The spot was both a source of raw material as well as a prime
location to survey a landscape that, back then, sat between two major
river systems."
This choice location also seems to have continued to be
attractive to early humans at an even later date than those recorded by
the researchers in this study. Layers containing identical stone
handaxes are also found above the dense occupation layers that were
dated, raising the possibility that Saffaqah is among the youngest
Acheulean sites documented anywhere.
Hominins living at the edge
The new dating results both record the late persistence of the
Acheulean in the Peninsula and also show that as yet unidentified
hominin populations were using networks of now extinct rivers to
disperse into the heart of Arabia during a time of increased rainfall in
the region. This suggests that these hominins were able to live on the
margins of habitable zones and take advantage of relatively brief
"greening" episodes in a generally arid area. The dispersal of these
hominins into the heart of Arabia may also help to explain the
surprisingly late persistence of the Acheulean, as it suggests a degree
of isolation.
"These hominins were resourceful and intelligent," adds Dr. Scerri,
"They dispersed across a challenging landscape using technology commonly
seen as reflecting a lack of inventiveness and creativity. Instead of
perceiving the Acheulean this way, we should really be struck by how
flexible, versatile and successful this technology was."
Cutting edge science
To date the sediments from the site of Saffaqah, the researchers
used a combination of dating techniques known as luminescence methods,
including a newly developed infrared-radiofluorescence (IR-RF) dating
protocol for potassium rich feldspars. The method relies on the ability
of such minerals to store energy induced by natural radioactivity and to
release this energy in the form of light. "The application of IR-RF
dating allowed us to obtain age estimates from sediments that were
previously difficult to reliably date," explains Marine Frouin of the
University of Oxford, one of the researchers involved in the dating
program.
These discoveries and methods are already leading to new research.
"One of the biggest questions we have is whether any of our evolutionary
ancestors and close cousins met up with Homo sapiens, and if this could
have happened somewhere in Saudi Arabia. Future field work will be
dedicated to understanding possible cultural and biological exchanges at
this critical time period," says Professor Michael Petraglia of the Max
Planck Institute for the Science of Human History, the director of the
project which led to the discoveries at Saffaqah.
Ancient stone tools and cut-marked animal bones discovered in
Algeria suggest that modern humans' ancestors called northern Africa
home much earlier than archaeologists once thought, a new study reports.
The data indicates a rapid dispersal of stone tools out of East Africa
and into other regions of the continent - or, alternatively, a multiple
origin scenario of early hominin stone tool manufacture and use in both
East and North Africa. East Africa is widely considered to be the
birthplace of stone tool use by our ancient hominin ancestors - the
earliest examples of which date as far back as about 2.6 million years
ago.
Similar examples of stone tool manufacture and use have been
identified in North Africa, dating to nearly 1.8 million years old and
generally considered to be the oldest archaeological materials in all
the region. In this report, however, Mohamed Sahnouni and colleagues
present new archaeological evidence - Oldowan stone artifacts and
fossilized butchered bones, nearly a half-million years older than those
previously known.
Sahnouni et al. uncovered the artifacts at the site
of Ain Boucherit, located in the High Plateaus of eastern Algeria, from
two distinct strata estimated to be about 1.9 and 2.4 million years-old.
The assemblages contained stone tool manufacturing lithic debris
similar to that recovered from the earliest sites in East Africa.
Additionally, fossil bones, many showing the hallmark V-shaped gouges
and microscopic chipping that suggest butchery and marrow extraction by
stone, were also found. According to the authors, the new findings make
Ain Boucherit the oldest site in northern Africa with in situ evidence
of hominin meat use with associated stone tools and they suggest that
other similarly early sites could be found outside of the Eastern Africa
Rift.
Human ancestors first set foot on the interior of the
Qinghai-Tibetan Plateau around 30,000-40,000 years ago, according to new
research by scientists from the Chinese Academy of Sciences (CAS). This
new finding moves back the earliest data of habitation in the interior
by 20,000 years or more.
The research team was led by Dr. ZHANG Xiaoling and Prof. GAO
Xing from the Institute of Vertebrate Paleontology and Paleoanthropology
(IVPP) of CAS. Their study, published in Science, was based on
investigations of Nwya Devu, the oldest and highest early Stone Age
(Paleolithic) archaeological site known anywhere in the world.
This archaeological achievement is a major breakthrough in our
understanding of the human occupation and evolution of the
Qinghai-Tibetan Plateau as well as larger-scale prehistoric human
migration and exchanges. It caps 60 years of effort trying to find
evidence of the earliest human habitation on the plateau.
The high altitude, atmospheric hypoxia, cold year-round
temperatures and low rainfall of the plateau creates an extremely
challenging environment for human habitation. Archaeological evidence
indicates it was one of the last habitats colonized by Homo sapiens.
Today, the Qinghai-Tibetan Plateau is the third least-populous spot on
the planet.
Before now, no concrete evidence existed of people inhabiting the
interior of the plateau before the Holocene geological epoch
(4,200-11,700 years ago). In addition, only a few reliably dated
Pleistocene (11,700-2.58 million years ago) archaeological sites had
been discovered around the plateau's margins.
The Nwya Devu Paleolithic site discovered by this team confirms
that human ancestors set foot on the Qinghai-Tibet Plateau at elevations
approaching 5,000 meters above sea level around 30,000-40,000 years
ago. It is the first Paleolithic archaeological site discovered in Tibet
that preserves intact stratigraphy allowing age-dating of the site's
antiquity. Nwya Devu is located in the Changthang region of northern
Tibet, about 300 km northwest of Lhasa, the capital of Tibet Autonomous
Region, at about 4,600 meters above sea level.
The site comprises an extensive, dense surface distribution of
stone artifacts and a buried continuous record of human occupation. It
is the earliest Paleolithic site known on the Qinghai-Tibetan Plateau
and the highest yet discovered anywhere in the world. Before this
discovery, the earliest archaeological record of high-altitude human
activity was from the Andean Altiplano, at about 4,480 meters above sea
level, showing human habitation about 12,000 years ago.
This discovery deepens considerably the history of human
occupation of the Qinghai-Tibetan Plateau and the antiquity of human
high-altitude (>4,000 masl) adaptations.
The Late Pleistocene (about 12-000-125,000 years ago) was a
crucial period for human evolution. During that time, the behavior and
cognitive ability of ancient humans developed rapidly and the ability to
adapt to a broader range of environments similarly increased. The
prehistoric cultural artifacts from Nwya Devu provide important
archaeological evidence of the survival strategies of early anatomically
and behaviorally modern people to what is arguably the most rigorous
terrestrial environment on earth. It also allows analysis of Paleolithic
exchange and interactions between East and West suggesting possible
migration routes.
The paper was vetted by three reviewers during the evaluation
process, with one concluding it is " . . . quite original and very
exciting, and will be of utmost interest to the readers of Science
and researchers studying the origin and dispersal of modern humans and
high altitude colonization. The results have profound implications for
the understanding of the timing and dynamics of human settlement of the
Tibetan Plateau."
IMAGE: A - obsidian in rocks formed during the eruption; B, C - obsidian boulders ( "bombs "), differing in color and shape.
view more
Credit: Ekaterina V. Doronicheva et al. / Journal of Archaeological Science: Reports 2018
Research group from Russia and the United States analyzed samples of
obsidian volcanic glass in Kabardino-Balkaria. It turned out that more
than 70 thousand years ago, Neanderthals transferred this mineral to
distances up to 250 kilometers and used it to manufacture tools. These
findings help to understand how populations from different regions
communicated in antiquity. The study was supported by the Russian
Science Foundation and is published in the Journal of Archaeological Science: Reports.
When volcanoes erupted, the ejected lava hardens formed a mixture of
various minerals, including obsidian. In the Stone Age, the ancient
people used this material extensively to create tools. In fact, we use
it even now: in surgery, for the manufacture of dark glass and jewelry.
The elemental composition of obsidian is unique not only for each
volcano, but also for each eruption. This makes it possible to determine
precisely the specific archaeological site, where particular obsidian
sample originated from.
According to earlier studies, in the Paleolithic in Central Europe
and the Caucasus, obsidians were actively transferred from one
settlement to another, and over time the distance of its transportation
increased from 100 to more than 700 kilometers.
Scientists from the non-profit organization "Laboratory of
Prehistory" analyzed the elemental composition of obsidian samples from
various Neanderthals ites of the Central and North-Western Caucasus,
which were found during several expeditions. The obsidian composition
turned out to be almost identical for many tools, which indicates their
common origin. New data also indicates that obsidian was transported
over more than 250 kilometers from sources in the Central Caucasus to
the North-West Caucasus during the Middle Paleolithic. At the same time,
new studies show that the Central Caucasus populations cultural
tradition differed from the Neanderthals of the North-West Caucasus. So
archaeologists have yet to figure out how the interaction between these
different Neanderthals groups was build in this period.
Scientists also found that in the Upper Paleolithic, people
transported obsidians from the Elbrus region and the South Caucasus to
the Mezmay cave, which is located in the North-West Caucasus. The length
of migration was 250 and 450 kilometers respectively. The researchers
suggest that in the Upper Paleolithic there was already a developed
social network between groups of people from different regions.
"The study of cultural areas, the impact of innovations and
mechanisms for the dissemination of new technologies is one of the most
important tasks of modern research. Our work reliably shows the
existence of connections of the population of different regions in
antiquity. These results can be widely used in university lectures, as
well as in modern textbooks for middle and high school. Also, the
results of recent studies can be used in the design of expositions of
museums and thematic exhibitions," summarizes Ekaterina Doronicheva, one
of the authors of the work, Ph.D., research associate of the
"Laboratory of Prehistory".
Researchers from the
Max-Planck-Institute for the Science of Human History and the University
of Helsinki have analyzed the first ancient DNA from mainland Finland.
As described in Nature Communications, ancient DNA was
extracted from bones and teeth from a 3,500 year-old burial on the Kola
Peninsula, Russia, and a 1,500 year-old water burial in Finland. The
results reveal the possible path along which ancient people from Siberia
spread to Finland and Northwestern Russia.
Researchers found the earliest evidence of Siberian ancestry in
Fennoscandia in a population inhabiting the Kola Peninsula, in
Northwestern Russia, dating to around 4,000 years ago. This genetic
ancestry then later spread to populations living in Finland. The study
also found that people genetically similar to present-day Saami people
inhabited areas in much more southern parts of Finland than the Saami
today.
For the present study, genome-wide genetic data from 11 individuals
were retrieved. Eight individuals came from the Kola Peninsula, six from
a burial dated to 3,500 years ago, and two from an 18th to 19th century
Saami cemetery. "We were surprised to find that the oldest samples
studied here had the highest proportion of Siberian ancestry," says
Stephan Schiffels, co-senior author of the study, of the Max Planck
Institute for the Science of Human History.
The other three individuals analyzed for the study came from a water
burial in Levänluhta, Finland. Levänluhta is one of the oldest known
burials in Finland in which human bones have been preserved. The bodies
were buried in what used to be a small lake or a pond, and this seems to
have contributed to exceptionally good preservation of the remains.
Siberian ancestry persists today
The study compared the ancient individuals not only to each other,
but also to modern populations, including Saami, Finnish and other
Uralic language speakers. Among modern European populations, the Saami
have the largest proportion of this ancient Siberian ancestry.
Worldwide, the Nganasan people, from north Siberia, have the largest
proportion of ancient Siberian ancestry.
"Our results show that there was a strong genetic connection between
ancient Finnish and ancient Siberian populations," says Thiseas
Lamnidis, co-first author of the study, "suggesting that ancient
populations from Siberia may have also shared a subsistence strategy,
languages and/or cultural behaviours with Bronze Age and Iron Age Finns,
despite the large geographical distance." Ancient Finnish populations
possibly lived a mobile, nomadic life, trading and moving over a large
range, with far-reaching contacts to other populations.
People found in Levänluhta, Finland, most resemble modern-day Saami
The researchers found that the population in Levänluhta was more
closely related to modern-day Saami people than to the non-Saami Finnish
population today.
"People closely related to the Saami inhabited much more southern
regions of Finland than the Saami do today," explains Kerttu Majander,
co-first author, of the University of Helsinki and the Max Planck
Institute for the Science of Human History. Interestingly, a recent
linguistic study suggested that the place names around Levänluhta trace
back to Saami languages.
"This is the first exploration of ancient DNA from Finland and the
results are very interesting," states Schiffels. "However more ancient
DNA studies from the area will be necessary to better understand whether
the patterns we've seen are representative of Finland as a whole."
The study was conducted as a collaboration between the
SUGRIGE-project (Universities of Helsinki and Turku), and the Max Planck
Institute for the Science of Human History. The archaeological
materials and expertise were provided by the Peter the Great Museum of
Anthropology and Ethnography (Kunstkamera) and the Levänluhta-project
with the Finnish Heritage Agency.
Some of the world's oldest cave
paintings have revealed how ancient people had relatively advanced
knowledge of astronomy. Animal symbols represent star constellations in
the night sky, and are used to mark dates and events such as comet
strikes, analysis from the University of Edinburgh suggests.
Credit: Alistair Coombs
Some of the world's oldest cave paintings have revealed how ancient people had relatively advanced knowledge of astronomy.
The artworks, at sites across Europe, are not simply depictions of
wild animals, as was previously thought. Instead, the animal symbols
represent star constellations in the night sky, and are used to
represent dates and mark events such as comet strikes, analysis
suggests.
They reveal that, perhaps as far back as 40,000 years ago, humans
kept track of time using knowledge of how the position of the stars
slowly changes over thousands of years.
The findings suggest that ancient people understood an effect caused
by the gradual shift of Earth's rotational axis. Discovery of this
phenomenon, called precession of the equinoxes, was previously credited
to the ancient Greeks.
Around the time that Neanderthals became extinct, and perhaps before
humankind settled in Western Europe, people could define dates to within
250 years, the study shows.
The findings indicate that the astronomical insights of ancient
people were far greater than previously believed. Their knowledge may
have aided navigation of the open seas, with implications for our
understanding of prehistoric human migration.
Researchers from the Universities of Edinburgh and Kent studied
details of Palaeolithic and Neolithic art featuring animal symbols at
sites in Turkey, Spain, France and Germany.
They found all the sites used the same method of date-keeping based
on sophisticated astronomy, even though the art was separated in time by
tens of thousands of years.
Researchers clarified earlier findings from a study of stone carvings
at one of these sites -- Gobekli Tepe in modern-day Turkey -- which is
interpreted as a memorial to a devastating comet strike around 11,000
BC. This strike was thought to have initiated a mini ice-age known as
the Younger Dryas period.
They also decoded what is probably the best known ancient artwork --
the Lascaux Shaft Scene in France. The work, which features a dying man
and several animals, may commemorate another comet strike around 15,200
BC, researchers suggest.
The team confirmed their findings by comparing the age of many
examples of cave art -- known from chemically dating the paints used --
with the positions of stars in ancient times as predicted by
sophisticated software.
The world's oldest sculpture, the Lion-Man of Hohlenstein-Stadel
Cave, from 38,000 BC, was also found to conform to this ancient
time-keeping system.
This study was published in Athens Journal of History.
Dr Martin Sweatman, of the University of Edinburgh's School of
Engineering, who led the study, said: "Early cave art shows that people
had advanced knowledge of the night sky within the last ice age.
Intellectually, they were hardly any different to us today.
"These findings support a theory of multiple comet impacts over the
course of human development, and will probably revolutionise how
prehistoric populations are seen."
IMAGE: These artifacts found in China are among
the nearly four dozen that reflect the Levallois technique of
toolmaking. In a paper published Nov. 19 in Nature, researchers date
these artifacts...
view more
Credit: Marwick et al.
New analysis of artifacts found at a South China archaeological site
shows that sophisticated tool technology emerged in East Asia earlier
than previously thought.
A study by an international team of researchers, including from the
University of Washington, determines that carved stone tools, also known
as Levallois cores, were used in Asia 80,000 to 170,000 years ago.
Developed in Africa and Western Europe as far back as 300,000 years ago,
the cores are a sign of more-advanced toolmaking -- the "multi-tool" of
the prehistoric world -- but, until now, were not believed to have
emerged in East Asia until 30,000 to 40,000 years ago.
With the find -- and absent human fossils linking the tools to
migrating populations -- researchers believe people in Asia developed
the technology independently, evidence of similar sets of skills
evolving throughout different parts of the ancient world.
The study is published online Nov. 19 in Nature.
"It used to be thought that Levallois cores came to China relatively recently with modern humans," said Ben Marwick,
UW associate professor of anthropology and one of the paper's
corresponding authors. "Our work reveals the complexity and adaptability
of people there that is equivalent to elsewhere in the world. It shows
the diversity of the human experience."
Levallois-shaped cores -- the "Swiss Army knife of prehistoric
tools," Marwick said -- were efficient and durable, indispensable to a
hunter-gatherer society in which a broken spear point could mean certain
death at the claws or jaws of a predator. The cores were named for the
Levallois-Perret suburb of Paris, where stone flakes were found in the
1800s.
Featuring a distinctive faceted surface, created through a sequence
of steps, Levallois flakes were versatile "blanks," used to spear,
slice, scrape or dig. The knapping process represents a more
sophisticated approach to tool manufacturing than the simpler,
oval-shaped stones of earlier periods.
The Levallois artifacts examined in this study were excavated from
Guanyindong Cave in Guizhou Province in the 1960s and 1970s. Previous
research using uranium-series dating estimated a wide age range of the
archaeological site -- between 50,000 and 240,000 years old -- but that
earlier technique focused on fossils found away from the stone
artifacts, Marwick said. Analyzing the sediments surrounding the
artifacts provides more specific clues as to when the artifacts would
have been in use.
Marwick and other members of the team, from universities in China
and Australia, used optically stimulated luminescence (OSL) to date the
artifacts. OSL can establish age by determining when a sediment sample,
down to a grain of sand, was last exposed to sunlight -- and thus, how
long an artifact may have been buried in layers of sediment.
"Dating for this site was challenging because it had been excavated
40 years ago, and the sediment profile was exposed to air and without
protection. So trees, plants, animals, insects could disturb the
stratigraphy, which may affect the dating results if conventional
methods were used for dating," said Bo Li , an associate professor of
archaeology at the University of Wollongong in Australia and one of the
paper's corresponding authors. "To solve this problem we used a new
single-grain dating technique recently developed in our OSL lab at the
University of Wollongong to date individual mineral grains in the
sediment. Luckily we found residual sediment left over by the previous
excavations, so that allowed us to take samples for dating."
The researchers analyzed more than 2,200 artifacts found at
Guanyindong Cave, narrowing down the number of Levallois-style stone
cores and flakes to 45. Among those believed to be in the older age
range, about 130,000 to 180,000 years old, the team also was able to
identify the environment in which the tools were used: an open woodland
on a rocky landscape, in "a reduced rainforest area compared to today,"
the authors note.
In Africa and Europe these kinds of stone tools are often found at
archaeological sites starting from 300,000 and 200,000 years ago. They
are known as Mode III technology, part of a broad evolutionary sequence
that was preceded by hand-axe technology (Mode II) and followed by blade
tool technology (Mode IV).
Archaeologists thought that Mode IV
technologies arrived in China by migration from the West, but these new
finds suggest they could have been locally invented. At the time people
were making tools in Guanyindong Cave, the Denisovans -- ancestors to
Homo sapiens and relative contemporaries to Neandertals elsewhere in the
world -- roamed East Asia. But while hundreds of fossils of archaic
humans and related artifacts, dating as far back as more than 3 million
years ago, have been found in Africa and Europe, the archaeological
record in East Asia is sparser.
That's partly why a stereotype exists, that ancient peoples in the
region were behind in terms of technological development, Marwick said.
"Our work shows that ancient people there were just as capable of
innovation as anywhere else. Technological innovations in East Asia can
be homegrown, and don't always walk in from the West," he said.
The independent emergence of the Levallois technique at different
times and places in the world is not unique in terms of prehistoric
innovations. Pyramid construction, for one, appeared in at least three
separate societies: the Egyptians, the Aztecs and the Mayans.
Boatbuilding began specific to geography and reliant on a community's
available materials. And writing, of course, developed in various forms
with distinct alphabets and characters.
In the evolution of tools, Levallois cores represent something of a
middle stage. Subsequent manufacturing processes yielded more-refined
blades made of rocks and minerals that were more resistant to flaking,
and composites that, for example, combined a spear point with blades
along the edge. The appearance of blades later in time indicates a
further increase in the complexity and the number of steps required to
make the tools.
"The appearance of the Levallois strategy represents a big increase
in the complexity of technology because there are so many steps that
have to work in order to get the final product, compared to previous
technologies," Marwick said.
The results show significant
morphological differences pointing to a respiratory mechanism that was
different compared with that of modern humans
University of the Basque Country
IMAGE: This is an image of the reconstruction of the thorax of Kebara 2. Scale = 5 cm.
view more
Credit: A. Gómez-Olivencia, A. Barash and E. Been
Neanderthals were hunter-gatherers who inhabited western Eurasia for
more than 200 thousand years during glacial as well as interglacial
periods until they became extinct around 40 thousand years ago. While
some of the anatomical regions of these extinct humans are well known,
others, such as the vertebral column and the ribs, are less well known
because these elements are more fragile and not well preserved in the
fossil record. In 1983 a partial Neanderthal skeleton (known officially
as Kebara 2, and nicknamed "Moshe") belonging to a young male
Neanderthal individual who died some 60,000 years ago was found in the
Kebara site (Mount Carmel, Israel). While this skeleton does not
preserve the cranium because some time after burial the cranium was
removed, probably as a consequence of a funerary ritual. However, all
the vertebrae and ribs are preserved, and so are other fragile
anatomical regions, such as the pelvis or the hyoid bone (a bone in the
neck to which some of the tongue muscles are attached). So it is the
skeleton that preserves the most complete thorax in the fossil record.
New statistical and virtual reconstruction methods have enabled the
researchers to extract new information, which has just been published in
the prestigious journal Nature Communications.
For over 150 years, Neanderthal remains have been found at many
sites in Europe and Western Asia (including the Middle East), and the
thorax morphology of this human species has been a subject of debate
since 1856, when the first ribs belonging to this human group were
found. Over the past decade, virtual reconstructions have become a new
tool that is increasingly being used in fossil study. This methodology
is particularly useful with fragile fossils, such as the vertebra and
ribs that form the thorax. Nearly two years ago, the same research team
created a reconstruction of the spine of this Neanderthal individual; it
displays the preserved spine of Kebara 2 showing less pronounced curves
in these humans when compared with Homo sapiens. The team's paper,
published in the book "Human Paleontology and Prehistory," pointed to a
straighter spine than that of modern humans.
For this virtual model of the thorax, researchers used both direct
observations of the Kebara 2 skeleton, currently housed at Tel Aviv
University, and medical CT (computerized axial tomography) scans of the
vertebrae, ribs and pelvic bones. Once all the anatomical elements had
been assembled, the virtual reconstruction was done by means of 3D
software specifically designed for this purpose. "This was meticulous
work," said Alon Barash of Bar Ilan University in Israel. "We had to
scan each vertebra and all of the rib fragments individually and then
reassemble them in virtual 3D."
"In the reconstruction process, it was necessary to virtually 'cut'
and realign some of the parts that displayed deformation, and
mirror-image the ribs that had been best preserved in order to
substitute the poorly preserved ones on the other side," said Asier
Gómez-Olivencia, an Ikerbasque research fellow at the University of the
Basque Country.
"The differences between the thorax of a Neanderthal and of a modern
human are striking," said Daniel García-Martínez and Markus Bastir,
researchers at the National Museum of Natural Sciences (MNCN-CSIC) and
co-authors of the work. "The Neanderthal spine is located more inside
the thorax with respect to the ribs, which provides more stability. The
thorax is also wider in its lower part," added Mikel Arlegi (UPV/EHU).
"The wider lower thorax of Neanderthals and the more horizontal
orientation of the ribs, as shown in its reconstruction, suggest that
Neanderthals relied more on the diaphragm for breathing," said Ella Been
of the Ono Academic College. "Modern humans rely on both the diaphragm
and on the expansion of the rib cage. Here we can see how new
technologies and methodologies in the study of fossil remains are
providing new information to understand extinct species."
This new information is consistent with the recent works on the
larger lung capacity of Neanderthals published by two of the co-authors
of this study, Markus Bastir and Daniel García-Martínez (Virtual
Anthropology Laboratory of the MNCN), in which they support the presence
of greater lung capacity in the Neanderthals.).
Patricia Kramer of the University of Washington sums it all up
thus: "This is the culmination of 15 years of research into the
Neanderthal thorax; we hope that future genetic analyses will provide
additional clues about the respiratory physiology of the Neanderthals".
IMAGE: Chuckie Barnett at age 3 (left) and Michael Barnett at age 5.
view more
Credit: Marsha Barnett
Over 30 years ago, Marsha and Allen Barnett lost their sons to a
puzzling childhood disease that relentlessly attacked their nervous
systems and sapped their energy. After five-year-old Chuckie died
suddenly in 1981, doctors provided a name for the disease: Leigh
syndrome. Leigh syndrome is a complex disorder typically caused by dysfunctional mitochondria,
the tiny batteries inside all cells that generate our energy. Two years
later, the same disease killed Michael, Chuckie's older brother, when
he was 10 years old.
Earlier this year, Mrs. Barnett, who lives in southeastern
Pennsylvania, received a phone call from a physician she knew, Marni J.
Falk, MD, at Children's Hospital of Philadelphia (CHOP),
where Barnett has long supported research in mitochondrial medicine.
"She asked about Chuckie's and Michael's symptoms, then told me, 'I
think we found the causal gene mutation,'" she said.
Falk, the Executive Director of CHOP's Mitochondrial Medicine Frontier Program,
led a research team that identified the inherited mutation in the
Barnett family, a change in one nuclear gene that arose spontaneously
generations ago among both parents' Ashkenazi Jewish ancestors. Scores
of different genes harbor mutations that may cause Leigh syndrome, by
many different possible inheritance patterns. The mutation in this
family was present on both copies of the same gene in both affected
brothers, and was also seen in two other children in the study with
Leigh syndrome who were not related to them.
The study team, a research collaboration involving multiple centers
to prove that the gene mutation definitely impaired mitochondrial
function, published its findings in the October 2018 issue of Human Molecular Genetics.
Falk's co-study leader was Michio Hirano, MD, of Columbia University,
and the study's co-first authors were Rebecca D. Ganetzky, MD, of CHOP,
and Emanuele Barca, PhD, of Columbia University.
Leigh syndrome, named after a British neuropsychologist who first
described it in 1951, involves metabolic strokes deep in the brain, with
a loss of skills from stressors such as fever, illness and anesthesia.
It has historically had a high mortality rate in childhood or
adolescence. Over 90 different genes necessary for mitochondria to
function properly are now known to cause it, with disease-causing gene
variants rooted in DNA, either within a cell's nucleus or in the
separate mitochondrial genome.
Impaired cellular energy production in Leigh syndrome causes
patients to experience progressive weakening of their muscles, heart and
central nervous system. Both Chuckie and Michael eventually lost
control of their eye muscles, for instance.
Falk and colleagues analyzed data from four subjects affected with
Leigh syndrome who did not have a specific genetic diagnosis: the
Barnett boys and two unrelated patients from Ashkenazi families now
living with Leigh syndrome who are followed by the CHOP Mitochondrial
Medicine Frontier Program. The team identified a common causative
mutation in the nuclear gene USMG5, a gene not previously associated with any human disease. USMG5
encodes a protein component of complex V, the molecular motor within
the mitochondrial energy system that directly generates ATP, each cell's
chemical energy currency.
The change in USMG5 is a founder mutation, one that
originated by chance, most likely centuries ago in an unidentified
individual from an Ashkenazi Jewish population, possibly in Eastern
Europe. The mutation causes an autosomal recessive disease, so someone
can carry the mutation in one of their pair of USMG5 genes
without having disease symptoms. However, if both parents are mutation
carriers--as is true of Marsha and Allen--each child has a 25 percent
chance of inheriting the mutation on both copies of their gene, and
being affected with Leigh syndrome. The youngest Barnett son, now 40
years old, does not have Leigh syndrome.
Nearly 30 years ago Marsha and Allen Barnett established a
foundation to support research in mitochondrial disease, which
subsequently supported the recruitment to CHOP of mitochondrial medicine
pioneer Douglas C. Wallace, PhD, where he established the Center for
Mitochondrial and Epigenomic Medicine in 2010. Wallace holds the Michael
and Charles Barnett Endowed Chair in Pediatric Mitochondrial Medicine
and Metabolic Disease.
Insights from the current research have implications for preventive medicine and genetic counseling, says Falk. The USMG5
mutation should be added to the list of mutations tested for at the
time of prenatal genetic carrier screening in prospective Ashkenazi
Jewish parents. The mutation is relatively common in the Ashkenazi
population, where roughly one in 175 individuals are carriers. It should
also be added to the list of genes to be evaluated in children with
Leigh syndrome.
"What we've learned from these four children recognized to suffer from USMG5
deficiency will enable future children diagnosed with this condition to
be very carefully monitored and managed when they face stressors such
as fever or anesthesia, to avoid decompensation," said Falk.
Decompensation is a rapid medical deterioration that may occur when a
patient's system is stressed. In the longer run, Falk and other
researchers are working to realize precision medicines for mitochondrial
disease. In the future, children known to have this gene disorder may
be able to receive treatments targeted to their specific disease.
"This work highlights the importance to families and medicine of
continuing to work to solve cases that have never before been fully
understood," says Falk. "The current revolution in genomic sequencing
methods, combined with highly collaborative research investigations to
validate genetic leads, continues to deepen our knowledge of
mitochondrial disease, and with it, precision diagnosis, counseling,
management, and therapies."
Nearly a thousand years ago, a famous king created
a famous book, later given the title "Domesday" (pronounced
"doomsday").
At least that's been the common story: William the Conqueror, 20
years after his 1066 invasion of England from Normandy, ordered a
massive survey of his new realm. One year later, he got a book with the
results - a record of the nation's wealth and resources, everything from
property to sheep to servants.
The "Great Domesday Book," as it was later named, is perhaps the most famous document in English history after the Magna Carta.
The book's origin story, however, had not been thoroughly
investigated until University of Illinois history professor Carol Symes
took up the task. "What had never been resolved is how this massive text
was really created," Symes said, "and in this incredibly narrow
timeframe."
Now, after years of research, Symes makes the case in the journal Speculum
that the final "Great Domesday Book" came years and perhaps decades
later than the 1087 date to which it's attributed, also the year of
William's death.
It also was not the orderly bureaucratic enterprise that's often
assumed, but instead "enabled hundreds of thousands of individuals and
communities to air grievances and to make their own ideas of law and
justice a matter of public record," Symes wrote.
"This is documentation of the trauma of conquest. We're watching
people pushing back, or at least letting their voices be heard because
they're fed up," she said. In one example, the text records townspeople
bitterly complaining about the leveling of houses to build a castle.
"We need to rethink what has seemed to be a rather straightforward,
top-down royal project, but is revealed to be the tip of a big,
monstrous iceberg that involves the agency of many historical actors and
often preserves their voices. This helps to tell a very different story
about one of the landmark events of England - the Norman conquest and
its aftermath - that is not just a story about 'the great man.'"
The universe of the "Domesday Book" is complicated, to say the least.
The name is attached to two different bodies of text, "Great Domesday"
and "Little Domesday" - the first covering all of the country's shires
except three in the southeast, the second covering those three, but in
more detail, suggesting it was an earlier draft.
There's also "Exeter Domesday," a collection of 103 booklets that
appears to be an even earlier draft of survey results, mostly covering
three shires in the southwest.
Curiously, London does not appear in any of these records, which likely
is a sign its citizens either ignored the inquest or overwhelmed it with
grievances, Symes said.
The Exeter collection is just one of many "satellite" documents that
have some connection with the survey or book but have received little
scholarly attention, Symes said. For many who focus their research on
"Great Domesday," the book has been "the sun around which everything
else spins."
Among Symes' contributions is to suggest ways that the different
texts relate to each other, since that hasn't been clear. "I think I
have figured out the workings behind how this book ("Great Domesday")
was made," she said.
Most of Symes' research focused on the Exeter collection and another
satellite document, a small fragment of parchment roll, perhaps the
oldest in England, from an abbey at Burton-on-Trent in the northwest of
the country. In both cases, she examined the original documents.
The Exeter documents provide numerous clues on how "Great Domesday"
was assembled, but also serve as a window on the people and the process.
A bishop can be seen intervening with the king's advisers when his
property is not recorded. Teenage scribes make drinking plans in the
marginal notes of manuscripts.
The abbey's parchment fragment, however, is key to Symes' contention
that the final book came years and even decades later. She ties its
contents to the comings and goings of a man who served at one time as
its abbot, who had access to the survey data that went into "Domesday"
and may even have been involved in the survey.
"It plugs a huge hole that we had in our evidence. It suggests that
the process of creating the thing we call 'Great Domesday' actually took
a lot longer than people had thought."
Symes said she was attracted to this particular book as part of her
interest in medieval manuscripts, especially the complex ways in which
they were "mediated" - i.e., written, handled, copied, recopied, added
to, edited, interpreted and heard by audiences, all in an age before the
printing press. Historians need to take a text's complex mediation into
account, she said, even considering the parchment on which it was
written, to fully understand and not misinterpret it.
Symes also likes messiness - finding out "how the sausage gets made."
She was attracted to Domesday, in part, "because it's a messy document
that people pretend is not messy. It's taken to be this pristine,
transparent thing when it's not."
One value in the Domesday research, she said, is in "realizing that
the people of almost a thousand years ago were real people with real
human emotions and needs. We're putting on a different set of glasses to
look at these sources, and what we see is all those people who were
written out of the record. We're getting to see and hear them again."
The "wonderful irony," Symes said, is that we can do that through
one of the most famous books created in the Middle Ages, by a king.
More than 4,000 years ago, the Harappa culture thrived in the Indus
River Valley of what is now modern Pakistan and northwestern India,
where they built sophisticated cities, invented sewage systems that
predated ancient Rome's, and engaged in long-distance trade with
settlements in Mesopotamia. Yet by 1800 BCE, this advanced culture had
abandoned their cities, moving instead to smaller villages in the
Himalayan foothills.
A new study from the Woods Hole Oceanographic
Institution (WHOI) found evidence that climate change likely drove the
Harappans to resettle far away from the floodplains of the Indus.
Beginning in roughly 2500 BCE, a shift in temperatures and
weather patterns over the Indus valley caused summer monsoon rains to
gradually dry up, making agriculture difficult or impossible near
Harappan cities, says Liviu Giosan, a geologist at WHOI and lead author
on the paper that published Nov. 13, 2018, in the journal Climate of the Past.
"Although fickle summer monsoons made agriculture difficult along
the Indus, up in the foothills, moisture and rain would come more
regularly," Giosan says. "As winter storms from the Mediterranean hit
the Himalayas, they created rain on the Pakistan side, and fed little
streams there. Compared to the floods from monsoons that the Harappans
were used to seeing in the Indus, it would have been relatively little
water, but at least it would have been reliable."
Evidence for this shift in seasonal rainfall--and the Harapans'
switch from relying on Indus floods to rains near the Himalaya in order
to water crops--is difficult to find in soil samples. That's why Giosan
and his team focused on sediments from the ocean floor off Pakistan's
coast. After taking core samples at several sites in the Arabian Sea, he
and his group examined the shells of single-celled plankton called
foraminifera (or "forams") that they found in the sediments, helping
them understand which ones thrived in the summer, and which in winter.
Once he and the team identified the season based on the forams'
fossil remains, they were able to then focus on deeper clues to the
region's climate: paleo-DNA, fragments of ancient genetic material
preserved in the sediments.
"The seafloor near the mouth of the Indus is a very low-oxygen
environment, so whatever grows and dies in the water is very well
preserved in the sediment," says Giosan. "You can basically get
fragments of DNA of nearly anything that's lived there."
During winter monsoons, he notes, strong winds bring nutrients from
the deeper ocean to the surface, feeding a surge in plant and animal
life. Likewise, weaker winds other times of year provide fewer
nutrients, causing slightly less productivity in the waters offshore.
"The value of this approach is that it gives you a picture of the
past biodiversity that you'd miss by relying on skeletal remains or a
fossil record. And because we can sequence billions of DNA molecules in
parallel, it gives a very high-resolution picture of how the ecosystem
changed over time," adds William Orsi, paleontologist and geobiologist
at Ludwig Maximilian University of Munich, who collaborated with Giosan
on the work.
Sure enough, based on evidence from the DNA, the pair found that
winter monsoons seemed to become stronger--and summer monsoons
weaker--towards the later years of the Harappan civilization,
corresponding with the move from cities to villages.
"We don't know whether Harappan caravans moved toward the foothills
in a matter of months or this massive migration took place over
centuries. What we do know is that when it concluded, their urban way of
life ended," Giosan says.
The rains in the foothills seem to have been enough to hold the
rural Harapans over for the next millennium, but even those would
eventually dry up, likely contributing to their ultimate demise.
"We can't say that they disappeared entirely due to climate--at the
same time, the Indo-Aryan culture was arriving in the region with Iron
Age tools and horses and carts. But it's very likely that the winter
monsoon played a role," Giosan says.
The big surprise of the research, Giosan notes, is how far-flung the
roots of that climate change may have been. At the time, a "new ice
age" was settling in, forcing colder air down from the Arctic into the
Atlantic and northern Europe. That in turn pushed storms down into the
Mediterranean, leading to an upswing in winter monsoons over the Indus
valley.
"It's remarkable, and there's a powerful lesson for today," he
notes. "If you look at Syria and Africa, the migration out of those
areas has some roots in climate change. This is just the beginning--sea
level rise due to climate change can lead to huge migrations from low
lying regions like Bangladesh, or from hurricane-prone regions in the
southern U.S. Back then, the Harappans could cope with change by moving,
but today, you'll run into all sorts of borders. Political and social
convulsions can then follow."
UNM researchers part of discovery of ancient ancestry linking two continents
University of New Mexico
IMAGE: Excavation in progress at the rock shelter
site of Lapa do Santo in Brazil, where an individual dating to
approximately ~9,600 years ago was found.
view more
Credit: André Strauss
The first high quality ancient DNA data from Central and South
America--49 individuals some as old as 11,000 years--has revealed a
major and previously unknown exchanges between populations.
Unprecedented details about the ancestry of the people of Central
and South America have been uncovered in a new study in the journal Cell
by archaeologists and geneticists at The University of New Mexico,
Harvard Medical School, the Howard Hughes Medical Institute, the Max
Planck Institute for the Science of Human History, the University of
California Santa Cruz, the Pennsylvania State University, the University
of São Paulo, and other institutions in Brazil, Belize, Chile,
Argentina, Peru, the European Union and the U.S.
The researchers analyzed DNA data from precisely dated skeletons
found in excavations in Central and South America. Some of these people
were over 10,000 years old. Previously, the only genomes that had been
reported from this region and that provided sufficient quality data to
analyze were less than 1,000 years old.
After obtaining official permits to excavate, the researchers
conducted analysis on ancient human remains, and consulted with local
governmental agencies and indigenous organizations.
By comparing ancient and modern genomes from the Americas and other
parts of the globe, they were able to obtain qualitatively new insights
into the early history of Central and South America.
University of New Mexico Anthropology Professor Keith Prufer and his
colleagues from Pennsylvania State and Exeter University (UK)
contributed the Central American component of this unprecedented study
as part of an NSF and Alphawood Foundation funded project studying the
earliest humans to settle in the American tropics.
Prufer led excavations in Belize where the they recovered three of
the oldest skeletons from the region, all with well-preserved DNA.
This UNM project focuses on early human adaptations in remote
tropical rainforests in the Americas. The data from these excavations
are reshaping how researchers view Early Holocene relationships between
humans living in North, Central, and South America. Link between a Clovis culture-associated individual and the oldest Central and South Americans
"A key discovery was that a Clovis culture-associated individual
from North America dating to around 12,800 years ago shares distinctive
ancestry with the oldest Chilean, Brazilian and Belizean individuals,"
explains co-lead author Cosimo Posth of the Max Planck Institute for the
Science of Human History. "This supports the hypothesis that the
expansion of people who spread the Clovis culture in North America also
reached Central and South America."
These individuals from Chile, Brazil and Belize date to more than
9,000 years ago. However, younger individuals and present-day people in
South America do not share the Clovis culture-associated ancestry that
characterizes the oldest individuals. Says co-senior author David Reich
from Harvard Medical School and the Howard Hughes Medical Institute,
"This is our second key discovery: we have shown that there was a
continent-wide population replacement that began at least 9,000 years
ago."
According to Prufer, there are many remarkable aspects to this research finding.
"For the first time, we have archaeological and genetic evidence
linking some of the oldest humans in Central America to the earliest
known populations to arrive in the New World, and clear indications of
an early relationship between this region and South America," says
Prufer. "It is also a testament to the power of interdisciplinary
research involving archaeologists and geneticists and how it is
revolutionizing the study of ancient humans." The promise of ancient DNA research in the Americas
The researchers emphasize that their study gives only a glimpse of
the discoveries that may come through future work. To learn about the
initial movements of people into Central and South America, it would be
necessary to obtain ancient DNA from individuals dating to before 11,000
years ago.
Additionally, even for the period between 11,000 and 3,000 years ago
that is best covered in this study the picture is far from complete.
"We lacked ancient data from Amazonia, northern South America and
the Caribbean, and thus cannot determine how individuals in these
regions relate to the ones we analyzed," explains Reich. "Filling in
these gaps should be a priority for future work."
"We are excited about the potential of research in this area,"
states co-senior author Johannes Krause of the Max Planck Institute for
the Science of Human History. "With future, regionally focused studies
with large sample sizes, we could realize the potential of ancient DNA
to reveal how the human diversity of this region came to be the way it
is today."
Stone tools from the Middle Stone Age
in South Africa shows that different communities were connected over
long time periods over vast geographical areas.
University of the Witwatersrand
IMAGE: This is an overview of the Klipdrift Complex from sea.
view more
Credit: Magnus Haaland
The tools - mainly blades and backed knives from the Howiesons Poort -
were found in various layers in the Klipdrift Shelter, in the southern
Cape in South Africa. They were examined by a group of lithic experts,
who found distinct similarities to tools from sites in South Africa's
Western Cape, over 300km away, in particular with the Diepkloof Rock
Shelter site.
"While regional specificities in the tools from the various sites
exist, the similarities of Klipdrift Shelter with the site of Diepkloof
Rock Shelter are astonishing," says Dr Katja Douze, the corresponding
author of the study that was published in PLOS ONE on November
7. Douze is a researcher at the laboratory of Archaeology and
Populations in Africa at the University of Geneva, Switzerland. Douze
was a post-doctoral fellow at the Center of Excellence in Palaeosciences
at the Evolutionary Studies Institute, at University of the
Witwatersrand (Wits), at the time of the study. She led the analysis
together with Dr Anne Delagnes, Research Director at the French National
Center for Research (CNRS) and director of the laboratory PACEA, at the
University of Bordeaux, and with Dr Sarah Wurz, Associate professor at
the School of Geography, Archaeology and Environmental Sciences,
University of the Witwatersrand and also associated with the DST/NRF
SARChI Chair in The Origins of Modern Human Behaviour and the SapienCE -
Centre for Early Sapiens Behaviour (SFF CoE).
The team, under the leadership of Professor Christopher Henshilwood
from Wits University and the University of Bergen's SapienCE Centre for
Early Sapiens Behaviour, examined thousands of stone tools that were
excavated from seven layers that represent a time period of between 66
000 years ago and 59 000 years ago, to establish the differences in
stone tool design over time. They then also compared the stone tools to
various other sites in Howiesons Poort.
"The site of Klipdfrift Shelter is one of the few containing a long
archaeological sequence that provides data on cultural changes over time
during the Howiesons Poort," says Douze. "This makes it perfect to
study the change in culture over time."
However, what was even more exciting for the researchers was the
fact that for the first time they could show closely networked
interaction between distant communities through the way they designed
stone tools.
"There was an almost perfect match between the tools from the
Klipdrift and Diepkloof shelters," says Douze. "This shows us that there
was regular interaction between these two communities."
"This is the first time that we can draw such a parallel between
different sites based on robust sets of data, and show that there was
mobility between the two sites. This is unique for the Middle Stone
Age," says Douze.
The Middle Stone Age in Africa stretches from 350 000 years ago to
25 000 years ago and is a key period for understanding the development
of the first Homo sapiens, their behavioral changes through time and
their movements in-and-out of Africa.
Named after Howieson's Poort Shelter archeological site near
Grahamstown in South Africa, the Howiesons Poort is a specific
techno-culture within the Middle Stone Age that evolves in southern
Africa after 100 000 years ago at the Diepkloof Shelter, but between 66
000 - 59 000 years at most other Howiesons Poort sites. The
characteristics of the Howiesons Poort are strongly distinctive from
other Middle Stone Age industries as it is characterised by the
production of small blades and backed tools, used as hunting armatures
as much as for cutting flesh, while other MSA industries show flake,
large blade and point productions.
The tools found in the deeper layers of the Klipdrift Shelter that
represent the earlier phases of the Howiesons Poort were found to be
made from heat-treated silcrete, while those from later phases were made
from less homogeneous rocks such as quartz and quartzite. This change
happens together with changes in tool production strategies. "The
changes over time seems to reflect cultural changes, rather than
immediate alterations forced on the designers by changes in climate",
says Douze.
"Our preconceived idea of prehistoric groups is that they just
struggled to survive, but in fact they were very adaptable to
environmental circumstances. There seem to be no synchrony between
modification in design choices and environmental changes. However, the
aridification of the area over time might have led to a very gradual
change that led to the end of the Howiesons Poort."
The team also attempted to establish why and how the Howiesons Poort
ended, and to see whether it came to a sudden, or gradual end.
"The decline of the Howiesons Poort at Klipdrift Shelter shows a
gradual and complex pattern of changes, from which the first "symptoms"
can be observed much earlier than the final abandonment of typical
Howiesons Poort technology and toolkits," says Douze.
"This does not support a catastrophic scenario involving alarming
demographic drops or massive population replacements. The fact that a
similar pattern of gradual change has been described for at least three
other southern African Howiesons Poort sites (Rose Cottage Cave,
Diepkloof Rock Shelter and Klasies River main site), further ascertains
convergent evolutions in cultural trajectories rather than isolated
groups promptly reacting to locally determined pressures."
Study by 72 researchers from eight
countries concludes that the Lagoa Santa people are descendants of
Clovis culture migrants from North America; distinctly African features
attributed to Luzia were wrong
Fundação de Amparo à Pesquisa do Estado de São Paulo
IMAGE: Study by 72 researchers from eight
countries concludes that the Lagoa Santa people are descendants of
Clovis culture migrants from North America. Distinctly African features
attributed to Luzia were wrong
view more
Credit: André Strauss e Caroline Wilkinson
The history of the peopling of the Americas has just been
interpreted afresh. The largest and most comprehensive study ever
conducted on the basis of fossil DNA extracted from ancient human
remains found on the continent has confirmed the existence of a single
ancestral population for all Amerindian ethnic groups, past and present.
Over 17,000 years ago this original contingent crossed the Bering
Strait from Siberia to Alaska and began peopling the New World. Fossil
DNA shows an affinity between this migratory current and the populations
of Siberia and northern China. Contrary to the traditional theory it
had no link to Africa or Australasia.
The new study also reveals that once they had settled in North
America the descendants of this ancestral migratory flow diversified
into two lineages some 16,000 years ago.
The members of one lineage crossed the Isthmus of Panama and peopled South America in three distinct consecutive waves.
The first wave occurred between 15,000 and 11,000 years ago. The
second took place at most 9,000 years ago. There are fossil DNA records
from both migrations throughout South America. The third wave is much
more recent but its influence is limited as it occurred 4,200 years ago.
Its members settled in the Central Andes.
An article on the study has just been published in the journal Cell
a group of 72 researchers from eight countries, affiliated with the
University of São Paulo (USP) in Brazil, Harvard University in the
United States, and Max Planck Institute for the Science of Human History
in Germany, among others.
According to the researchers' findings, the lineage that made the
north-south journey between 16,000 and 15,000 years ago belonged to the
Clovis culture, named for a group of archeological sites excavated in
the western US and dating from 13,500-11,000 years ago.
The Clovis culture was so named when flint spearheads were found in
the 1930s at a dig in Clovis, New Mexico. Clovis sites have been
identified throughout the US and in Mexico and Central America. In North
America, the Clovis people hunted Pleistocene megafaunas such as giant
sloth and mammoth. With the decline of the megafauna and its extinction
11,000 years ago, the Clovis culture eventually disappeared. Long before
that, however, bands of hunter-gatherers had traveled south to explore
new hunting grounds. They ended up settling in Central America, as
evidenced by 9,400-year-old human fossil DNA found in Belize and
analyzed in the new study.
At a later date, perhaps while pursuing herds of mastodons, Clovis
hunter-gatherers crossed the Isthmus of Panama and spread into South
America, as evidenced by genetic records from burial sites in Brazil and
Chile revealed now. This genetic evidence corroborates well-known
archeological finds such as the Monte Verde site in southern Chile,
where humans butchered mastodons 14,800 years ago.
Among the many known Clovis sites, the only burial site associated
with Clovis tools is in Montana, where the remains of a baby boy
(Anzick-1) were found and dated to 12,600 years ago. DNA extracted from
these bones has links to DNA from skeletons of people who lived between
10,000 and 9,000 years ago in caves near Lagoa Santa, Minas Gerais
State, Brazil. In other words, the Lagoa Santa people were partial
descendants of Clovis migrants from North America.
"From the genetic standpoint, the Lagoa Santa people are descendants of the first Amerindians," said archeologist André Menezes Strauss,
who coordinated the Brazilian part of the study. Strauss is affiliated
with the University of São Paulo's Museum of Archeology and Ethnology
(MAE-USP).
"Surprisingly, the members of this first lineage of South Americans
left no identifiable descendants among today's Amerindians," he said.
"Some 9,000 years ago their DNA disappears completely from the fossil
samples and is replaced by DNA from the first migratory wave, prior to
the Clovis culture. All living Amerindians are descendants of this first
wave. We don't yet know why the genetic stock of the Lagoa Santa people
disappeared."
One possible reason for the disappearance of DNA from the second
migration is that it was diluted in the DNA of the Amerindians who are
descendants of the first wave and cannot be identified by existing
methods of genetic analysis.
According to Tábita Hünemeier,
a geneticist at the University of São Paulo's Bioscience Institute
(IB-USP) who took part in the research, "one of the main results of the
study was the identification of Luzia's people as genetically related to
the Clovis culture, which dismantles the idea of two biological
components and the possibility that there were two migrations to the
Americas, one with African traits and the other with Asian traits".
"Luzia's people must have resulted from a migratory wave originating
in Beringia," she said, referring to the now-submerged Bering land
bridge that joined Siberia to Alaska during the glaciations, when sea
levels were lower.
"The molecular data suggests population substitution in South
America since 9,000 years ago. Luzia's people disappeared and were
replaced by the Amerindians alive today, although both had a common
origin in Beringia," Hünemeier said. Brazilian contribution
The Brazilian researchers' contribution to the study was
fundamental. Among the 49 individuals from which fossil DNA was taken,
seven skeletons dated to between 10,100 and 9,100 years ago came from
Lapa do Santo, a rock shelter in Lagoa Santa.
The seven skeletons, alongside dozens of others, were found and
exhumed in successive archeological campaigns at the site, led initially
by Walter Alves Neves,
a physical anthropologist at IB-USP, and since 2011 by Strauss. The
archeological campaigns led by Neves between 2002 and 2008 were funded
by São Paulo Research Foundation - FAPESP.
Altogether the new study investigated fossil DNA from 49 individuals
found at 15 archeological sites in Argentina (two sites, 11 individuals
dated to between 8,900 and 6,600 years ago), Belize (one site, three
individuals dated to between 9,400 and 7,300 years ago), Brazil (four
sites, 15 individuals dated to between 10,100 and 1,000 years ago),
Chile (three sites, five individuals dated to between 11,100 and 540
years ago) and Peru (seven sites, 15 individuals dated to between 10,100
and 730 years ago).
The Brazilian skeletons come from the archeological sites Lapa do
Santo (seven individuals dated to about 9,600 years ago), Jabuticabeira
II in Santa Catarina State (a sambaqui or shell midden with five
individuals dated to about 2,000 years ago), as well as from two river
middens in the Ribeira Valley, São Paulo State: Laranjal (two
individuals dated to about 6,700 years ago), and Moraes (one individual
dated to about 5,800 years ago). Paulo Antônio Dantas de Blasis, an archeologist affiliated with MAE-USP, led the dig at Jabuticabeira II, which was also supported by FAPESP through a Thematic Project.
The digs at the river midden sites in São Paulo State were led by Levy Figuti, also an archeologist at MAE-USP, and were also supported by FAPESP.
"The Moraes skeleton (5,800 years old) and the Laranjal skeleton
(6,700 years old) are among the most ancient from the South and
Southeast of Brazil," Figuti said. "These locations are strategically
unique because they're between the highlands of the Atlantic plateau and
the coastal plain, contributing significantly to our understanding of
how the Southeast of Brazil was peopled."
These skeletons were found between 2000 and 2005. From the start,
they presented a complex mixture of coastal and inland cultural traits,
and the results of their analysis generally varied except in the case of
one skeleton diagnosed as Paleoindian (analysis of its DNA is not yet
complete).
"The study that's just been published represents a major step
forward in archeological research, exponentially increasing what we knew
until only a few years ago about the archaeogenetics of the peopling of
the Americas," Figuti said.
Hünemeier has also recently made a significant contribution to the
reconstruction of human history in South America using paleogenomics. Amerindian genetics
Not all the human remains found at some of the most ancient
archeological sites in Central and South America belonged to genetic
descendants of the Clovis culture. The inhabitants of several sites did
not have Clovis-associated DNA.
"This shows that besides its genetic contribution the second
migration wave to South America, which was Clovis-associated, may also
have brought with it technological principles that would be expressed in
the famous fishtail points that are found in many parts of South
America," Strauss said.
How many human migrations from Asia came to the Americas at the end
of the Ice Age more than 16,000 years ago was hitherto unknown. The
traditional theory, formulated in the 1980s by Neves and other
researchers, was that the first wave had African traits or traits
similar to those of the Australian Aboriginals.
The well-known forensic facial reconstruction of Luzia was performed
in accordance with this theory. Luzia is the name given to the fossil
skull of a woman who lived in the Lagoa Santa region 12,500 years ago
and is sometimes referred to as the "first Brazilian".
The bust of Luzia with African features was built on the basis of
the skull's morphology by British anatomical artist Richard Neave in the
1990s.
"However, skull shape isn't a reliable marker of ancestrality or
geographic origin. Genetics is the best basis for this type of
inference," Strauss explained.
"The genetic results of the new study show categorically that there
was no significant connection between the Lagoa Santa people and groups
from Africa or Australia. So the hypothesis that Luzia's people derived
from a migratory wave prior to the ancestors of today's Amerindians has
been disproved. On the contrary, the DNA shows that Luzia's people were
entirely Amerindian."
A new bust has replaced Luzia in the Brazilian scientific pantheon.
Caroline Wilkinson, a forensic anthropologist at Liverpool John Moores
University in the UK and a disciple of Neave, has produced a facial
reconstruction of one of the individuals exhumed at Lapa do Santo. The
reconstruction was based on a retrodeformed digital model of the skull.
"Accustomed as we are to the traditional facial reconstruction of
Luzia with strongly African features, this new facial reconstruction
reflects the physiognomy of the first inhabitants of Brazil far more
accurately, displaying the generalized and indistinct features from
which the great Amerindian diversity was established over thousands of
years," Strauss said.
The study published in Cell, he added, also presents the first genetic data on Brazilian coastal sambaquis.
"These monumental shell mounds were built some 2,000 years ago by
populous societies that lived on the coast of Brazil. Analysis of fossil
DNA from shell mound burials in Santa Catarina and São Paulo shows
these groups were genetically akin to the Amerindians alive today in the
South of Brazil, especially the Kaingang groups," he said.
According to Strauss, DNA extraction from fossils is technically
very challenging, especially if the material was found at a site with a
tropical climate. For almost two decades extreme fragmentation and
significant contamination prevented different research groups from
successfully extracting genetic material from the bones found at Lagoa
Santa.
This has now been done thanks to methodological advances developed
by the Max Planck Institute. As Strauss enthusiastically explained, much
more remains to be discovered.
"Construction of Brazil's first archaeogenetic laboratory is
scheduled to begin in 2019, thanks to a partnership between the
University of São Paulo's Museum of Archeology and Ethnology (MAE) and
its Bioscience Institute (IB) with funding from FAPESP. When it's ready,
it will give a new thrust to research on the peopling of South America
and Brazil," Strauss said.
"To some extent, this study not only changes what we know about how
the region was peopled but also changes considerably how we study human
skeletal remains," Figuti said.
Human remains were first found in Lagoa Santa in 1844, when Danish
naturalist Peter Wilhelm Lund (1801-1880) discovered some 30 skeletons
deep in a flooded cave. Almost all these fossils are now at the Natural
History Museum of Denmark in Copenhagen. A single skull has stayed in
Brazil. It was donated by Lund to the Brazilian History and Geography
Institute in Rio de Janeiro. Colonization by leaps and bounds
On the same day as the Cell article was published (November 8, 2018), a paper in the journal Science also reported new findings on fossil DNA from the first migrants to the Americas. André Strauss is one of the authors.
Among the 15 ancient skeletons from which genetic material was
taken, five belong to the Lund Collection in Copenhagen. They date from
between 10,400 and 9,800 years ago. They are the oldest in the sample,
alongside an individual from Nevada estimated to be 10,700 years old.
The sample comprised fossilized human remains from Alaska, Canada,
Brazil, Chile, and Argentina. The results of its molecular analysis
suggested the peopling of the Americas by the first human groups out of
Alaska did not come about merely through gradual occupation of territory
concomitantly with population growth.
According to the researchers responsible for the study, the
molecular data suggests that the first humans to invade Alaska or
neighboring Yukon, split into two groups. This happened between 17,500
and 14,600 years ago. One group colonized North and Central America, the
other South America.
The peopling of the Americas ensued by leaps and bounds, as small
bands of hunter-gatherers traveled far and wide to settle in new areas
until they reached Tierra del Fuego in a movement lasting one or at most
two millennia.
Among the 15 individuals whose DNA was analyzed, three of the Lagoa
Santa five were found to have some genetic material from Australasia, as
suggested by the theory proposed by Neves for the occupation of South
America. The researchers are unable to explain the origin of this
Australasian DNA or how it ended up in only a few of the Lagoa Santa
people.
"The fact that the genomic signature of Australasia has been present
for 10,400 years in Brazil but is absent in all the genomes tested to
date, which are as old or older, and found farther north, is a challenge
considering its presence in Lagoa Santa," they said.
Other fossils collected during the twentieth century include the
Luzia skull, found in the 1970s. Almost 100 skulls excavated by Neves
and Strauss in the past 15 years are now held at USP. A similar number
of fossils are held at the Pontifical Catholic University of Minas
Gerais (PUC-MG).
But the vast majority of these osteological and archeological
treasures, belonging to perhaps more than 100 individuals, were
deposited at the National Museum in Rio de Janeiro and were presumably
destroyed in the fire that raged through this historic building on
September 2, 2018.
The Luzia skull was on display at the National Museum alongside
Neave's facial reconstruction. Scientists feared it had been lost to the
fire but fortunately it was one of the first objects to be recovered
from the ruins. It had broken up but survived. The fire destroyed the
original facial reconstruction (of which there are several copies).
IMAGE: This visual abstract depicts the findings of Posth et al.,
who conducted a large-scale analysis of ancient genomes from Central
and South America yields insights into the peopling of the...
view more
Credit: Posth et al./Cell
An international research team has used genome-wide ancient DNA data
to revise Central and South American history. Their analysis of DNA
from 49 individuals spanning about 10,000 years in Belize, Brazil, the
Central Andes, and southern South America has concluded that the
majority of Central and South American ancestry arrived from at least
three different streams of people entering from North America, all
arising from one ancestral lineage of migrants who crossed the Bering
Strait some time before 15,000 years ago.
The evidence, presented November 8 in the journal Cell,
shows that within this one ancestral lineage, there were two previously
undocumented streams of gene flow from North to South America, one of
which was later displaced in a major population replacement that began
at least 9,000 years ago.
"Our work multiplied the number of ancient genomes available from
these areas by about 20, giving us a much more comprehensive picture of
indigenous history in the Americas," says co-senior author David Reich, a
geneticist at Harvard Medical School and the Howard Hughes Medical
Institute. "This broader dataset reveals a common origin of North,
Central, and South Americans as well as two previously unknown genetic
exchanges between North and South America."
"Nearly all Central and South Americans arose from a star-like
radiation of the first lineage into at least three branches," says
co-lead author Cosimo Posth, an archaeogeneticist from the Max Planck
Institute for the Science of Human History. "That means that nearly all
the ancestry of Central and South Americans came from the same source
population, albeit one that had already diversified prior to its spread
into South America. With DNA evidence largely based on present-day
people, those multiple gene flow events are undetectable, highlighting
the power of ancient DNA data."
The genome analysis also yielded new insights on the Clovis
culture-related people, who were mainly distributed across North America
from about 13,000 years ago. Archaeological evidence from Clovis sites
shows that the spread of Clovis artefacts did not expand throughout
South America. But when the researchers used genome-sequencing
technology to generate and compare genomes from a previously published
~13,000-year-old Clovis-related genome in Montana to the earliest
genomes analyzed from South and Central America dating to between ~9,000
and ~11,000 years ago, they noticed significant shared ancestry. That
suggested that the people who spread the Clovis culture also left a
major impact much father south through people producing
non-Clovis-specific stone tools.
"We weren't expecting to find a relation to people associated with
the Clovis culture in South America," says co-first author Nathan
Nakatsuka, a PhD student in Reich's lab at Harvard. "But it seems the
expansion of the Clovis-associated lineage extended to parts of Central
and South America."
The paper concludes that this Clovis-related lineage contributed
substantially to a group of 9,000-10,000-year-old individuals from Lagoa
Santa in Brazil, inconsistent with the hypothesis that the people from
this site derived from a separate migration from Asia. The authors also
detected the Clovis-related genetic affinity in an even older, almost
~11,000-year-old individual from Chile and a slightly younger, more than
~9,000-year-old individual from Belize.
Beginning around ~9,000 years ago with ancient samples in Peru,
however, the authors detected an almost complete disappearance of the
Clovis culture-associated ancestry in Central and South America,
documenting a remarkable population replacement. The large-scale
population replacement is a process that was not widely expected by
archaeologists," says Reich. "This is an exciting example of how ancient
DNA studies can reveal events in the past that were not confirmed and
thus can stimulate new work in archaeology."
The researchers also showed that after this major population
turnover, there was striking continuity compared to other parts of the
world like Eurasia and Africa. "There is remarkable continuity between
earlier and later skeletons with South Americans today," says Posth.
"For example, modern-day Quechua and Aymara from the Central Andes can
trace their ancestry back to the ancient people of the Cuncaicha site
from 9,000 years ago onwards. This is a longer-standing continuity than
you see in other continents."
The researchers recognize that there is much more work to do to fully flesh out the history of the Americas.
"We're very enthusiastic about the prospects for a much richer
understanding of American population history, but this is still a vast
region full of geographic and chronological holes," says Reich. "We'd
like to collect more genetic material from earlier and later sites and
from more countries, such as Colombia, Venezuela, and other parts of
Brazil. We also want to examine the evolution of genetic traits over
time."
Adaptations to the harsh environment spare Andean highlanders from complete devastation due to European contact
University of Chicago Medical Center
IMAGE: This is the location of ancient samples near Lake Titicaca, elevation 3812 meters, in what is now Peru and Bolivia.
view more
Credit: Authors of the study
A multi-center study of the genetic remains of people who settled
thousands of years ago in the Andes Mountains of South America reveals a
complex picture of human adaptation from early settlement, to a split
about 9,000 years ago between high and lowland populations, to the
devastating exposure to European disease in the 16th-century colonial
period.
Led by Anna Di Rienzo, PhD, and John Lindo, PhD, JD, from the
University of Chicago; Mark Aldenderfer, PhD, from the University of
California, Merced; and Ricardo Verdugo from the University of Chile,
the researchers used newly available samples of DNA from seven whole
genomes to study how ancient Andean people--including groups that
clustered around Lake Titicaca in Peru and Bolivia, 12,000 feet above
sea level--adapted to their environment over the centuries.
In the journal Science Advances, they compared their seven
historical genomes to 64 modern-day genomes from a current highland
Andean population, the agropastoral Aymara of Bolivia, and the lowland
hunter-gatherer Huilliche-Pehuenche in coastal Chile.
The goals were (1) to date the initial migration to the Andean
highlands, (2) to identify the genetic adaptations to the high-altitude
environment that allowed that settlement, (3) to estimate the impact of
the European contact starting in the 1530s that caused the near
annihilation of many lowland communities of South America.
"We have very ancient samples from the high Andes," said Di Rienzo.
"Those early settlers have the closest affinity to the people who now
live in that area. This is a harsh, cold, resource-poor environment,
with low oxygen levels, but people there adapted to that habitat and the
agrarian lifestyle."
The study, "The Genetic prehistory of the Andean highlands 7,000
years BP through European contact," uncovered several unexpected
features.
The researchers found that highland Andeans experienced much smaller
than expected population declines following contact with European
explorers who first came to South America in the 1530s. In the lowlands,
demographic modeling and historical records infer that up to 90 percent
of residents may have been wiped-out after the arrival of Europeans.
But the people living in the upper Andes had only a 27-percent
population reduction.
Even though the highlanders lived in altitudes above 8,000 feet,
which meant reduced oxygen, frequent frigid temperatures and intense
ultra-violet radiation, they did not develop the responses to hypoxia
seen in natives of other high-altitude settings, such as Tibet.
The Andeans may have adapted to high altitude hypoxia "in a
different way, via cardiovascular modifications," the researchers
suggest. They found evidence of alterations in a gene called DST, which
is associated with the formation of cardiac muscle. Andean highlanders
tend to have enlarged right ventricles. This may have improved oxygen
intake, enhancing blood flow to the lungs.
But the strongest adaptation signal the researchers found was in a
gene called MGAM (maltase-glucoamylase) an intestinal enzyme. It plays
an important role in the digestion of starchy foods such as potatoes--a
food native to the Andes. A recent study suggests that the potato may
have been domesticated in the region at least 5,000 years ago. Positive
selection on the MGAM gene, the authors note, "may represent an adaptive
response to greater reliance upon starchy domesticates."
The early presence of this variant in Andean peoples suggests "a
significant shift in diet from one that was likely more meat based to
one more plant based," said UC Merced's Aldenderfer, an anthropologist.
"The timing of the appearance of the variant is quite consistent with
what we know of the paleo-ethno-botanical record in the highlands."
Although Andean settlers consumed a high-starch diet after they
started to farm, their genomes did not develop additional copies of the
starch related amylase gene, commonly seen in European farming
populations.
A comparison of the ancient genomes with their living descendants
also revealed selection for immune-related genes soon after the arrival
of Europeans, suggesting that Andeans who survived may have had an
advantage with regard to the newly introduced European pathogens.
"Contact with Europeans had a devastating impact on South American
populations, such as the introduction of disease, war, and social
disruption," explained Lindo. "By focusing on the period before that, we
were able to distinguish environmental adaptations from adaptations
that stemmed from historical events."
"In our paper," said Aldenderfer, "there was none of this
prioritization of genes at the expense of archaeological data. We worked
back and forth, genetics and archeology, to create a narrative
consistent with all of the data at hand."
