The encounter between Neanderthals and Sapiens as told by their genomes

analysed the distribution of the portion of DNA inherited from Neanderthals in the genomes of humans (Homo sapiens) over the last 40,000 years.
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Image Credit: © Claudio Quilodrán

About 40,000 years ago, Neanderthals, who had lived for hundreds of thousands of years in the western part of the Eurasian continent, gave way to Homo sapiens, who had arrived from Africa. This replacement was not sudden, and the two species coexisted for a few millennia, resulting in the integration of Neanderthal DNA into the genome of Sapiens. Researchers at the University of Geneva (UNIGE) have analyzed the distribution of the portion of DNA inherited from Neanderthals in the genomes of humans (Homo sapiens) over the last 40,000 years. These statistical analyses revealed subtle variations in time and geographical space. This work, published in the journal Science Advances, helps us to understand the common history of these two species. 

Thanks to genome sequencing and comparative analysis, it is established that Neanderthals and Sapiens interbred and that these encounters were sometimes fruitful, leading to the presence of about 2% of DNA of Neanderthal origin in present-day Eurasians. However, this percentage varies slightly between regions of Eurasia, since DNA from Neanderthals is somewhat more abundant in the genomes of Asian populations than in those of European populations. 

Climate and human land use both play roles in Pacific island wildfires past and present

SMU fire scientist Christopher Roos
Photo Credit: Courtesy of  Southern Methodist University

It’s long been understood that human settlement contributes to conditions that make Pacific Islands more susceptible to wildfires, such as the devastating Aug. 8 event that destroyed the Maui community of Lahaina. But a new study from SMU fire scientist Christopher Roos published in the journal Nature Ecology & Evolution shows that climate is an undervalued part of the equation.

Roos, SMU environmental archaeologist and professor of anthropology, traveled with his team to the Sigatoka River valley in southwestern Fiji in 2013, where they collected charcoal and stable carbon isotopes from deep soil cores to understand historic patterns of fire activity in the area. Different plants have distinct carbon isotopic signatures, which can provide information about past plant communities.

The team found fires and fire-created grassy areas that predate human settlement by millennia and actively corresponded to droughts likely driven by a regularly occurring weather pattern known as El Niño. El Niño events can alter precipitation patterns worldwide, making environmental conditions more favorable for wildfires. The National Oceanic and Atmospheric Administration issued an El Niño advisory in June, announcing the latest arrival of the climate event that continues to influence weather worldwide.

New study shows signs of early creation of modern human identities

SapienCE researchers have publiched a new study which provides vital information about how and when we may have started developing modern human identities. Image showing excavation at Blombos Cave, South Africa.
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Photo Credit: UiB, SapienCE

The study, which is newly published in the Journal of Human Evolution, confirms previous scant evidence, and supports a multistep evolutionary scenario for the culturalization of the human body.

Eye-catching shells made into ornaments

The new study is conducted by Francesco d'Errico, Karen Loise van Niekerk, Lila Geis and Christopher Stuart Henshilwood. The significant findings provide vital information about how and when we may have started developing modern human identities.

“The discovery of eye-catching unmodified shells with natural holes from 100 to 73 ka confirms previous scant evidence that marine shells were collected, taken to the site and, in some cases, perhaps worn as personal ornaments before a stage in which shells belonging to selected species were systematically, and intentionally perforated with suitable techniques to create composite beadworks”, van Niekerk says.

Similar shells have been found in North Africa, other sites in South Africa and the Mediterranean Levant, which means that the argument is supported by evidence from other sites, not just Blombos Cave.

Hunting anything that flies

Pillar from Göbekli Tepe depicting a vulture with its wings spread. 
Photo Credit: © Nadja Pöllath / SNSB-SPM

Birds were an important source of food for hunter-gatherer communities in Upper Mesopotamia at the beginning of the Neolithic period. Besides mammals, ranging from aurochs to hares, or fish, foragers also pursued an impressively large spectrum of bird species in Southeast Anatolia 11,000 years ago. They were hunted mainly, but not exclusively, in autumn and winter – at the time of year, when many bird species form larger flocks and migratory birds cross the area. The species lists are therefore very extensive: At the famous Early Neolithic settlement and the world's oldest temple complex of Göbekli Tepe, for example, c. 18 km northeast of present-day Şanlıurfa (SE Anatolia, Turkey), the researchers identified the remains of at least 84 bird species. Dr. Nadja Pöllath, curator at the Bavarian State Collection for Palaeoanatomy (Staatssammlung für Paläoanatomie München SNSB-SPM) and Prof. Joris Peters, chair of the Institute for Palaeoanatomy, Domestication Research and History of Veterinary Medicine at LMU München and director of the state collection, identified the Neolithic bird bones with the aid of the reference skeletons of the state collection.

The researchers were surprised by the large number of small passerine birds identified at Göbekli Tepe, comprising mainly starlings and buntings. In principle, the Early Neolithic inhabitants of Göbekli Tepe hunted birds in all habitats – mainly in the open grassland and wooded steppe in their direct surroundings, but also in the wetlands and gallery forest somewhat further away.

New insights into the origin of food sharing among humans

Chimpanzees Gremlin and son Grendel, begging for food, at Gombe National Park, Tanzania.
Photo Credit: Courtesy of University of Minnesota

As humans evolved to hunt, gather and share food, cooperation provided a key to our success as a species. While chimpanzees and other primates sometimes share food, humans stand out. As hunter-gatherers — the subsistence strategy that all humans followed until the invention of agriculture — our survival depended on daily sharing of food between unrelated adult males and females. 

While hunter-gatherers today depend heavily on hunting and cooking, long before these activities became important for our ancestors, species such as Australopithecus extracted foods such as roots, tubers and nuts. Since hunter-gatherers and nonhuman primates tend to share foods that are large, valuable and divisible, these nutrient-dense foods are likely candidates for sharing, and may have been susceptible to theft by hungry group members. 

In new research published in the Proceedings of the National Academy of Sciences (PNAS), a team led by College of Biological Sciences Professor Michael Wilson developed a conceptual and mathematical model of the evolution of food production and sharing in early human ancestors. The interdisciplinary team included an economist, a theoretical biologist, an anthropologist and a primatologist. 

Romantic Love in Humans May Have Evolved From Same-Sex Friendship

Two adolescent male chimpanzees, Barron, 15, and PeeWee, 9, grooming.
Photo Credit: Aaron Sandel.

Romantic heterosexual relationships in humans may have evolved from same-sex pairings in a common ancestor of humans and chimpanzees, according to a novel hypothesis by a researcher at The University of Texas at Austin.

The prevailing explanation of heterosexual pair bonding and romantic love in humans is that it evolved from the mother-infant bond present in many mammals. In a paper published in the journal Evolutionary Anthropology, anthropology professor Aaron Sandel cites primate research — including his own decadelong studies of chimpanzees in Kibale National Park, Uganda — to propose instead that this behavior evolved in humans from same-sex pair bonding already present in a common ancestor of humans and chimpanzees.

A pair bond is a cooperative relationship between nonrelated adults that remains stable over time and includes an emotional connection, rather than being merely transactional. Chimpanzees, humans’ closest relative, do not pair bond with their mates, but adult males of the species form same-sex bonds lasting as long as 13 years.

New Model for Human Evolution Suggests Homo Sapiens Arose from Multiple Closely Related Populations

View of the village of Kuboes, on the border of South Africa and Namibia. DNA samples were collected from Nama individuals who have historically lived in the region.
Photo Credit: Brenna Henn/UC Davis

In testing the genetic material of current populations in Africa and comparing against existing fossil evidence of early Homo sapiens populations there, researchers have uncovered a new model of human evolution — overturning previous beliefs that a single African population gave rise to all humans. The new research was published today, May 17, in the journal Nature.

Although it is widely understood that Homo sapiens originated in Africa, uncertainty surrounds how branches of human evolution diverged and how people migrated across the continent, said Brenna Henn, professor of anthropology and the Genome Center at UC Davis, corresponding author of the research.

“This uncertainty is due to limited fossil and ancient genomic data, and to the fact that the fossil record does not always align with expectations from models built using modern DNA,” she said. “This new research changes the origin of species.”

Research co-led by Henn and Simon Gravel of McGill University tested a range of competing models of evolution and migration across Africa proposed in the paleoanthropological and genetics literature, incorporating population genome data from southern, eastern and western Africa.

Apes may have evolved upright stature for leaves, not fruit, in open woodland habitats

Artistic rendering of the open woodland habitat reconstruction at Moroto II with Morotopithecus bishopi vertically climbing with infant on back and juvenile below. Active volcano (Mount Moroto) is in background. Fossil relative of an elephant (Prodeinotherium) is foraging in center back.
Illustration Credit: Corbin Rainbolt

Anthropologists have long thought that our ape ancestors evolved an upright torso in order to pick fruit in forests, but new research from the University of Michigan suggests a life in open woodlands and a diet that included leaves drove apes’ upright stature.

The findings shed light on ape origins and push back the origin of grassy woodlands from between 7 million and 10 million years ago to 21 million years ago in equatorial Africa, during the Early Miocene.

Fruit grows on the spindly peripheries of trees. To reach it, large apes need to distribute their weight on branches stemming from the trunk, then reach out with their hands toward their prize. This is much easier if an ape is upright because it can more easily grab onto different branches with its hands and feet. If its back is horizontal, then its hands and feet are generally underneath the body, making it much harder to move outward to the smaller branches of a tree—especially if the ape is large bodied.

Ancient DNA reveals entwined African and Asian ancestry along the Swahili coast of eastern Africa

Rice researchers Mary Prendergast and Jeffrey Fleisher.
Photo Credit: Brandon Martin.

A new genetic study of medieval people who lived along the Indian Ocean coast of eastern Africa — an area often called the “Swahili coast” for its language and culture — revealed that they had both African and Persian ancestry.

The results suggest that maritime trade connections long recognized by archaeologists based on imported goods and architectural influences fostered relationships between Asian merchants and African traders and their families.

“Entwined African and Asian genetic roots of medieval peoples of the Swahili coast” was published today in Nature. It examines genetic ancestry and cultural influences in eastern Africa by using DNA from the skeletal remains of 80 individuals who were buried in six medieval and early modern coastal towns in Kenya and Tanzania dating to the years 1250-1800 and an inland town in Kenya dating to after 1650.

Analysis of the genetic data enabled scientists to estimate that people of African and Persian ancestry began to have children together around the year 1000, centuries before the burials themselves.

23,000-year-old human genome from southern Spain decoded

Human tooth recovered Cueva de Malalmuerzo
Photo Credit: Pedro Cantalejo

A new study reports on genomic data from a 23,000-year-old individual who lived in what was probably the warmest place in Europe at the peak of the last Ice Age. The oldest human genome recovered from the southern tip of Spain adds an important piece of the puzzle to the genetic history of Europe.

An international team of researchers has analyzed ancient human DNA from several archaeological sites in Andalucía in southern Spain. The study, published in Nature Ecology and Evolution, reports on the oldest genome to date from Cueva del Malalmuerzo in southern Spain, as well as the 7,000 to 5,000-year-old genomes of early farmers from other well-known sites, such as Cueva de Ardales. The researchers describe their findings in the article ‘A 23,000-year-old southern-Iberian individual links human groups that lived in Western Europe before and after the Last Glacial Maximum’ in the Journal Nature Ecology and Evolution.

The Iberian Peninsula plays an important role in the reconstruction of human population history. As a geographic cul-de-sac in the southwest of Europe, it is on one hand considered a refuge during the last Ice Age with its drastic temperature fluctuations. On the other hand, it may have been one of the starting points for the recolonization of Europe after the glacial maximum. Indeed, previous studies had reported on the genomic profiles of 13,000 to 8,000-year-old hunter-gatherers from the Iberian Peninsula and provided evidence for the survival and continuation of a much older Paleolithic lineage that has been replaced in other parts of Europe and is no longer detectable. 

New Study Shows Archery Appeared in Europe Thousands of Years Earlier than Previously Thought

Laure Metz making experimental bow and arrow shots with arrows armed with Neronian light points.
 Photo Credit: Ludovic Slimak

The use of bow-and-arrow technology gave humans an edge over Neanderthal neighbors in hunting game

A new study published in Science Advances contextualizes the traditions and technological knowledge of early, pioneering Homo sapiens. The study demonstrates the mastery of archery by modern populations and extends the evidence of archery in Europe back by about 40,000 years.

The researchers analyzed lithic artifacts from a cave in Mediterranean France called Grotte Mandrin, which reveals the oldest occupation of modern humans on the European continent. The study focuses on a very rich level, attributed to the Neronian culture, and testifies to Homo sapiens occupations dating back 54,000 years, interposed between numerous Neanderthal occupations in the cave before and after the modern humans. That’s roughly 10,000 years earlier than what had been previously believed to be the earliest occupation of modern humans in Europe.

The research was directed by Laure Metz, an associated researcher at UMR 7269 (UMR LAMPEA, CNRS, Aix-Marseille University), and Ludovic Slimak, CNRS researcher (UMR 5608 TRACES, Toulouse Jean Jaurès University). Metz is a UConn-affiliated researcher and former post-doctoral researcher in the UConn Department of Anthropology Deep History Lab led by Professor Christian Tryon.

Early humans: Annual cycles in tooth enamel provide insights into life histories

Jülide Kubat and Wolfgang Müller load the LA-ICPMS with a thin section of tooth for analysis.
Photo Credit: Jülide Kubat

An interdisciplinary team of scientists, led by Goethe University Frankfurt and the Senckenberg Research Institute and Natural History Museum Frankfurt, has discovered – by analyzing their teeth – what our ancestors of the species Homo erectus ate hundreds of thousands of years ago on the island of Java in Southeast Asia: over the course of a year, these early humans switched from a plant-based diet to a mixed one, but were far less dependent on seasonal food supply than, for example, orangutans, which also inhabited the island.

If you take a magnifying glass and a torch and look at your teeth very carefully in the mirror, in places you can spot a pattern of fine, parallel lines running across your teeth. These correspond to the striae of Retzius that mark the growth of our tooth enamel. Enamel starts forming in the womb and continues to mineralize until adolescence, when the last milk teeth fall out and are replaced by permanent ones. Like in all land-dwelling vertebrates, tooth enamel mineralizes gradually in microscopically thin layers in humans too, represented by the striae of Retzius. The speed with which a human develops can be read from these Retzius lines. Physiological changes, such as birth, weaning or illness, for example, leave distinctive traces. The striae of Retzius also form the chronological framework for the chemical composition of tooth enamel, which in turn reflects changes in the diet of that individual.

New study suggests Mayas utilized market-based economics

Obsidian collections from the site of Q'umarkaj and the surrounding region.
Photo Credit: Rachel Horowitz

More than 500 years ago in the midwestern Guatemalan highlands, Maya people bought and sold goods with far less oversight from their rulers than many archeologists previously thought.

That’s according to a new study in Latin American Antiquity that shows the ruling K’iche’ elite took a hands-off approach when it came to managing the procurement and trade of obsidian by people outside their region of central control.

In these areas, access to nearby sources of obsidian, a glasslike rock used to make tools and weapons, was managed by local people through independent and diverse acquisition networks. Over time, the availability of obsidian resources and the prevalence of craftsmen to shape it resulted in a system that is in many ways suggestive of contemporary market-based economies.

“Scholars have generally assumed that the obsidian trade was managed by Maya rulers, but our research shows that this wasn’t the case at least in this area,” said Rachel Horowitz, lead author of the study and an assistant professor of anthropology at Washington State University. “People seem to have had a good deal of economic freedom including being able to go to places similar to the supermarkets we have today to buy and sell goods from craftsmen.”

Early humans may have first walked upright in the trees

Photo Credit: Alexa

Human bipedalism – walking upright on two legs – may have evolved in trees, and not on the ground as previously thought, according to a new study involving UCL researchers.

In the study, published in the journal Science Advances, researchers from UCL, the University of Kent, and Duke University, USA, explored the behaviors of wild chimpanzees - our closest living relative - living in the Issa Valley of western Tanzania, within the region of the East African Rift Valley.

Known as ‘savanna-mosaic’ – a mix of dry open land with few trees and patches of dense forest - the chimpanzees’ habitat is very similar to that of our earliest human ancestors and was chosen to enable the scientists to explore whether the openness of this type of landscape could have encouraged bipedalism in hominins.

The study is the first of its kind to explore if savanna-mosaic habitats would account for increased time spent on the ground by the Issa chimpanzees, and compares their behavior to other studies on their solely forest-dwelling cousins in other parts of Africa.

Overall, the study found that the Issa chimpanzees spent as much time in the trees as other chimpanzees living in dense forests, despite their more open habitat, and were not more terrestrial (land-based) as expected.

Jawbone may represent earliest presence of humans in Europe

For over a century, one of the earliest human fossils ever discovered in Spain has been long considered a Neandertal. However, new analysis from an international research team, including scientists at Binghamton University, State University of New York, dismantles this century-long interpretation, demonstrating that this fossil is not a Neandertal; rather, it may actually represent the earliest presence of Homo sapiens ever documented in Europe.

In 1887, a fossil mandible was discovered during quarrying activities in the town of Banyoles, Spain, and has been studied by different researchers over the past century. The Banyoles fossil likely dates to between approximately 45,000-65,000 years ago, at a time when Europe was occupied by Neandertals, and most researchers have generally linked it to this species.

“The mandible has been studied throughout the past century and was long considered to be a Neandertal based on its age and location, and the fact that it lacks one of the diagnostic features of Homo sapiens: a chin,” said Binghamton University graduate student Brian Keeling.

The new study relied on virtual techniques, including CT scanning of the original fossil. This was used to virtually reconstruct missing parts of the fossil, and then to generate a 3D model to be analyzed on the computer.

Genes and Languages

Schematic illustration of possible scenarios of matches and mismatches in the transmission of genes and languages. Genetic (demographic) history is represented by a broad branching tree. Linguistic history is represented by colored lines, differentiating five language families (a-e).
Illustration Credit Barbieri et al., PNAS

More than 7,000 languages are spoken in the world. This linguistic diversity is passed on from one generation to the next, similarly to biological traits. But have language and genes evolved in parallel over the past few thousand years, as Charles Darwin originally thought? An interdisciplinary team at the University of Zurich together with the Max Planck Institute for Evolutionary Anthropology in Leipzig (Germany) has now examined this question at a global level. The researchers put together a global database linking linguistic and genetic data entitled GeLaTo (Genes and Languages Together), which contains genetic information from some 4,000 individuals speaking 295 languages and representing 397 genetic populations.

One in five gene-language links point to language shifts

In their study, the researchers examined the extent to which the linguistic and genetic histories of populations coincided. People who speak related languages tend to also be genetically related, but this isn’t always the case. “We focused on cases where the biological and linguistic patterns differed and investigated how often and where these mismatches occur,” says Chiara Barbieri, UZH geneticist who led the study and initiated it together with colleagues when she was a postdoc at the Max-Planck-Institute.

Study provides first snapshot of global experiences with water insecurity

A new study by Northwestern anthropologists reveals the life-altering problems with water that have long gone hidden. 
Photo Credit: Charles Nambasi

Countries in Latin America, Asia and Africa have experienced severe droughts and unprecedented floods in the last year. New research from Northwestern University is the first to provide a more nuanced and global view of the experience of water insecurity.

In a new study published in The Lancet Planetary Health, scientists estimate that 436 million of the 3 billion adults represented by the survey sample were water insecure in 2021. The researchers also were able to pinpoint which groups experience the highest rates of water insecurity.

The study, led by Northwestern anthropologist Sera Young, uses data drawn from a nationally representative sample of nearly half the world’s population and a scale designed to measure water insecurity more holistically.

Young is an associate professor of anthropology and global health studies at Weinberg College of Arts and Sciences and a faculty fellow at the Institute for Policy Research (IPR) at Northwestern. Study collaborators include Hilary Bethancourt, assistant research professor of anthropology and IPR at Northwestern.

“These data bring a human face to the water sector, thereby revealing life-altering problems with water that have long gone hidden,” Young said.

How Prehistoric Humans Simplified the World’s Food Webs

Illustration depicting all mammal species that would inhabit Southern California today if not for human-linked extinction. Extinct species appear in black and white.
Credit: Oscar Sanisidro/University of Alcalá

Research conducted with the help of a University at Albany anthropologist has revealed the cascading effects that humans have had on mammal declines and their food webs over the last 130,000 years, a new study in the journal Science shows.

The study, which was carried out by researchers in the United States, United Kingdom, Denmark and Spain, set out to determine the magnitude of food web loss among mammals since the Late Pleistocene, following the arrival and expansion of human populations around the world.

“We’ve known for a long time that as humans spread out of Africa, everywhere they went, waves of animal extinctions followed their arrival,” said John Rowan, an assistant professor of anthropology at UAlbany who co-authored the study. “When humans got to North America, there were saber-toothed cats, dire wolves, mammoths, mastodons and giant bears. But all these animals start to disappear soon after our species show up.”

While scientists were aware of the human link to mammal extinctions, little was understood regarding how those losses reverberated throughout food webs, which characterize how species interact with one another in an ecosystem. Extinction alone can impact the links in a food web, but so can reductions and shifts in geographic range due to human impacts, such as habitat destruction.

Study of Ancient Skulls Sheds Light on Human Interbreeding With Neandertals

Homo neanderthalensis adult male. Reconstruction based on Shanidar 1 by John Gurche for the Human Origins Program, NMNH.
Photo Credit: Chip Clark.

Research has established that there are traces of Neandertal DNA in the genome of modern humans. Now an exploratory study that assessed the facial structure of prehistoric skulls is offering new insights, and supports the hypothesis that much of this interbreeding took place in the Near East – the region ranging from North Africa to Iraq.

“Ancient DNA caused a revolution in how we think about human evolution,” says Steven Churchill, co-author of the study and a professor of evolutionary anthropology at Duke University. “We often think of evolution as branches on a tree, and researchers have spent a lot of time trying to trace back the path that led to us, Homo sapiens. But we’re now beginning to understand that it isn’t a tree – it’s more like a series of streams that converge and diverge at multiple points.”

“Our work here gives us a deeper understanding of where those streams came together,” says Ann Ross, corresponding author of the study and a professor of biological sciences at North Carolina State University.

“The picture is really complicated,” Churchill says. “We know there was interbreeding. Modern Asian populations seem to have more Neandertal DNA than modern European populations, which is weird – because Neandertals lived in what is now Europe. That has suggested that Neandertals interbred with what are now modern humans as our prehistoric ancestors left Africa, but before spreading to Asia. Our goal with this study was to see what additional light we could shed on this by assessing the facial structure of prehistoric humans and Neandertals.”

The brains of Neanderthals developed differently from those of modern humans

Fewer chromosome segregation errors in modern human than Neanderthal neural stem cells. Left side: microscopy image of the chromosomes (in cyan) of a modern human neural stem cell of the neocortex during cell division. Right side: same type of image, but of a cell where three amino acids in the two proteins KIF18a and KNL1, involved in chromosome separation, have been changed from the modern human to the Neanderthal variants. These “neanderthalized” cells show twice as many chromosomes separation errors (red arrow). 
Credit: Felipe Mora-Bermúdez / MPI-CBG

Neanderthals are the closest relatives to modern humans. The neocortex, the largest part of the outer layer of the brain, is unique to mammals and crucial for many cognitive capacities. Researchers from the Max Planck Institute of Molecular Cell Biology and Genetics in Dresden and the Max Planck Institute for Evolutionary Anthropology in Leipzig have now discovered that neural stem cells – the cells from which neurons in the developing neocortex derive – spend more time preparing their chromosomes for division in modern humans than in Neanderthals. This results in fewer errors when chromosomes are distributed to the daughter cells in modern humans than in Neanderthals or chimpanzees, and could have consequences for how the brain develops and functions.

After the ancestors of modern humans split from those of Neanderthals and Denisovans, their Asian relatives, about one hundred amino acids, the building blocks of proteins in cells and tissues, changed in modern humans and spread to almost all modern humans. The biological significance of these changes is largely unknown. However, six of those amino acid changes occurred in three proteins that play key roles in the distribution of chromosomes, the carriers of genetic information, to the two daughter cells during cell division.