Tag Archives: Neanderthal

Humans and Neanderthals diverged at least 800,000 years ago, new teeth study shows

The origin of humans and our closest cousins, the Neanderthals, has been hotly debated. Now, a new study suggests that the two lineages diverged much earlier than anticipated — and the key might lie in modern-looking teeth.

Hominin teeth. Image credits: Aida Gómez-Robles.

The Atapuerca Mountains in north-eastern Spain might not look like much. They feature gentle slopes and a rather dry landscape, interrupted from place to place by forests and the occasional river. But these mountains hold a karstic environment that is key to understanding how humans came to be, and what life was for our early ancestors.

The most important site is a cave called Sima de los Huesos (Pit of Bones). Anthropologists have recovered over 5,500 human remains which are at least 350,000 years old. The remains belong to 28 individuals of Homo heidelbergensis, an archaic hominin that lived from approximately 700,000 years to 300,000 years ago. Researchers also found fossils of cave bears and some remarkable tools and structures developed by these ancient humans.

In 2016, nuclear DNA analysis showed that remains from some individuals belong to Neanderthals, also suggesting that the divergence between Neanderthals and Denisovans (more enigmatic cousins of ours) happened at least 430,000 years ago. Now, Aida Gómez-Robles, an anthropologist at University College London, believes the cave might also have some clues as to when Neanderthals split from humans.

Gómez-Robles studies what makes humans distinct from other primate species, despite our genetic similarities. She also looks at teeth, in particular, using dental variations to assess the evolutionary relationships of fossil hominins. She believes that the Neanderthal teeth found in the cave look more modern than they should, which offers two possibilities: either the teeth evolved unusually quickly (and there’s no reason to believe that that might be the case) or, as she believes, the teeth had more time to evolve. If the latter is true, then this would mean that Neanderthals split up from our own lineage earlier than expected: some 800,000 years ago.

“There are different factors that could potentially explain these results, including strong selection to change the teeth of these hominins or their isolation from other Neanderthals found in mainland Europe. However, the simplest explanation is that the divergence between Neanderthals and modern humans was older than 800,000 years. This would make the evolutionary rates of the early Neanderthals from Sima de los Huesos roughly comparable to those found in other species.”

Previously, DNA analyses have generally indicated that the lineages diverged around 300,000 to 500,000 years ago. This was very important for anthropological context since researchers took it as a temporal anchor for interpreting other findings. However, anatomical evidence (such as the teeth in the Pit of Bones) seems to contradict this timeline. All the evidence we have seems to suggest that dental shape has evolved at very similar rates across all hominin species, so there’s not much reason to believe Neanderthals would be an exception. It’s a strong argument and a plausible scenario.

“The Sima people’s teeth are very different from those that we would expect to find in their last common ancestral species with modern humans, suggesting that they evolved separately over a long period of time to develop such stark differences,” Gómez-Robles adds.

However, not everyone is convinced. Paleoanthropologist Rick Potts, director of the Smithsonian’s Human Origins Program says that it’s an interesting find, but there’s not enough evidence to counterbalance the previous molecular and DNA results. It’s also unclear why only teeth seem to be heavily evolved — the rest is in accordance with the 300,000-500,000 timeline.

There’s also another complication: hybridization. Neanderthals have been found to interbreed with humans and Denisovans, and during this period, with populations being separated from each other, adapting to a particular environment, and then being re-united and starting breeding again — we don’t really know what the effect of that might have on tooth evolution.

Without additional evidence, the jury is still out regarding the early evolution of these hominin species, but this new study goes to show just how complex our evolutionary history is, and how difficult it is to uncover the intricacies that led to the development of humans and our cousins.

The study was published in Science Advances.

First Denisovan fossil found outside of Siberia — our ancient “cousins” spread far and wide

When the first Denisovan fossil was found in 2010, it was hailed as a stunning discovery. Here was another species related to humans, clearly distinct from the Neanderthals and Homo sapiens. However, fossil evidence of this species had only been found in the Denisova Cave in Siberia, from which the Denisovans were named.

Now, a new fossil discovered in Tibet shows that the Denisovans weren’t nearly as localized as some thought. They spread far and wide, being capable of living at impressive altitudes.

Virtual reconstruction of the jawbone. Image credits: Jean-Jacques Hublin, MPI-EVA, Leipzig.

High Denisovans

Back in 1980, a Tibetan monk found a rather unusual fossil: a seemingly human jawbone. The monk passed it on to Lanzhou University, but the fragment was ignored until the 2010s when archaeologist Dongju Zhang and her colleagues began studying the bone. A recent study has now confirmed that the jawbone belonged to a Denisovan, a group of humanoids that lived alongside humans and Neanderthals, interbreeding with them several times across history.

Although genetic analysis has shown that the Denisovans were a unique group, remains from them have been sparse, and until now, limited only to the Denisova Cave. Of course, it’s not plausible that a humanoid group inhabited a single cave, so the hunt was on for other fossils. Jean-Jacques Hublin of the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, wondered if they could find such remains in the Tibetan plateau, and turned to the jawbone from Lanzhou University.

Denisovans split from humans about 550,00–765,000 years ago, but we still carry some of their genetic legacies. Previous studies have suggested that Denisovans were well adapted to living in cold environments and at high altitudes, but the fact that they could survive in Tibet is remarkable.

The altitude of the new Denisovan’s home is 3,280 meters ( 10,700 feet) above sea level, an altitude at which you need special adaptations to be able to survive. This also changes the anthropological history of Tibet and the Himalayas, as previous research claimed that the area was first populated by humans around 40,000 years ago. This new finding pushes that date back by 100,000 years.

The fossil was found in this type of Tibetan landscape. Image credits: Dongju Zhang, Lanzhou University.

It’s not completely surprising, however — actually, this finding might help solve one pressing riddle about the genetic history of the Tibetan people: Tibetans and other populations in the region have a gene inherited from Denisovans that helps them live at high altitudes, but how they got this gene from the Denisovans in the first place is a mystery. The fact that Denisovans developed it in the first place was just as puzzling, considering that their only remains had been found in a low-lying area.

“Frankly speaking, until today, nobody ever imagined that archaic humans could be able to dwell in such an environment,” said Jean-Jacques Hublin, a co-author and paleoanthropologist at the Max Planck Institute for Evolutionary Anthropology. “It’s a big surprise because most people thought that challenging environments like the high altitudes were colonized only by modern humans like us less than 40,000 years ago.”

No DNA

Identifying what species the jawbone came from is no easy feat. The fragment is at least 160,000 years old, and DNA tends to disintegrate much quicker than that. So instead, researchers looked at a specific set of proteins, which is much more durable than DNA. Essentially, the strings of amino acids found in some protein can be a tell-tale sign of a particular species.

“Just like DNA, the amino acids in these proteins are ordered in a particular way,” said co-author Frido Welker, a researcher at the Max Planck Institute for Evolutionary Anthropology. “And we can actually sequence these proteins, so we can read the order of those amino acids.”

Of course, DNA analysis would still be much better. This type of protein analysis is still a nascent field, with a low sample size. But for the lack of a better approach, it offers much-needed information. Researchers also hope that these patterns could help determine other bones that they discovered. Researchers working in China have found several such fossils which are still unidentified.

“In China there are a number of specimens that are not Homo erectus, that are not modern humans, and that are good candidates for being Chinese Denisovans,” Hublin said. “But this has been impossible to prove today because in these fossils there is no ancient DNA preserved.”

“I predict that most of the Chinese hominin fossil record younger than 350,000 years and older than 50,000 is made of Denisovans,” he adds.

Identifying these remains could offer some valuable puzzle pieces as to who the Denisovans were, what they looked like, and how they passed on their genes. Also, if Hublin is right, this might help settle the debate over whether our ancestors evolved solely in Africa, or whether Asia played an important role too.

The study was published in the journal Nature.

Woolly mammoths and Neanderthals shared genetic traits

Credit: Wikimedia Commons.

They say you are what you eat. This saying is particularly apt for Neanderthals, who both ate woolly mammoths and shared some genetic traits with them. That’s not to say that there was any gene transfer through the gut. Instead, the researchers believe that the two species of mammals co-evolved the same adaptations to their environment.

Both Woolly mammoths (Mammuthus primigenius) and our extinct cousins, the Neanderthals (Homo neanderthalensis), hailed from African ancestors which migrated to Europe, where they adapted to living conditions in Ice Age Europe. Woolly mammoths first appeared in the Arctic peninsula around 600,000 years ago while Neanderthals appeared in Europe around 400,000 years ago. For tens of thousands of years, the two species regularly interacted. Intriguingly, both species went extinct around the same time around 40,000 years ago when humans began rapidly expanding across the continent.

Given their shared history, researchers at Tel Aviv University wondered if there were any genetic traits that the two species also shared. The research team led by Prof. Ran Barkai from the university’s Department of Archaeology and Ancient Near Eastern Cultures reviewed three cases studies of gene variants and alleles (an alternative form of a gene). The researchers were interested in finding genetic material related to cold-climate adaptation which can be found in the genomes of both species.

The studies revealed the mutual appearance of several genes, including LEPR (involved in thermogenesis and the regulation of fat storage in the body), MC1R and SLC7A11 (related to skin and hair pigmentation), as well as genes related to keratin protein production (the type of protein that makes up your hair, skin, and nails).

“Our observations present the likelihood of resemblance between numerous molecular variants that resulted in similar cold-adapted epigenetic traits of two species, both of which evolved in Eurasia from an African ancestor,” explained Meidad Kislev, the study’s co-author. “These remarkable findings offer supporting evidence for the contention regarding the nature of convergent evolution through molecular resemblance, in which similarities in genetic variants between adapted species are present.

“We believe these types of connections can be valuable for future evolutionary research. They’re especially interesting when they involve other large-brained mammals, with long life spans, complex social behavior and their interactions in shared habitats with early humans.”

Both species are extinct today, but they still have living relatives. Neanderthals have humans and mammoths have elephants — in fact, African and Asian elephants are more closely related to the woolly mammoth than to each other. However, this situation might not last long. Seventy-five percent of elephant populations are estimated to be declining, signaling a process of extinction fueled by black market demand for ivory.

“It is now possible to try to answer a question no one has asked before: Are there genetic similarities between evolutionary adaptation paths in Neanderthals and mammoths?” Prof. Barkai says. “The answer seems to be yes. This idea alone opens endless avenues for new research in evolution, archaeology and other disciplines.

“At a time when proboscideans are under threat of disappearance from the world due to the ugly human greed for ivory, highlighting our shared history and similarities with elephants and mammoths might be a point worth taking into consideration.”

The findings appeared in the journal Human Biology.

Steak.

Neanderthal diet revolved around meat, new study finds

Neanderthals may have enjoyed their meat — often.

Steak.

Image via Pixabay.

An international research effort has found that Neanderthals were predominantly meat-eaters. The findings come from isotope analysis performed on Neanderthal remains recovered in France.

Haute cuisine

Our understanding of the Neanderthals has changed profoundly over time. At first, we simply assumed they were brutish, more ape than human. Among other characteristics, the prevailing theory was that their diets were primarily vegetarian — big apes are largely vegetarian, this line of thinking went, so Neanderthals must have been the same, right?

We’ve come a long way since then. Archeological evidence revealed that far from being simple-minded and lacking in general skills and finesse, these ancient humans were quite capable. They enjoyed beauty for beauty’s sake, they developed refined tools, established cultural and spiritual practices, and — as they managed to woo our ancestors into bed/the cave — some were probably quite dashing, as well.

The new study comes to flesh out our understanding of what Neanderthals liked to dine on. The team analyzed proteins from preserved collagen in Neanderthal bones found at two dig sites in France: the remains of a one-year-old baby found at Grotte du Renne, and a tooth from Les Cottés. The results show that Neanderthals were neither vegetarian nor simply content with scavenging meat from the kills of other beasts. In fact, they probably killed said beasts and ate them.

The team reports that the ratios of nitrogen-15 to nitrogen-14 isotopes in the collagen samples are similar to what we’d see today in major meat eaters — wolves or lions, for example. The findings, the team explains, add to the body of evidence pointing to the Neanderthals being predominantly meat eaters.

Nitrogen ratio analysis is a widely-used tool for diet reconstruction in ancient species. Nitrogen is a reliable indicator of an organism’s position in a food chain, as organisms obtain it solely through diet. Higher N-15 to N-14 ratios are indicative of carnivores — who concentrate nitrogen from lower trophic levels through diet. The ratio the team found in the Neanderthal collagen is slightly higher than that found in carnivore remains at Neanderthal sites, which the team takes as evidence the Neanderthal’s high position in their local food webs.

There’s also a growing body of indirect evidence supporting this view, the authors note. Previous discoveries of spears found alongside their remains, as well as evidence of butchered animal bodies, suggests that they were quite adept at hunting and processing game. Neanderthals also likely had a bulkier, thicker thorax than modern humans (that’s us). This constitution allowed for larger kidneys and livers compared to our own, a feature common among animals whose diets are heavy in animal protein.

They note that another possibility is that the high ratios were owed to a diet heavy in mammoth meat, putrefying meat (I hope it was the mammoth), or fish. The team used a novel technique called compound-specific isotope analyses (CSIA) to separately analyze each amino acid found in the collagen. The exact isotope composition of amino acids is heavily influenced by diet.

“Using this technique, we discovered that the Neandertal of Les Cottés had a purely terrestrial carnivore diet: she was not a late weaned child or a regular fish eater [fish was not readily accessible at either site], and her people seem to have mostly hunted reindeers and horses”, says Klervia Jaouen, a researcher at the Max Planck Institute for Evolutionary Anthropology and first author of the study.

“We also confirmed that the Grotte du Renne Neandertal was a breastfeeding baby whose mother was a meat eater”.

Another finding was that Neanderthal diets were likely very stable over time, primarily meat, even after they had started to refine tool-processing techniques (possibly as a consequence of interacting with modern humans).

Taken as a whole, the study explains, these tidbits support the view that meat, particularly that obtained from herbivorous animals, was the main constituent of the Neanderthal diet. Small game was likely predominant on the menu, given that bones of fawns and other similarly-sized animals have been found at numerous Neanderthal dig sites and that smaller game is more readily killed with spears — but, as this study reveals, local food resources likely altered what Neanderthals ate in various areas.

The paper “Exceptionally high δ15N values in collagen single amino acids confirm Neandertals as high-trophic level carnivores” has been published in the journal PNAS.

Neanderthal footprints discovered in Gibraltar

Using an optical technique, researchers have identified numerous mammal footprints in Gibraltar — including one that seems to come from a Neanderthal.

The place where the footprint was found. Image credits: Universidad de Sevilla.

“In this work we present the first record of fossil footprints of terrestrial mammals in the Late Pleistocene coastal aeolian deposits of Gibraltar (southern Iberian Peninsula),” researchers write.

For the past 10 years, researchers from Gibraltar, Spain, Portugal, and Japan have been analyzing aeolianites — rocks formed by the solidifying of sediment deposited by aeolian processes (that is, wind). Most such rocks come from coastal limestones, just like is the case in Gibraltar.

The Gibraltar aeolianites are riddled with footprints from vertebrates that used to inhabit the area some 28-31,000 years ago. The footprints correspond to Red Deer, Ibex, Aurochs, Leopard and Straight-tusked Elephant — iconic mammal megafauna that lives alongside early humans. In a new study, researchers describe what they believe to be the footprint of another mammal that inhabited the area: Neanderthals.

A 3D model of the single track described as Hominipes isp. seen from different angles. A and D. Different oblique views of the microtopographic representation of the track with false colors (hot colors represent higher areas, cold colors the lower areas and the dark ones correspond to the printed horizon). Image credits: Muñiz et al.

Of course, much of the sediment in and around the footprint has been eroded, and it’s not clearly visible to the naked eye. So the team used a technique called Optically stimulated luminescence (OSL) to date the footprint and get a better view of it. OSL is somewhat analogous to radiocarbon dating, the main difference being that radiocarbon dating is used to date organic materials, while OSL is used to date minerals.

The Neanderthals in Gibraltar are well known, being among the first to be discovered by modern scientists. They’ve been thoroughly studied, and most anthropologists believe that the Iberian Peninsula and Gibraltar acted as a “refuge” for the shrinking Neanderthal populations in the area.

If the footprint is confirmed to be Neanderthal, it would only be the second one in the world, the other being Vartop Cave in Romania. There are rare documented examples of human footprints in coastal aeolianites, but Neanderthal footprints have turned out to be much more elusive.

Researchers hope that this can be another piece of the puzzle that allows us to understand these close relatives of ours, their culture, and ultimately — what led to their demise. In a way, though, Neanderthals still live through us: it is suggested that 20 percent of Neanderthal DNA survived in modern humans, notably expressed in the skin, hair, and diseases of modern people.

Journal Reference: Fernando Muñiz et al. Following the last Neanderthals: Mammal tracks in Late Pleistocene coastal dunes of Gibraltar (S Iberian Peninsula)Quaternary Science Reviews, 2019; DOI: 10.1016/j.quascirev.2019.01.013

 

Archaeologists uncover timeline of Denisova Cave occupation

The Denisovans were, anthropologically speaking, our cousins. They shared a common origin with Neanderthals and ranged from Siberia to Southeast Asia. They lived along with humans, interbreeding with them on multiple occasions. However, we’ve only found direct evidence of their existence in a cave called Denisova. Now, researchers have detailed the timeline of that cave’s occupation.

Natalia Belousova (Russian Academy of Sciences) and Tom Higham taking samples from the Main Chamber at Denisova Cave
Image credits: Sergey Zelinski, Russian Academy of Sciences

In the lush but cold forests of the Altai Mountains in Siberia, there lies a unique cave. You might not think too much of it seeing it from the outside, but its inside hosts some of the greatest anthropological finds of all time.

The Denisovans were a hominin species whose fossils are known only from a few fragments of bone and teeth unearthed in the Denisova Cave. The excavations and subsequent studies have already provided many insights into this population, but the complex and intricate cave has made it difficult to map the entire timeline of the occupation.

Now, two new papers published in Nature analyze that timeline and provide us with a general picture of the cave’s history.

“Denisova Cave, uniquely, contains stratified deposits that preserve skeletal and genetic evidence of both hominins, artefacts made from stone and other materials, and a range of animal and plant remains,” write Zenobia Jacobs, Richard Roberts, and colleagues, who authored the first paper. “Here, we describe the stratigraphic sequences in Denisova Cave, establish a chronology for the Pleistocene deposits and associated remains from optical dating of the cave sediments, and reconstruct the environmental context of hominin occupation of the site from around 300,000 to 20,000 years ago,” they continue.

Laser beam used for optical dating at the University of Wollongong, Australia.
Image Credits: Erich Fisher.

The optical dating they refer to works by estimating how much time has passed since specific mineral grains (most notably quartz) were last exposed to light. This would correspond to the period when the minerals were brought into the cave. Overall, the authors analyzed the remains of 27 species of large vertebrate, 100 species of small vertebrate (such as mammals and fishes) and 72 species of plant.

Using this method, they found that Denisovans occupied the cave approximately 287,000 to 55,000 years ago. They also confirmed that the cave housed not only Denisovans, but also Neanderthals, who were in the cave from 193,000 to 97,000 years ago. This means that there’s a long period of time where both Denisovans and Neanderthals occupied the cave.

Bone points and pierced teeth from the early Upper Palaeolithic layers of Denisova Cave sampled for radiocarbon dating Image credits: Katerina Douka.

In an accompanying News&Views article also published in Nature, prehistoric archaeologist Robin Dennell, who was not involved in the study, comments:

“Although there might still be some uncertainty about the detailed ages of the remains — given the nature and complexity of the deposits and the dating methods used — the general picture is now clear. Deposition of sediment deposits at Denisova was episodic but [..] the site was occupied by Denisovans and by Neanderthals in both cold and warm periods from approximately 200,000 to 50,000 years ago.”

In a separate paper, Oxford’s Katerina Douka and colleagues present three new fossil fragments, as well as new radiocarbon dates of Denisovan bone, and artifacts also made from bone. Based on the distribution and dating of Denisovan fossils, they conclude that the population inhabited the cave since at least 195,000 years ago. Notably, carbon dating of bone points and tooth pendants indicate an age of 43-49,000 years old, which would make them the oldest artifacts ever unearthed in northern Eurasia. Although this is sti uncear, there’s also a good chance that these artifacts were crafted by the Denisovans.

We are just scratching the surface of who the Denisovans were, researchers emphasize.

“There is still much to learn from Denisova. The work by Douka, Jacobs and their respective colleagues creates an important foundation for such efforts by providing a rigorous and compelling timeline for the cave sediments and its contents,” Donnell concludes.

Journal Reference:

  1. Jacobs et al. “Timing of archaic hominin occupation of Denisova Cave in southern Siberia.” Nature, DOI: 10.1038/s41586-018-0843-2.
  2. Douka et al. “Age estimates for hominin fossils and the onset of the Upper Palaeolithic at Denisova Cave.” Nature, DOI: 10.1038/s41586-018-0870-z.
This image shows a CT scan of the Neandertal fossil (left) with a typical elongated endocranial imprint (red) and a CT scan of a modern human (right) showing the characteristic globular endocranial shape (blue). Credit: Philipp Gunz.

Neanderthal genes may explain our unique rounded skull shape

This image shows a CT scan of the Neandertal fossil (left) with a typical elongated endocranial imprint (red) and a CT scan of a modern human (right) showing the characteristic globular endocranial shape (blue). Credit: Philipp Gunz.

This image shows a CT scan of the Neandertal fossil (left) with a typical elongated endocranial imprint (red) and a CT scan of a modern human (right) showing the characteristic globular endocranial shape (blue). Credit: Philipp Gunz.

Compared to our early ancestors, we humans have unusually round, or ‘globular’, skulls. Neanderthals, with whom humans interbred, have elongated skulls, which are typical of all other primates besides Homo sapiens. Remarkably, it may be the two genes inherited from Neanderthals that may explain our weirdly round skulls, say researchers in a new study published this week.

How Neanderthals may offer clues about human brain evolution

About 2% of the DNA of people living outside Sub-Saharan Africa is Neanderthal. This DNA that we’ve inherited from multiple interbreeding events among dispersed populations can affect skin tone and hair color, height, sleeping patterns, mood, and even smoking status. Neanderthal and Denisovan genes are also responsible for a slew of diseases that plague mankind, such as type 2 diabetes, Crohn’s disease, lupus, allergies, and more. But we’re only beginning to scratch the surface of our Neanderthalian legacy.

An international team of researchers led by Philipp Gunz, a paleoanthropologist at the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, investigated what may have shaped the skulls of modern humans. Globularity (round skull shape) is thought to reflect evolutionary changes in the relative sizes of structures of the human brain. But since brain tissue doesn’t fossilize, it can be challenging to identify an underlying biological mechanism.

The researchers turned to a novel strategy in order to answer this question. Their approach involved analyzing fossil skulls, ancient genomes, but also brain images — quite the interdisciplinary effort.

While all present-day humans exhibit globularity, there is significant variability in skull shape among populations — in other words, some skulls are ’rounder’ than others. By comparing computed tomographic scans of Neanderthal skulls and those of modern humans, the researchers developed a single measure of globularity. Later, thousands of brain scans were analyzed, along with the genomes belonging to 4,500 participants, so that researchers might associate skull shape to certain genes.

The analysis revealed that Neanderthal DNA fragments on chromosomes 1 and 18 were associated with more elongated brains. The same fragments are believed to alter activity in two genes: UBR4 and PHLPP1, both playing important roles in brain development. Specifically, these genes affect the formation of new nerve cells and their insulation in the basal ganglia (also known as putamen) and the cerebellum.

“We know from other studies that completely disrupting UBR4 or PHLPP1 can have major consequences for brain development,” said senior author Simon Fisher, a geneticist at the Max Planck Institute for Psycholinguistics. “Here we found that, in carriers of the relevant Neandertal fragment, UBR4 is slightly down-regulated in the putamen. For carriers of the Neandertal PHLPP1 fragment, gene expression is slightly higher in the cerebellum, which would be predicted to have a dampening effect on cerebellar myelination.”

The effects of these Neanderthal DNA fragments are subtle but by analyzing a large enough sample size, the researchers were able to tease them out. Yet, that doesn’t mean that globularity is explained by Neanderthal interbreeding. Like many other traits, globularity is likely the result of a combination of different genetic variants.

Gunz is careful to note that having an elongated skull does not necessarily mean that such individuals have more Neanderthal DNA, nor do the findings suggest that behavior can be explained by skull shape.

“The focus of our study is on understanding the unusual brain shape of modern humans. These results cannot be used to make inferences about what Neandertals could or could not do,” he said in a statement.

In the future, the researchers plan to re-do the analysis on tens of thousands of people in order to find more genes associated with cranial roundness and other biological characteristics.

“The interdisciplinary approach that we developed for this study could be applied more broadly to unresolved questions about human brain evolution,” says Fisher.

The findings appeared in the journal Current Biology.

Neanderthal life wasn’t more violent than human life, new study suggests

Contrary to a popular stereotype, Neanderthals weren’t violent brutes — a new study reports that Neanderthals and modern humans who lived between 80,000 and 20,000 years ago had similar levels of head trauma, indicating that Neanderthals weren’t more violent than humans.

Neanderthals are commonly thought to have relied on dangerous close range hunting techniques, using non-projectile weapons like the thrusting spears depicted here. Image credits: Gleiver Prieto & Katerina Harvati

The life of Neanderthals, humanity’s closest relatives, has long been misportrayed. They were long thought to be less intelligent and more violent than humans, something which has long been disproved by a number of studies; they were actually compassionate and capable caregivers, followed artistic pursuits, and were overall just as intelligent as humans, if not more so.

Another long-held idea was that Neanderthals was more violent. However, this idea was either baseless, or relying on simple case studies on Neanderthal skeletons (so based on isolated evidence). Now, researchers have carried out a population-wide assessment, comparing the incidence of head trauma incidence in Neanderthal and human populations living in broadly the same period.

Researchers from Tübingen University found that Neanderthals had a high incidence of head trauma, possibly due to violent social behavior or a hunter-gatherer-lifestyle in Ice Age environments where accidents would be common, as would attacks by carnivores such as cave bears or cave hyenas. Additional head injuries could have also been caused by having less advanced weapons, which would have made hunting more dangerous and risk-prone. But humans had just as much head trauma.

“Our findings refute the hypothesis that Neanderthals were more prone to head injuries than modern humans, contrary to common perception”, explains Professor Katerina Harvati, one of the study authors. “We therefore believe that the commonly cited Neanderthal behaviors leading to high injury levels, such as violent behavior and inferior hunting capabilities, must be reconsidered.”

Neanderthal (left) and modern human skeleton. Neanderthals have commonly be considered to show high incidences of trauma compared to modern humans. Image credits: Ian Tattersall

For both humans and Neanderthals, there were substantial differences between men and women — presumably due to the division of labor and potential cultural differences. However, there was a main difference between the two groups: age. The skull trauma incidence was higher among young Neanderthals, whereas for humans, it remained constant across all age groups.

“While Neanderthals and Upper Paleolithic modern humans exhibited a similar prevalence of trauma overall, we found a different age-related trauma prevalence for each species”, explains Judith Beier, first author of the study. This could mean that Neanderthals were more likely to be injured at a younger age than Upper Paleolithic.

This article is unlikely to settle the debate, however. For example, it’s possible that Neanderthals accumulated more injuries to their bodies than their heads — but thus far, the data seems to suggest yet another similarity between Neanderthals and humans.

The study was published in Nature.
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Starting from a seemingly simple tooth, researchers were able to learn much about the lives of Neanderthal children. Credit: Tanya Smith & Daniel Green.

Neanderthal children endured harsh winters and lead poisoning 250,000 years ago

Starting from a seemingly simple tooth, researchers were able to learn much about the lives of Neanderthal children. Credit: Tanya Smith & Daniel Green.

Starting from a seemingly simple tooth, researchers were able to learn much about the lives of Neanderthal children. Credit: Tanya Smith & Daniel Green.

There’s much we don’t know about how our close cousins, the Neanderthals, lived and interacted among themselves. A one-of-a-kind new study is filling in the blanks, providing unprecedented insight into the lives of Neanderthal children. The teeth of two juveniles who lived 250,000 years ago in France suggest that their childhoods were pretty rough, going through much harsher winters than modern humans had experienced. They even were exposed to lead poisoning — the first such instance recorded in a human relative. But despite the numerous hardships, their mothers seem to have done the very best they could.

Nursing Neanderthal kids

The fossilized teeth belonging to the two Neanderthal children were recovered Payre, a site in the Rhone Valley, southeast France. Tanya Smith, a biological anthropologist at Griffith University in Australia, along with colleagues performed a CT scan of the remains and then cut each tooth into thin slices. Like tree rings, teeth record the diet as well as the climate of the individual in each daily growth line of enamel. The results were then compared to the teeth of a modern human child who lived 5,400 years ago at the same site.

Barium isotopes — a marker for milk consumption — told Smith and colleagues that the Neanderthal young were nursed by their mother until they were 2.5 years of age. According to the research team, that’s about just as long as modern humans in hunter-gatherer societies nurse their babies.

The ratio of different isotopes of oxygen found in the layers of the children’s teeth shows that the Neanderthal young lived through colder winters and more seasonal variation in climate than modern humans who lived more recently at the same site. This assertion fits with evidence that scientists previously gathered suggesting that modern humans lived through a much stabler climate in the past 10,000 years.

A 250,000-year-old Neanderthal tooth yields an unprecedented record of the seasons of birth (age 0), nursing (yellow box), illness (red line) and lead exposures (blue lines) over the first 2.8 years of this child’s life. Oxygen isotope values sampled on a weekly basis are shown as a ratio of heavy to light variants. Credit: Smith et al, Science Advances.

A 250,000-year-old Neanderthal tooth yields an unprecedented record of the seasons of birth (age 0), nursing (yellow box), illness (red line) and lead exposures (blue lines) over the first 2.8 years of this child’s life. Oxygen isotope values sampled on a weekly basis are shown as a ratio of heavy to light variants. Credit: Smith et al, Science Advances.

“Our approach is based on the fact that two naturally-occurring atomic variants of oxygen vary in predictable ways. During prolonged periods of warm weather, surface water is higher in the heavy variant of oxygen. The opposite pattern occurs during cool periods. When individuals drink from streams or pools of water, values from these sources are recorded in the hard mineral component of forming teeth,” Smith wrote in The Conversation.

The children were exposed to lead at least twice during their early lifetimes, likely due to food and water with contaminants from nearby lead mines, only 25 kilometers from the archaeological site.

Although the researchers didn’t study adult remains, the findings nevertheless tell us quite a lot about some invisible heroes — the Neanderthal mothers who, despite great hardship, took care of their young as best as they could, perhaps nursing them as carefully as human mothers would.

In the future, the researchers plan on performing the same dental thinning and isotope analysis technique on other specimens and even other types of humans.

“Traditionally, people thought lead exposure occurred in populations only after industrialization, but these results show it happened prehistorically, before lead had been widely released into the environment,” Christine Austin, Assistant Professor at the Icahn School of Medicine at Mount Sinai and co-author of the new study, said in a statement. “Our team plans to analyze more teeth from our ancestors and investigate how lead exposures may have affected their health and how that may relate to how our bodies respond to lead today.”

“Dietary patterns in our early life have far reaching consequences for our health, and by understanding how breastfeeding evolved we can help guide the current population on what is good breastfeeding practice,” said Manish Arora, Professor and Vice Chairman Department of Environmental Medicine and Public Health at the Icahn School of Medicine. “Our research team is working on applying these techniques in contemporary populations to study how breastfeeding alters health trajectories including those of neurodevelopment, cardiac health and other high priority health outcomes.”

The findings appeared in the journal Science Advances.

Neanderthal child was eaten by giant bird

It’s not clear if the bird killed and ate the child or if it simply found its corpse, but recently-analyzed bones strongly hint at a gruesome story.

You thought modern life was bad. Image credits: PAP/Jacek Bednarczyk.

About 115,000 years ago, a Neanderthal child had a really bad day What killed the child is not clear, but what is clear is that his body (or at least some parts of it) were ingested by a large, prehistoric bird — his phalanges (finger bones) passed “through the digestive system of a large bird,” Paweł Valde-Nowak, a professor of archaeology at Jagiellonian University in Kraków, Poland, said in a statement.

“This is the first such known example from the ice age,” he added.

The bones themselves are pretty old — two times older than any other Neanderthal remains found in the area.

“The bones our team discovered in Cave Ciemna are the oldest human remains from the area of today`s Poland, they are about 115,000 years old” said Valde-Nowak.

But age is not what makes the bones stand out.

From the very first inspection, researchers noticed something unusual: the bones seemed to be dotted with many small holes, similar to a strainer. A closer analysis revealed that the child was aged between 5 and 7, with bones about 1 cm long. But the analysis also revealed something else, much darker: the small holes were caused by passage through a bird’s digestive system.

“Analyses show that this is the result of passing through the digestive system of a large bird. This is the first such known example from the Ice Age” – says Prof. Valde-Nowak.

In other words, the unfortunate Neanderthal child was eaten by a bird.

Digging in the cave. Image credits: PAP/Jacek Bednarczyk.

It is possible that the bird actually hunted and killed the child while it was unsupervised, or it could have simply been a scavenger. At this point, neither hypothesis can be ruled out, and both are quite plausible.

The bones are too deteriorated to yield any useful DNA information, but anthropologists are certain they belong to a Neanderthal.

“We have no doubts that these are Neanderthal remains, because they come from a very deep layer of the cave, a few meters below the present surface. This layer also contains typical stone tools used by the Neanderthal,” adds Valde-Nowak.

This gruesome story might be useful for researchers, who are trying to figure out how Neanderthals moved around Europe. They probably appeared in Poland (as in the rest of the continent) around 300,000 years ago. The oldest stone tools they used, discovered on the Vistula, are over 200,000 years old. But we’re not really sure how much they lived.

“Unfortunately, we do not have strong arguments in this discussion,” the archaeologist concludes.

The study has been published in the Journal of Anthropology & Archaeology.

Modern humans and Neanderthals.

Neanderthals gave humans viruses, but also the genes that protect us from them

Neanderthals and humans were so closely related that viruses easily jumped between the two species — but despite the obvious downsides, the interbreeding also gave us humans Neanderthal genes that prime the immune system against the viruses.

Modern humans and Neanderthals.

Credit: Claire Scully.

Neanderthals lived outside of Africa for hundreds of thousands of years, which allowed their immune system to adapt against infectious diseases present in Europe and Asia. However, when humans migrated to Europe for the first time, they were completely vulnerable to ancient RNA viruses. Cue in the interbreeding.

Scientists are confident that the two species interbred at least as early as 50,000 years ago. Everyone in this world, apart from sub-Saharan populations, have up to 2% Neanderthal DNA as a result of this intimate encounter between the two species.

In order to find evidence of ancient diseases that once affected our species, researchers at Stanford University combed through the human genome, zooming in on 4,500 genes in modern humans that are known to interact in some way with viruses, which the researchers compared against a database of sequenced Neanderthal DNA. The analysis identified 152 fragments of those from modern humans that were also found in Neanderthals.

These fragments, which were inherited from Neanderthals, interact with modern day HIV, Influenza A, and Hepatitis C viruses — all of which RNA viruses. The obvious conclusion is that these genes protected us against the ancient variety of RNA viruses that humans must have encountered while they were still fresh out of Africa, the authors reported in the journal Cell. 

“Our research shows that a substantial number of frequently occurring Neanderthal DNA snippets were adaptive for a very cool reason,” Dmitri Petrov, an evolutionary biologist at Stanford’s School of Humanities and Sciences, said in a statement. “Neanderthal genes likely gave us some protection against viruses that our ancestors encountered when they left Africa.”

“It made much more sense for modern humans to just borrow the already adapted genetic defenses from Neanderthals rather than waiting for their own adaptive mutations to develop, which would have taken much more time,” said David Enard, a former postdoctoral fellow in Petrov’s lab.

Neanderthal interbreeding was shaped by viral infections. Credit: Enard & Petrov.

Neanderthal interbreeding was shaped by viral infections. Credit: Enard & Petrov.

What’s more, different viruses influenced genetic swapping between the two species. This makes sense because Neanderthals and modern humans interbred in multiple episodes and in multiple locations throughout prehistory. In each instance, different viruses must have evolved, and so did our defenses.

“It’s similar to paleontology,” Enard. “You can find hints of dinosaurs in different ways. Sometimes you’ll discover actual bones, but sometimes you find only footprints in fossilized mud. Our method is similarly indirect: Because we know which genes interact with which viruses, we can infer the types of viruses responsible for ancient disease outbreaks.”

It’s worth mentioning that the flow of genes and diseases went in both directions. A previous study found that when humans arrived in Europe, they brought with them a slew of tropical diseases that infected ill-prepared Neanderthals.

Elsewhere, at the New York Genome Center, researchers found that HPV16 or genital warts, one of the most common sexually transmitted diseases, came from Neanderthals. After humans and Neanderthals split, each species developed their own HPV strains. Once they met up thousands of years later, though, the Neanderthal variety was acquired by humans and quickly spread.

Type 2 diabetes, Crohn’s disease, lupus, allergies, and other ailments are also believed to be the result of Neanderthal interbreeding.

Credit: Wikimedia Commons.

Extremely cold climate may have sealed Neanderthals’ extinction

Credit: Wikimedia Commons.

Credit: Wikimedia Commons.

Neanderthals were our most closely-related hominin species. They dominated Eurasia for thousands of years before suddenly disappearing around 40,000 years ago — around the time anatomically modern humans began to expand far and wide on the continent.

This prompted scholars to assert that the pressure our species exerted on our close Homo cousins eventually brought about their demise. While that may be true, a new study shows that human competition wasn’t the only important challenge Neanderthals faced. The researchers found that around the time Neanderthals started disappearing, the climate in Europe became unforgivingly cold and dry.

Vasile Ersek, a palaeoclimatologist and geochemist at Northumbria University, along with colleagues sampled stalagmites in two Romanian caves to see what the climate looked like in ancient times. We have instrumental records of climate only for the past 100 years or so, and if we want to look deeper into the past, we need to look at other climate records such as ice cores, tree rings, or stalagmites. The latter are particularly useful because stalagmites grow in thin layers each year, and each layer captures what the temperature and humidity looked like at the time of deposition. Therefore, these stalagmite layers can be likened to a natural archive of climate change over many thousands of years.

The stalagmite records suggest that, between 44,000 and 40,000 years ago, the climate in Europe went through successive phases of extreme cold and excessive dryness. During this time, the climate would cycle through periods of very low temperatures for centuries or even millennia at a time, then warming up again very abruptly.

When the researchers compared the paleoclimate records with archaeological records of Neanderthal activity, they found that the cold periods overlapped with the absence of Neanderthal tools. This suggests that climate change played a major role in the decline of the now-extinct species.

“For many years we have wondered what could have caused their demise. Were they pushed ‘over the edge’ by the arrival of modern humans, or were other factors involved? Our study suggests that climate change may have had an important role in the Neanderthal extinction.”

Credit: Pixabay.

Credit: Pixabay.

The reason why Neanderthals may have been wiped out by this period of extreme cold — while humans made through — is that we could adapt to the new conditions. Neanderthals were skilled hunters, toolmakers, and knew how to control fire, just like humans did. However, they also had a less flexible diet, largely consisting of the meat from the animals they hunted. Humans, on the other hand, had incorporated fish and plants into their diet alongside meat. This wider menu may have offered modern humans the edge they needed to survive through harsh times.

“Before now, we did not have climate records from the region where Neanderthals lived which had the necessary age accuracy and resolution to establish a link between when Neanderthals died out and the timing of these extreme cold periods,” he said, “But our findings indicate that the Neanderthal populations successively decreased during the repeated cold stadials.

“When temperatures warmed again, their smaller populations could not expand as their habitat was also being occupied by modern humans and this facilitated a staggered expansion of modern humans into Europe.”

After a number of depopulation-repopulation cycles, the fragile Neanderthals tribes may have become too weak to resist competition with humans — or the next cold cycle. But while the species is now long gone, there’s a bit of Neanderthal left in each of us — about 2% of your DNA is Neanderthal, the remnant of ancient interbreeding between the two species.

The findings appeared in the journal PNAS.

Human hybrid — Ancient human relatives interbred with each other

Ancient human species interbred, new evidence suggests.

Digging in and analyzing in the Denisova Cave. Image credits: Bence Viola/Max Planck Institute for Evolutionary Anthropology.

A rather small and inconspicuous cave in the Altai mountains, Siberia, has revolutionized our understanding of ancient humans. The Denisova cave has yielded some of the most fascinating ancient artifacts and remains, including a new species of hominins — the Denisovans, named so after the cave itself.

The Denisovans were distinct but related to the Neanderthals. Since Neanderthal remains were also found in the cave, this led to speculation that the two groups were living and breeding together, but there was no direct proof — until now.

In a new study, a team of anthropologists describe a small piece of bone belonging to a child whose mother was a Neanderthal and father was a Denisovan. Not only is this an extremely important piece of evidence, but it’s also very unexpected — a needle in a haystack, anthropologically speaking.

“To find a first-generation person of mixed ancestry from these groups is absolutely extraordinary,” says population geneticist Pontus Skoglund at the Francis Crick Institute in London. “It’s really great science coupled with a little bit of luck.”

The new study was led by Viviane Slon and Svante Pääbo of the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany. Along with their colleagues, they carried out a genetic analysis of the piece of bone, finding that 40% of DNA fragments from the specimen matched Neanderthal DNA, while another 40% matched Denisovan DNA. When they sequenced the sample’s mitochondrial DNA, they found that it comes from the Neanderthal lineage. Since mitochondrial DNA is only inherited from the mother, it means that the mother was Neanderthal, which means that the father was a Denisovan.

But there is another possibility: what if both parents were hybrids themselves?

Denisova Cave.

To figure out which of the two options were more likely, researchers looked at which sections matched which type of DNA. Again, the results aligned surprisingly well, clearly indicating that Denny — as the ancient human was unofficially named — was the direct offspring of two distinct humans, not hybrids. Denny is a first-generation hybrid, and the results, Skoglund told Nature, need to go directly into the history books.

It’s not clear how common interbreeding was, but it seems plausible that both Neanderthals and Denisovans would have jumped at the possibility of breeding with each other. So why haven’t we found more evidence for it, then?

There are a few reasons, starting with the fact that they come from different geographical ranges. In other words, Denisovans and Neanderthals might have simply not met all that often. Also, there’s a chance that hybrids wouldn’t have been fertile, preventing the two groups from truly merging.

Until some 40,000 years ago, Europe was home to both groups. The more well-known Neanderthals were more present in the West, while the elusive Denisovans retreated to the East.

The study was published in Nature.

Engraved Crimean flint could point to Neanderthal symbolism

Some 35,000 years ago, a Neanderthal carved some lines into a piece of rock, immortalizing what researchers now believe to be evidence that his kind was capable of symbolic thought.

The engraved flint researchers analyzed (top) and a reconstruction (bottom). Image credits: Majkic et al., 2018.

The idea of an unthinking Neanderthal brute has long been disproven by now. We now have clear evidence that Neanderthals were just as intelligent and capable as early humans, if not more so. Now, there is growing evidence that aside from being quite capable, Neanderthals were also capable of symbolic thought — a type of abstract thinking in which symbols or images are used to represent objects, persons, and events that are not present.

In understanding this, carved stone artifacts are extremely important, offering clues on human culture and cognition, as well as abstract thinking. For instance, several sites from the Middle and Lower Paleolithic across Europe and the Middle East have yielded carved flint or chert flakes, including some remarkable findings from Neanderthal sites. But the problem is always the same: how do you determine the action that created the carvings? Was it an accidental scrape, or a purposeful engraving? If it was purposeful, was it a practical purpose, a ritual, or something completely different?

To solve these questions, Ana Majkic from the University of Bordeaux, France, and colleagues used state of the art instruments to assess the structure and patterns of the engraved ridges, developing a framework of potential causal actions.

They started out with a broad list, Majkic tells ZME Science, considering a wide range of potential sources such as marks left on a cutting board, hammer, grinding stone, or simply a way to recover the flint nodules. They also considered more specific uses, such as a way to indicate to a novice where to strike, doodling, playing some kind of game or communicating a symbolic meaning.

“Even when it is possible to demonstrate that the engravings are ancient and human made, it is often difficult to distinguish incisions resulting from functional activities such as butchery or use as a cutting board, from those produced deliberately, and even more difficult to identify the scope of the latter,” researchers write.

They carried out a microscopic analysis of the cortex (the soft outer layer of the rock) and the features themselves, moving on to a 3D reconstruction, and started ruling out possibilities. The location of the engraving and the way in which the lines were produced indicated that the rock was engraved after the flake was detached from the core, thus ruling out the causes that may have led to marking the cortex of a nodule. Although flat, the cortex was too small to use as a chopping board. The ridges also aren’t consistent with tools like hammers or axes, and so on. Step by step, they showed not only that the carvings were made with a clear intent, but also that they were made by a skilled individual. The precision with which engraving was executed also indicates very good hand-eye coordination and motor skills employed with effort, attention to detail, and an intent to frame the incise in a particular way.

Lastly, the results were consistent with the “possible representational interpretation of the object” — in other words, it’s plausible that the Neanderthal(s) who made this wanted to symbolically represent something.

“The microscopic analysis and 3D reconstruction of the grooves on the cortex of this small flint flake, demonstrate that the incisions represent a deliberate engraving made by a skilled craftsman, probably with two different points. The lines are nearly perfectly framed into the cortex, testifying of well controlled motions. This is especially the case considering the small size of the object, which makes this a difficult task,” the study continues.

“The production of the engraving required excellent neuromotor and volitional control, which implies focused attention. Evaluation of the Kiik-Koba evidence in the light of the proposed interpretative framework supports the view that the engraving was made with a representational intent,” researchers conclude.

Lastly, Majkic and her colleagues hope that the methodology can be extended to other similar artifacts. For now, evidence is piling up that Neanderthals were capable of symbolic representations, but there’s still a long way to go before that can be definitively concluded.

Journal Reference: Majkic A, d’Errico F, Stepanchuk V (2018) Assessing the significance of Palaeolithic engraved cortexes. A case study from the Mousterian site of Kiik-Koba, Crimea. https://doi.org/10.1371/journal.pone.0195049

Credit: Flickr, Paul Hudson.

Why did Neanderthals have such big noses? It helped them adapt to the cold, study says

A new study suggests that the protruding Neanderthalian nose served to warm and humidify the cold, dry air that was typically inhaled in Europe more than 50,000 years ago.

Researchers at the University of New England in Australia performed X-ray computed tomography (CT) scans and built 3-D models of the skulls of Neanderthals, modern humans, and Homo heidelbergensis. The latter is considered the last common ancestor of the former two species.

A computer model that crunched the fluid dynamics physics for each skull shape found that both human and Neanderthal faces “condition air more efficiently” than their ancestor, H. heidelbergensis. This suggests that both species evolved to better withstand cold and dry climates. However, Neanderthals were particularly apt at moving air through their nasal cavity and into the lungs, volume-wise — significantly more than both H. heidelbergensis and modern humans.

This was perhaps an adaption in response to the Neanderthals’ stocky bodies and lifestyle. By one estimate, the typical Neanderthal required as much as 4,480 calories per day just to keep them alive during the freezing European winter, whereas a modern human male needs only 2,500 daily calories.

A 3-D model of a Neanderthal's skull showing well adapted nasal cavities for conditioning air. Credit: Wroe et al.

A 3-D model of a Neanderthal’s skull showing well adapted nasal cavities for conditioning air. Credit: Wroe et al.

With these many calories, the body needs additional oxygen to convert all those sugars, fats, and proteins into energy. This is where a bigger, more efficient nosal cavity comes in handy.

Previously, researchers hypothesized that the Neanderthalian’s face, which includes a wide nose and protruding upper jaw, was built to exert more biting force. However, the computer simulation run by the Australian researchers suggests that Neanderthals were not very strong biters, not compared to humans at least. Bearing this in mind, it seems much more likely that the Neanderthalian facial architecture was driven, at least in part, by the need to adapt to a cold environment.

“Neanderthals looked very different to us,” said Stephen Wroe, lead author of the new study. “They were shorter, far more robust and muscular than your average modern human, and, perhaps most obviously, they had huge noses and long mid-faces.

“This projecting mid-face is a true Neanderthal novelty, a specialisation which sets them apart, not just from us, but from their ancestors too.”

Scientific reference: Computer simulations show that Neanderthal facial morphology represents adaptation to cold and high energy demands, but not heavy biting, Proceedings of the Royal Society Brspb.royalsocietypublishing.or … .1098/rspb.2018.0085.

Two waves of Denisovan ancestry have shaped present-day humans. Credit: Browning et al./Cell.

Modern humans and Denisovans interbred at least twice in history

In 2010, scientists announced the discovery of an extinct species of Ice Age humans called Denisovans, known only from bits of DNA taken from a sliver of bone in the Denisova Cave in Siberia. Recent research suggests that our Homo sapiens ancestors were intimately in contact with Denisovans. According to a new paper published by researchers at the University of Washington in Seattle, there were at least two distinct episodes of Denisovan genetic intermixing between the two species.

Two waves of Denisovan ancestry have shaped present-day humans. Credit: Browning et al./Cell.

Two waves of Denisovan ancestry have shaped present-day humans. Credit: Browning et al./Cell.

It was first shown that humans interbred with Neanderthals 50,000 years ago100,000 years ago. Later, a 2016 study found that Oceanic individuals hold substantial amounts of not only Neanderthal, but also Denisovan DNA. For instance, the inhabitants of Melanesia, a subregion of Oceania, have between 4% and 6% Denisovan DNA. This fact itself is intriguing because we’re talking about an isolated population on a relatively inaccessible island, thousands of miles away from the Altai Mountains in Siberia.

Sharon Browning, a research professor of biostatistics at the University of Washington School of Public Health, along with colleagues studied 5,600 whole-genome sequences analyzed from individuals from Europe, Asia, America, and Oceania, then compared them to the Denisovan genome.

The analysis revealed that the genomes of two groups of modern humans with Denisovan ancestry are uniquely different, suggesting there were two separate episodes of Denisovan admixture. Specifically, the analysis showed that modern Papuan individuals contain approximately 5% Denisovan ancestry, while East Asians carry about 0.2% Denisovan DNA. It’s not yet clear what effects this Denisovan ancestry might pose to both populations, Browning told me.

“The major challenge was in developing a statistical method for detecting segments of archaic introgression in modern human genomes that would be sensitive (able to find such segments), specific (not yielding a lot of false positive results) and computationally efficient for analysis of thousands of modern human genomes. We spent a lot of time working on our method, testing it on simulated and real data, to address these challenges,” Browning told ZME Science.

Scientists were already aware that Papuans had significant amounts of Denisovan ancestry and that East Asians also bore signs of this admixture, but to a lesser degree. However, the assumption was that the Asian Denisovan ancestry was achieved from an admixture with an Oceanic population. The new work shows that this was not the case. Instead, East Asian populations must have interbred with Denisovans in a separate event, judging from the presence of a second set of Denisovan ancestry that could not be found in South Asians and Papuans. “This result was unexpected,” Browning said.

“When we compared pieces of DNA from the Papuans against the Denisovan genome, many sequences were similar enough to declare a match, but some of the DNA sequences in the East Asians, notably Han Chinese, Chinese Dai, and Japanese, were a much closer match with the Denisovan,” she said in a statement.

Browning thinks it’s possible that the ancestors of today’s Oceanians admixed with a southern group of Denisovans while the ancestors of East Asians admixed with a northern group. Perhaps upcoming studies of other Asian populations, as well as others throughout the world like Native Americans and Africans, might shed valuable new clues.

“We plan to apply our methodology to further worldwide populations, and see if we can find traces of introgression from archaic humans other than Neanderthals and Denisovans,” Browning told me, adding that “Our work helps to further reveal the complexity of human demographic history.”

Scientific reference: Cell, Browning, SR, et al: “Analysis of Human Sequence Data Reveals Two Pulses of Archaic Denisovan Admixture.

Neanderthals were compassionate caregivers, researchers suggest

Homo neanderthalensis, adult male. Reconstruction based on Shanidar 1 by John Gurche

Neanderthals are seen as brutish and uncaring, but a new archeological study has shown that Neanderthals benefited from an effective and knowledgeable healthcare system.

Researchers from the University of York revealed that Neanderthal healthcare was uncalculated and highly effective, even though we tend to think of about them as crueler than modern-day humans. The study suggests that Neanderthals were very compassionate caregivers.

The scientific community knows very well that Neanderthals sometimes provided care for the injured, but the team at York re-analyzed Neanderthal behavior and they suggest ‘our cousins’ were genuinely caring of their peers regardless of the level of illness or injury, rather than helping others out of self-interest.

Lead author, Dr. Penny Spikins, senior lecturer in the Archaeology of Human Origin at the University of York, said, “Our findings suggest Neanderthals didn’t think in terms of whether others might repay their efforts, they just responded to their feelings about seeing their loved ones suffering.”

The individuals researchers know about had a severe injury or disease, with detailed pathologies highlighting a range of debilitating conditions and injuries. Sometimes, the injuries occurred long before the time of death and would have required monitoring, massage, fever management and hygiene care, researchers suggest.

Researchers analyzed a male around 25-40 years old at time of death that showed a catalog of poor health, including a degenerative disease of the spine and shoulders. His degrading physical state would have sapped his strength over the final 12 months of life and severely restricted his ability to contribute to the community. The authors of the study believe he remained part of the group since his articulated remains were subsequently carefully buried.

Dr Spikins added, “We argue that the social significance of the broader pattern of healthcare has been overlooked and interpretations of a limited or calculated response to healthcare have been influenced by preconceptions of Neanderthals as being ‘different’ and even brutish. However, a detailed consideration of the evidence in its social and cultural context reveals a different picture.

“The very similarity of Neanderthal healthcare to that of later periods has important implications. We argue that organised, knowledgeable and caring healthcare is not unique to our species but rather has a long evolutionary history.”

The paper was published in the journal World Archaeology.

Neanderthals were artists just like humans, and even understood symbolism

As early as 64,000 years ago, Neanderthals in today’s Spain were creating impressive cave paintings, showing that they were just as artistic and creative as humans.

The ladder shape composed of red horizontal and vertical lines (center left) dates to older than 64,000 years and was made by Neanderthals. Image credits: P. Saura.

Essentially human

Neanderthals, our closest biological relatives, were extremely similar to us. They shared common behaviors, common characteristics, and even common territory to early humans. They were also much more sophisticated than most people give them credit for.

But they might have also shared something else with our ancestors, something which we consider fundamentally human: our ability to understand symbolism.

“The emergence of symbolic material culture represents a fundamental threshold in the evolution of humankind. It is one of the main pillars of what makes us human”, says Dirk Hoffmann of the Max Planck Institute for Evolutionary Anthropology. “Artefacts whose functional value lies not so much in their practical but rather in their symbolic use are proxies for fundamental aspects of human cognition as we know it.”

A team of researchers from the UK, Germany, Spain, and France analyzed carbonate samples from three cave sites in Spain: La Pasiega (north-eastern Spain), Maltravieso (western Spain) and Ardales (south-western Spain).

All three caves contain spectacular red or black cave paintings depicting animals, dots and geometric signs, as well as hand stencils, handprints and engravings.

These aren’t necessarily new findings, but for the first time, researchers have been able to prove that they must have been made by Neanderthals, since they were the only ones around when the cave paintings were made.

Three hand stencils (center right, center topm and top left). One has been dated to at least 66,000 years ago and must have been made by a Neanderthal. Image credits: H. Collado.

The team used a dating technique that isn’t commonly employed in anthropology: Uranium-Thorium dating. This dating technique relies on analyzing the isotopic content of the two elements and dating the sample by calculating the decay of Uranium 234 into Thorium 230. The technique is widely used to date calcium carbonate materials such as stalactites or corals, but was only recently implemented to anthropology thanks to technological advancements. Radiocarbon technique, which is currently much more common, isn’t able to date back far enough.

The team dated the paintings to 64,000 years ago — 20,000 years before humans modern humans arrived in Europe. This means that Neanderthals were the artists behind the paintings.

“Our dating results show that the cave art at these three sites in Spain is much older than previously thought”, says team member Alistair Pike from the University of Southampton. “With an age in excess of 64,000 years it predates the earliest traces of modern humans in Europe by more than 20,000 years. The cave art must thus have been created by Neanderthals.”

“Dating cave art accurately and precisely, but without destroying it, has so far been difficult to accomplish”, adds Hoffmann. “Thanks to recent technical developments we can now obtain a minimum age for cave art using Uranium-Thorium (U-Th) dating of carbonate crusts overlying the pigments.”

Artistic thinking

This is the first time any evidence of a Neanderthal cave painting has been found — until now, this artform had been considered human and human alone. There has been some evidence that Neanderthals used body ornamentation around 40,000 to 45,000 years ago, but some researchers believed that they learned the idea from humans, a theory which was almost impossible to disprove. The only way to clearly show that Neanderthals came up with the idea on their own was to date their work to before they met humans — and that’s exactly what this study does.

Perforated shells have also bee found in cave sediments, dating to between 115,000 and 120,000 years. Image credits: J. Zilhão.

Joint lead author Dr. Chris Standish, an archaeologist at the University of Southampton, said:

“This is an incredibly exciting discovery which suggests Neanderthals were much more sophisticated than is popularly believed.

“Our results show that the paintings we dated are, by far, the oldest known cave art in the world, and were created at least 20,000 years before modern humans arrived in Europe from Africa – therefore they must have been painted by Neanderthals.”

Neanderthals also dyed and decorated marine shells. Perforated shells were found in sediments in Cueva de los Aviones and date to between 115,000 and 120,000 years, indicating that their artistic practices can be traced even further back.

It’s also significant that this is not a one-off accident — paintings were found in three caves 700 km apart, indicating a long-standing tradition passed on from generation to generation. It’s quite possible that many other similar works of art still exist, but we just haven’t found them yet.

“This is certainly just the beginning of a new chapter in the study of ice age rock art”, says Gerd-Christian Weniger of the Foundation Neanderthal Museum Mettmann, one of the leaders of the Ardales excavations.

It’s intriguing to think about it, but this is convincing evidence that humans and Neanderthals shared the same artistic sense and the same ability for symbolic thinking. Neanderthals weren’t the brutes they’re often portrayed as — they were thinkers and artists just like our ancestors.

But this also raises an even more exciting possibility: since both humans and Neanderthals shared creative abilities, it’s possible that they both inherited them from a common ancestor. If this is the case, we might have to look even further — much further — down in history to find where these abilities first appeared.

“According to our new data Neanderthals and modern humans shared symbolic thinking and must have been cognitively indistinguishable”, concludes Joao Zilhao, team member from the Catalan Institution for Research and Advanced Studies in Barcelona and involved in both studies. “On our search for the origins of language and advanced human cognition we must therefore look much farther back in time, more than half a million years ago, to the common ancestor of Neanderthals and modern humans.”

The paper, U-Th dating of carbonate crusts reveals Neandertal origin of Iberian cave art, is due for publication in Science on Friday, 23 February 2018. DOI: 10.1126/science.aap7778.

Excavation sites.

Neandethals in Spain outlived their kin by thousands of years thanks to a big river and an Italian volcano

Neanderthals in Spain lived on for at least 3,000 years after their relatives had died out everywhere else, new research found. The work suggests that human evolution wasn’t a continuous, streamlined process — rather, a “stop-and-go, punctuated, geographically uneven” one.

Stone tools.

Blank production and diagnostic stone tools from the the Mula basin sites.
Image credits Zilhão J. et al., 2017, Heliyon.

The researchers, composed of members from Portugal, Spain, Germany, Austria, and Italy, say their findings point to an alternating and uneven history of human evolution. The team spent over ten years in the field, excavating three new Neanderthal sites in southern Spain, where they discovered evidence of “distinctly Neanderthal materials” dating roughly 37,000 years ago.

Ok, so what?

It’s a thrilling discovery since that’s thousands of years later than the last signs we’ve found of Neanderthals anywhere in western Europe.

“Technology from the Middle Paleolithic in Europe is exclusively associated with the Neanderthals,” said lead author Dr. João Zilhão, from the University of Barcelona. “Even in the adjacent regions of northern Spain and southern France the latest Neanderthal sites are all significantly older.”

The Middle Paleolithic is a sub-division of the stone age, spanning from 300,000 to about 30,000 years ago. This is about the time when anatomically modern humans started migrating out of Africa and integrating with other human species already inhabiting Eurasia — including the Neanderthals.

The process was widely believed to be a continuous process — our ancestors would move in and the locals would be thrilled and start to date them, then some would move on and so on. According to Zilhão’s team, however, this wasn’t the case. Interbreeding was a much more punctual affair, with different evolutionary patterns in different geographical regions.

The paper draws on evidence recovered from three sites across the Mula basin, Spain: Cueva Antón, a cave located in the Mula River valley, as well as Finca Doña Martina and Abrigo de La Boja, two rock-shelters located in the Rambla Perea. The artifacts include stone tools and evidence of their production and use, such as stone cores, stone flakes, débitage (waste from stone tools manufacturing), as well as charcoal. The items were dating using radiocarbon and stratigraphy methods (where possible), revealing that Neanderthals inhabited the region, and overwhelmingly likely all of modern-day Spain, until approximately 37,000 years ago.

Excavation sites.

The Mula basin sites. a) Location of the late Middle Paleolithic sites of Southern and Western Iberia and Ebro basin (1. Cueva Antón; 2. Sima de las Palomas; 3. Gorham’s Cave; 4. Gruta da Oliveira; 5. Foz do Enxarrique).
Image credits Zilhão J. et al., 2017, Heliyon.

The river Ebro likely played a part in keeping Iberian populations isolated from encroaching humans. The explosion of the Phlegraean Fields caldera some 39,850 years ago, with the “population sink it generated in Central and Eastern Europe” and the climatic changes it induced, would have increased the biogeographical divide represented by the river, further stalling the Neandertal/modern human admixture front.

Cueva Antón, they add, is the most recent known site inhabited by Neanderthals in Europe.

The findings showcase the step-by-step process through which anatomically modern humans and preexisting human populations interbred and assimilated throughout Europe — and likey everywhere else, too.

“We believe that the stop-and-go, punctuated, uneven mechanism we propose must have been the rule in human evolution, which helps explaining why Paleolithic material culture tends to form patterns of geographically extensive similarity while Paleolithic genomes tend to show complex ancestry patchworks,” Dr. Zilhão adds.

Ornamental shells.

Ornamental shell across the Middle-to-Upper Paleolithic transition in the Mula basin sites.
Image credits Zilhão J. et al., 2017, Heliyon.

They are also important in the wider context of stone-age archaeological findings in the Iberian Peninsula:

“A corollary of these findings,” the team writes, “carries implications for the authorship of all other aspects of these regions’ archeological record. For instance, given their dating and archeological associations, there can be no question that the painted/perforated shells from Cueva Antón and Cueva de los Aviones, as well as the abstract engraving and ornamental use of raptor feathers documented at Gorham’s Cave, stand for manifestations of Neandertal symbolism.”

He explains that there is still a lot we don’t know about human evolution, the Neanderthals in particular. Most of what we do know comes from populations in France, Germany, and central Europe, but Zilhão comments that during the Ice Age these were “peripheral areas.” It’s likely that over half of the Europeans who lived during the Paleolithic were Iberians, he adds, meaning we’re missing a big chunk of the picture here. An image that ongoing research is trying to piece together, but one that will require ” discovering and analyzing new sites, not in revisiting old ones,” Dr. Zilhão believes.

The paper “Precise dating of the Middle-to-Upper Paleolithic transition in Murcia (Spain) supports late Neandertal persistence in Iberia” has been published in the journal Heliyon.

Neanderthals were doomed to fail, new study suggests

Neanderthals lived at the same time as early humans. They were strong, smart, and in many ways better than their counterparts. Yet humans endured, while Neanderthals went extinct (though in a way, we still carry them around through our DNA). So what killed them?

Migration of species, via Wikipedia.

The extinction of the Neanderthals is a long debate which won’t end anytime soon. This new study doesn’t try to explain if the main culprit was climate change, epidemics, or the inability to compete with humans. Instead, it argues that Neanderthals were doomed to fall either way.

Oren Kolodny of Stanford University approached his colleague Marcus Feldman. Together, they carried out a computer simulation that represented small bands of Neanderthals and modern humans in Europe and Asia. They then sent these populations randomly into extinction, regardless of whether they were Neanderthals or humans. Neither of the populations was considered to have an advantage over the other. However, there was one small, but extremely important difference.

While Neanderthal populations were generally stable, human populations had a small trickle of reinforcements coming in from Africa. This small number of extra bands of humans coming in was enough to tip the balance in the favor of humans.

The computer model is consistent with the anthropological evidence. Neanderthals first emerged in Europe around 400,000 years ago. Sometime between about 51,000 and 39,000 years ago, humans and Neanderthals shared the same landscape. They may have fought and competed for the same resources, they may have gotten along well, and they certainly interbred. When it was all said and done, humans survived, while Neanderthals didn’t. It’s a simple ecological principle: two different species can’t survive occupying the exact same niche at the exact same time. So it’s safe to assume that the former had some kind of selective evolutionary advantage over the latter. But what was it?

Not that different, right? Comparison of Neanderthal and Modern human skulls from the Cleveland Museum of Natural History.

It’s hard to assume what that advantage was, especially as the environmental conditions at the time weren’t precisely known. So Kolodny and Feldman tried to establish a simple model, without any hard-to-prove claims. They ran their simulation more than a million times, changing different assumptions and variables, but almost every time, Neanderthals slowly faded away — all due to the extra migration coming in from Africa.

If survival was a game of chance, “it was rigged by the fact that there’s recurring migration,” Kolodny said. “The game was doomed to end with the Neanderthals losing.”

“We have also demonstrated that even if bidirectional migration between Europe and Africa had occurred, [modern humans] would have been extremely likely to eventually replace Neanderthals, given the estimated differences in population size between the species, in favor of [modern humans].”

This seems to indicate that humans weren’t necessarily better than Neanderthals at any given task — they simply survived by migrating more. This is consistent with previous studies based on physical evidence. These studies found that humans and Neanderthals were much more similar than previously believed.

‘It confirms the so-called “null hypothesis” — based solely on we know about humans and Neanderthals, and considering that the two populations are similar, we can say that Neanderthals were very likely to fail even in the absence of decisive enviromental changes.

However, it’s important to note that this study is suggestive, not conclusive, Kolodny cautioned. However, it does suggest that even without climate change or another environmental change, mankind still would have won the species war.

“Even if there were no selection and no climate change, the end result would have been the same. It’s a subtle distinction but it’s important,” Kolodny concludes.

Journal Reference: Oren Kolodny et al. A parsimonious neutral model suggests Neanderthal replacement was determined by migration and random species drift, Nature Communications (2017). DOI: 10.1038/s41467-017-01043-z .