Tag Archives: homo sapiens

Modern humans ventured into Neanderthal territory much earlier than we thought

Until now, archaeological findings suggested that Neanderthals disappeared from Europe about 40,000 years ago, soon after the arrival of Homo sapiens – with limited evidence of encounters between the two groups. But a new study is now saying otherwise, showing evidence that Homo sapiens ventured into Europe much earlier than we thought, deep into Neanderthal territory. 

Image credit: The researchers.

The discovery of a child’s tooth and hundreds of stone tools at a cave in France by a group of archaeologists and paleoanthropologists pushes back the arrival of Homo sapiens to about 54,000 years ago. The study also showed that the two types of humans alternated in living in the cave, located in the Rhone region of France.

“We’ve often thought that the arrival of modern humans in Europe led to the pretty rapid demise of Neanderthals, but this new evidence suggests that both the appearance of modern humans in Europe and disappearance of Neanderthals is much more complex than that,” study coauthor Chris Stringer said in a press statement.

A long-term project

Since 1990, the team of researchers has been carefully investigating the sediment on the cave floor. The site is a strategic point in the landscape, they argue, as the river Rhone flows through a narrow between two mountain ranges. Inhabitants of the site would have clear views of herds of animals, today replaced by trains and a highway.

The researchers now discovered hundreds of thousands of objects that they attributed to either modern humans or Neanderthals. These included triangular stone points that were used by Homo sapiens to cut or scrape and as spear tips. Similar tools from the same period were found 3,000 kilometers (1,900 miles) away in present-day Lebanon.

Image credit: The researchers.

Dental remains from at least seven individuals across 12 archaeological layers were also found in the cave. The researchers identified six of these individuals as Neanderthal. But there was a surprise. In a layer between the Neanderthal layers, the team found a fossil moral from a modern human child, between two and six years old.

While they couldn’t find evidence of cultural exchanges between modern humans and Neanderthals who alternated the cave, the succession of occupants is significant on its own. It’s the first-time evidence of the two groups living in the same place is found. They rotated quite rapidly, even abruptly, at least twice, according to the study. 

Understanding human history is a tricky process, but an important one. Modern humans originated in Africa and made their first migration between 50,000 to 70,000 years ago. Ancient hominins existed and coexisted before the emergence of Homo sapiens. Some of these groups are identified by fossils, while others by their genetic legacy. 

Many questions now remain after the study, as the researchers explain in a blog post in The Conversation. Did modern humans have a relationship with the Neanderthals, exchanging information for example? Did they interbreed at some point? How did modern humans learn about the stone tools in such a short period of time? 

“The findings are really exciting and are another piece in the puzzle of how and when modern humans arrived in Europe,” Stringer said. “Understanding more about the overlap between modern humans and other hominins in Eurasia is vital to understanding more about their interactions, and how we became the last remaining human species.”

The study was published in the journal Science Advances

Humanity’s direct ancestor gets a new name. Meet Homo Bodoensis

Homo bodoensis. Credit: Ettore Mazza.

You don’t get to pick your parents or your name for that matter, but at least you can legally change the latter if you feel like a name like X Æ A-12 is a bit too embarrassing. In science, species’ names rarely change though. Just imagine how many textbooks you’d have to edit. This is why this week’s announcement that the direct ancestor of our species has been renamed is really a big deal.

From now on, an international team of researchers, led by University of Winnipeg palaeoanthropologist Dr. Mirjana Roksandic, has proposed that our direct human ancestor — an ancestral species of Homo that lived in Africa during the Middle Pleistocene, around half a million years ago — shall be known as Homo bodoensis.

The designation is not based on any new fossils or scientific findings. Instead, the researchers are trying to clarify what is often known as the ‘muddle in the middle’, a problem that refers to the tangled mess of designation and contradictory findings from the Middle Pleistocene. The importance of clearing up this mess cannot be understated as it is during this nebulous period — also known as the Chibanian and dated to 774,000–129,000 years ago — that Homo sapiens and our close extinct cousins the Neanderthals (Homo neanderthalensis) emerged in Africa and Europe, respectively.

“Talking about human evolution during this time period became impossible due to the lack of proper terminology that acknowledges human geographic variation.” Roksandic said in a statement.

Simplified revised family tree of the genus Homo. Credit: Evolutionary Anthropology Issues News and Reviews.

Previously, this ancestral species was known as one of two species: Homo heidelbergensis or Homo rhodesiensis. Right off the bat, it’s easy to understand why they call it a ‘muddle’ seeing how we used to have two species that confusingly referred to a single one. Consequently, Homo heidelbergensis and Homo rhodesiensis have been scrapped from the taxonomy being now redundant to make way for Homo bodoensis, which derives its name from a skull found in Bodo D’ar, Ethiopia.

Under this new and improved classification, H. bodoensis will from now on describe most Middle Pleistocene humans from Africa and some from Southeast Europe, while other specimens found in the rest of Europe will be reclassified as Neanderthals based on modern DNA analysis of fossils.

The case of H. rhodesiensis is even muddier since the species was rather poorly defined, based on a single skull called Kabwe found at Broken Hill in Northern Rhodesia, now Zambia, by Tom Zwiglaar in 1921. Furthermore, the name was never widely accepted by the scientific community, partly due to its association with Cecil Rhodes, an imperialist, businessman, and politician who played a dominant role in southern Africa in the late 19th Century. Rhodes was the prime minister of Cape Colony, from 1890 to 1896, and during his governmentship, the rights of black Africans were severely restricted by raising the financial qualifications for voting. He is also blamed for many horrendous crimes during the British colonial rule of Africa. The fact that such an important ancestral human species is named after Rhodes has been seen as very dishonorable, especially in light of recent attempts to decolonize science.

“Terms need to be clear in science, to facilitate communication. They should not be treated as absolute when they contradict the fossil record,” said co-author Predrag Radović of the University of Belgrade in Serbia.

H. bodoensis is cutting the Gordian knot and allowing us to communicate clearly about this important period in human evolution,” added Christopher Bae of the Department of Anthropology at the University of Hawai’i at Manoa.

Artist impression of male and female Homo bodoensis. Credit: Ettore Mazza.

Based on the damaged facial skeleton of “Bodo 1”, the researchers described H. bodoensis as having a “massive face”, with large rectangular orbits and a very broad interorbital region, a wide nose, and a broad and deep palate. Compared to Homo erectus, whose fossils are the oldest known early humans to have possessed modern human-like features, H. bodoensis had a larger brain, similar to Neanderthals. However, they differed from Neanderthals substantially in other areas, not sharing the same prominent, double-arched brow ridges.

H. bodoensis lacks a number of the H. sapiens specific features—warranting a separate species designation. This is contrary to what is observed in H. neanderthalensis where the autapomorphies emerge early in the Middle Pleistocene. However, all of the later H. sapiens specific features can be derived from traits present in H. bodoensis, including the massive but segmented (divided into lateral and medial parts) brow ridges,” the researchers wrote in their study.

While H. bodoensis serves to clear many confusing aspects of our evolution, it is by no means a magic bullet. Just like humans often interbred with Neanderthals, so did our early ancestors mingle amongst different groups. DNA studies show that humans didn’t evolve from a single ancestral population. We might never be able to pinpoint our closest direct ancestor but, for the time being, H. bodoensis is close enough.

The new designation was described at length in a new study published in the journal Evolutionary Anthropology Issues News and Reviews.

Is the ‘Dragon Man’ a new species of human? Here’s what we know so far

Artist’s impression of Dragon Man. Credit: Chuang Zhao.

Last week, paleontologists in China broke the news that they have identified a 146,000-year-old cranium that may belong to a distinct, up until now unidentified species of humans. This tentative new species, known as Homo longi, or Dragon Man, has a mix of features shared by Neanderthals, Denisovans, and humans. If it is indeed a new species, scientists believe it may be the closest relative to modern humans, replacing the Neanderthals as our closest extinct kin.

The Dragon Man skull

From left to right are the skulls of Peking Man, Maba, Jinniushan, Dali, and Harbin. Credit: Kai Geng.

The skull was found near Harbin, a town in northeast China, in 1933 by bridge construction workers. Its potential importance was missed until 2018 when it reached the hands of a team of paleontologists led by Xijun Ni, a professor of primatology and paleoanthropology at the Chinese Academy of Sciences and Hebei GEO University.

Unlike most other hominin fossilized skulls that are usually crushed and fragmented, the Harbin skull was discovered remarkably intact. Its only major flaw is that it has only one tooth still attached to the mandible, a left molar.

In a series of three papers, the researchers described the extraordinary skull, which could hold a brain comparable in size to modern humans. It features almost square eye sockets beneath a heavy brow ridge reminiscent of the Neanderthals but has a wide face with small, flat cheekbones that is typical of modern humans. The cranium, which scientists believed belonged to a 50-year-old male, also features a wide mouth and oversized teeth.

“The Harbin fossil is one of the most complete human cranial fossils in the world. This fossil preserved many morphological details that are critical for understanding the evolution of the Homo genus and the origin of Homo sapiens. While it shows typical archaic human features, the Harbin cranium presents a mosaic combination of primitive and derived characters setting itself apart from all the other previously named Homo species,” said Qiang Ji, a professor of paleontology at Hebei GEO University.

A new species of human? not so fast

Artist impression of Dragon Man. Credit: The Innovation.

Like modern humans, Homo longi probably hunted mammals and birds, gathered wild fruits and vegetables, and perhaps even caught fish. Considering the Harbin individual was large in stature, as well as the location where it was found, the researchers believed that H. longi was well adapted to harsh environmental conditions.

Geochemical analyses showed that the Harbin man fossils are at least 146,000 years old, placing them well within the Middle Pleistocene, an era when humans were busy dispersing across the world. It is thus very likely that H. longi encountered Homo sapiens, as well as Denisovans and Neanderthals.

“We see multiple evolutionary lineages of Homo species and populations co-existing in Asia, Africa, and Europe during that time. So, if Homo sapiens indeed got to East Asia that early, they could have a chance to interact with H. longi, and since we don’t know when the Harbin group disappeared, there could have been later encounters as well,” says author Chris Stringer, a paleoanthropologist at the Natural History Museum in London.

When the researchers reconstructed the human tree of life to account for H. longi, they found that the tentative new species is even more closely related to us than Neanderthals and represents a sister species. This implies that Homo sapiens must have split from Neanderthals even further back in time, diverging from a common ancestor roughly 400,000 years earlier than scientists had previously thought.

“It is widely believed that the Neanderthal belongs to an extinct lineage that is the closest relative of our own species. However, our discovery suggests that the new lineage we identified that includes Homo longi is the actual sister group of H. sapiens,” says Professor Ni.

But is Homo longi truly a new species of human? It’s a bit too early to tell. The Harbin man may well be a Denisovan, an extinct species of archaic human that ranged across Asia during the Lower and Middle Paleolithic and whose fossil record is very scant. So far, the only fossils we have found of Denisovans include a finger bone, a few teeth and a skull fragment retrieved from Denisova Cave in Siberia, and a jawbone from Xiahe, northern China.

According to Ars Technica, when “Ni and colleagues did their statistical analysis, they pointed out that the Harbin skull fell into a group along with the 160,000-year-old Denisovan mandible from Xiahe. Given the great diversity of shapes and sizes that human skulls come in, it wouldn’t be that surprising for the Harbin skull to actually belong to the range of diversity for Denisovans.

If scientists manage to extract DNA from the Harbin skull, they could then compare it to the genomes of Denisovans, Neanderthals, and modern humans, to which we have access. That would settle at least some of the debate.

In any event, the Harbin skull is hugely significant. If it turns out to be a distinct species, then the human tree of life just got enlarged with one member. If subsequent research shows it is from a Denisovan, then we’ll finally know what these rather mysterious cousins looked like. So a win/win for science.

Neanderthal milk teeth show their babies were raised and weaned similar to us

A model of Neanderthals at the Vienna Natural History Museum. Credit: Wolfgang Sauber.

Here’s another thing where humans and Neanderthals seem to have the same: child-rearing. According to a new study conducted by an international team of researchers, Neanderthals started to wean their infants at around 6 months of age, which is also when modern humans start introducing solid food in the diets of their children.

Ancient milk teeth and Neanderthal parenting

It seems like with each new study on Neanderthals, the conceptual gaps between our close extinct relatives and Homo sapiens seem increasingly narrower. For instance, Neanderthal artifacts like eagle talon necklaces found in Spain were very similar to jewelry made by humans. Their burial practices also suggest that Neanderthals employed many cultural practices mirroring those of humans.

Now, thanks to geochemical and histological analyses of three Neanderthal milk teeth, scientists have gained new insights into Neanderthal parenting.

“How different Neanderthals are to us is a topic currently under intense debate. These ‘cousins’ of ours are important for understanding our evolution but also our future. Being able to understand Neanderthals’ natural history is one of the most stimulating intellectual challenges,” Federico Lugli and Stefano Benazzi, co-authors of the study from the University of Bologna in Italy, told ZME Science.

Credit: Federico Lugli.

The teeth belonged to three different Neanderthal infants who lived between 70,000 and 45,000 years ago in northeastern Italy, a region that has always been rich in food and natural shelters like caves, making it a Neanderthal hotspot for at least 45,000 years.

Like tree rings, growth lines on teeth are deposited on a year by year and reflect the diet of the children. Using laser-mass spectrometry, the researchers measured strontium concentrations in the dental samples, which showed Neanderthals started introducing solid food in their children’s diets at around 5-6 months of age.

“Studies on Neanderthals’ early infancy are few, and they mainly deal with morphology and not with behavior. Our research sheds light on the understanding of how Neanderthal children grew up and how they were fed. Our study highlights a weaning pattern very similar to Homo sapiens and demonstrates once again how much Neanderthals are so similar and yet so different from us,” the researchers told ZME Science.

Across all human cultures, children are weaned at around 6 months of age. Around this time, mother’s milk alone is not enough to supply an infant’s calorie requirements for the growing human brain.

Neanderthal’s metabolic constraints and early development have always been a matter of contention among scholars. The new findings tip the balance of the debate towards more similarities with humans, suggesting that Neanderthal newborns probably had a similar weight to modern human babies. Neanderthal mothers may have also had a similar gestational history and development to human mothers. Previously, a study by researchers at Griffith University in Brisbane, Australia, found that Neanderthal children were fully weaned after the age of two.

“We have already started working on other archaeological contexts to broaden our knowledge of a hidden part of the fossil record, which is the little-known world of Neanderthal children and their mothers. Still, we will apply our methodologies on other fossil and even contemporary humans, actively searching for discrepancies or similarities in parental care and mother-child relationship,” the Italian researchers said.

The findings appeared in the Proceedings of the National Academy of Sciences.

An unknown ancestor mated with ancient humans. Its DNA is found in living people to this day

The unidentified ancient human relative may have been Homo erectus. Credit: flowcomm, Flickr.

To say the sex lives of our ancestors was complicated would be an understatement. After they migrated out of Africa into Eurasia, humans interbred with Neanderthals, Denisovans, and at least one other group of archaic people belonging to our genus. Evidence of this latter interbreeding lives on in our genes, according to a new study by researchers in the United States. The identity of this group is still shrouded in mystery.

When Homo sapiens migrated in large numbers out of Africa through the Middle East into Europe and Asia, they came in contact with the Neanderthals, who had been masters of their domains for thousands of years prior to the arrival of anatomically modern humans. The two species interbred, the effects of which are still seen in the genomes of people alive today who are not of Sub-Saharan heritage. About 2% of the DNA in the genomes of modern-day people with Eurasian ancestry is Neanderthal in origin.

But the gene flow goes both ways, of course. In a new study, Melissa Hubisz and Amy Williams of Cornell University and Adam Siepel of Cold Spring Harbor Laboratory performed a complex genomic analysis of the DNA of two Neanderthals, a Denisovan and two living African humans. The latter have no Neanderthal DNA in their genomes, as opposed to Caucasians, which helped the researchers differentiate patterns of ancient interbreeding.

The team of researchers employed a computational method that enabled them to identify recombination events, in which segments of the chromosomes from one individual become incorporated into the chromosomes of another. This clever method can map out the tree of relationships among individuals at every position along the genome.

In more practical terms, this approach enabled the researchers to uncover previous instances of mating nested in the genomes of living or extant species. For instance, if Neanderthals mated with some other human species, and later these descendants mated with modern humans, this method can uncover that initial instance of ancient interbreeding.

As it turned out, the study revealed some amazing instances of such nested insections of DNA. For instance, 3% of the Neanderthal genomes came from ancient humans, estimated to have occurred 200,000 to 300,000 years ago. This is additional evidence supporting the fact that humans left Africa in multiple waves before making a huge leap out of the continent primarily 50-60,000 years ago. These early migratory waves of humans were likely assimilated by Neanderthals or were wiped out one way or the other.

But the most striking finding was that 1% of the Denisovan DNA came from a yet unidentified species of ancient humans. The interbreeding occurred roughly one million years ago, a timeline that suggests the lover may have been Homo erectus. Sadly, no Homo erectus DNA has ever been found, so this hypothesis remains speculation at this point. It may very well have been some different, yet to be identified species altogether.

In any event, both interbreeding events have been passed down to living modern humans. About 15% of the interbreeding sequences found in the Denisovans are present in living people today, the researchers reported in the journal PLoS Genetics.

Given the sheer number of gene exchanges between ancient humans and their extinct relatives, it’s very likely that genetic exchange took place whenever two distinct groups of humans overlapped in time and space. The same algorithm employed by the study could be used to study gene flow in other species where interbreeding occurred in the distant past, such as between wolves and dogs.

“What I think is exciting about this work is that it demonstrates what you can learn about deep human history by jointly reconstructing the full evolutionary history of a collection of sequences from both modern humans and archaic hominins,” Siepel said in a statement. “This new algorithm that Melissa has developed, ARGweaver-D, is able to reach back further in time than any other computational method I’ve seen. It seems to be especially powerful for detecting ancient introgression.”

Humans, not Neanderthals created oldest modern artifacts in Europe

New studies suggest that humans and Neanderthals co-existed together for far longer than was previously thought.

Stone artifacts from the Initial Upper Paleolithic at Bacho Kiro Cave. 1-3, 5-7: Pointed blades and fragments from Layer I; 4: Sandstone bead with morphology similar to bone beads; 8: The longest complete blade. Credit: Tsenka Tsanova, MPI-EVA Leipzig.

When archaeologists first excavated the Bacho Kiro cave in Bulgaria, they knew they found a valuable trove. Blade-like tools and animal tooth pendants, some preserved in excellent condition. The tools dated to the Upper Paleolithic, some 46,000 years ago.

Initially, archaeologists thought the Neanderthals were responsible. It made a lot of sense: Neanderthals had left stone tools in the same cave 50,000 years ago. But according to a new study, this isn’t really the case. Instead, the artifacts were built by Homo sapiens — which is significant for several reasons.

First of all, it’s the earliest known evidence from a member of our species in Europe. Secondly, it shows that humans and Neanderthals must have overlapped for several millennia, likely influencing each other and quite possibly mating with each other.

“Our findings link the expansion of what were then advanced technologies, such as blade tools and pendants made from teeth and bone, with the spread of Homo sapiens more than 45,000 years ago,” explains Shara Bailey, a professor in NYU’s Department of Anthropology and one of the paper’s co-authors. “This confirms that Homo sapiens were mostly responsible for these ‘modern’ creations and that similarities between these and other sites in which Neanderthals made similar things are due to interaction between the populations.”

Excavations in Initial Upper Paleolithic Layer I at Bacho Kiro Cave (Bulgaria). Four Homo sapiens bones were recovered from this layer along with a rich stone tool assemblage, animal bones, bone tools, and pendants. Credit: Tsenka Tsanova.

To figure out who create these tools, researchers did a bit of detective worth. First, Bailey and her colleagues examined the teeth and bone fragments, dating them to at least 45,000 years ago — a period when multiple waves of Homo sapiens were thought to migrate towards Europe.

Then, other researchers analyzed the shape of the tooth and carried a DNA analysis of the fragments, determining that they belonged to Homo sapiens and not Neanderthals.

This strongly suggests that the artifacts were made by humans, or at the very least, that humans were present at the site. Since Neanderthals didn’t vanish from the area until about 40,000 years ago, the two species overlapped for several millennia — a theory supported by DNA studies which have shown that the two mated on several occasions. However, bones of Homo sapiens in Europe are so scarce that establishing an overlap has proven to be very difficult.

Journal References:

Initial Upper Palaeolithic Homo sapiens from Bacho Kiro Cave, Bulgaria, Nature (2020). DOI: 10.1038/s41586-020-2259-z , www.nature.com/articles/s41586-020-2259-z

A 14C chronology for the Middle to Upper Palaeolithic transition at Bacho Kiro Cave, Bulgaria, Nature Ecology & Evolution, DOI: 10.1038/s41559-020-1136-3 , www.nature.com/articles/s41559-020-1136-3

‘Ghost DNA’ belonging to ancient extinct humans is still alive in the genomes of West Africans

Tens of thousands of years ago, modern humans may have interbred with a yet-to-be-identified related species. We know this because traces of this ancient interbreeding have been transmitted to the genomes of modern-day west African populations, according to a recent study.

Human evolution hasn’t followed a straight line but rather a series of divergent branches. Some of our ancestor’s lineages went extinct entirely, while others branched further.

It’s remarkable to imagine that at one point in time Homo sapiens shared this planet with at least four other lineages: Neanderthals, Denisovans, Homo floresiensis, and perhaps with Homo luzonensis (the latter still awaiting confirmation).

Now, a new study suggests that there may be a fifth lineage of humans. We haven’t found their fossils, but their genes are still very much etched in the genomes of certain west African populations. In some cases, up to a fifth of their DNA comes from these mysterious missing relatives.

The discovery was announced by a team of researchers led by Sriram Sankararaman, a computational biologist at the University of California, Los Angeles, in a new study published in Science Advances.

Sankararaman and colleagues sequenced the genomes of 405 individuals from four West African populations: two from Nigeria, one from Sierra Leone, and one from Gambia.

By employing statistical techniques, the researchers looked for markers of interbreeding that may have occurred in the distant past — turns out it did.

When they compared the African genomes with DNA from Neanderthals and Denisovans, the researchers found a huge chunk of DNA that came from an unidentified group of archaic humans. Their impact was highly substantial, ranging from 2% to 19% of the populations’ genetic ancestry.

“We don’t have a clear identity for this archaic group,” Sankararaman told NPR. “That’s why we use the term ‘ghost.’ It doesn’t seem to be particularly closely related to the groups from which we have genome sequences from.”

These ‘ghost’ people seem to have split from the common ancestor shared with Neanderthals and modern humans between 360,000 and one million years ago. According to the molecular genetic data, as many as 20,000 individuals belonging to this group of archaic humans interbred with the ancestors of modern West African humans at some point in the last 124,000 years.

We don’t know how these human relatives looked like or how they lived, but their genes paint a compelling story of complex interactions with our ancestors. In the process, our own story has suddenly become richer.

There is still much to learn. Next, the researchers plan to focus on some of these genes in order to tease out what they do. It’s very possible that many of these genes were kept across the generations because they provide an adaptive value to West African populations. What would prove to be a gold mine is finding fossils belonging to this mysterious extinct human relatives. Alas, that’s highly challenging since Africa’s climate is not kind on fossil preservation — but one can never know!

Oldest human skull out of Africa forces us to rethink migration timeline

A human skull dating from 210,000 years ago has been shown to be human. The skull was discovered in a Greek cave in the 1970s but was then classified as Neanderthal. A new analysis showed that it is indeed human — and its timeline is absolutely puzzling.

The Apidima 2 cranium (right) and its reconstruction (left). Apidima 2 does belong to a Neanderthal. Image credits: Katerina Harvati, Eberhard Karls University of Tübingen.

It’s easy to understand why the Apidima Cave in Greece was seen as a refuge for ancient humans. Located in southern Greece, it probably offered provided a more stable and warmer climate than most other places, with plenty of water and feeding opportunities around it. Undoubtedly, numerous humans took shelter in the area, though most of them passed without leaving behind a single (archaeological) trail. Two individuals, however, did.

Two fossilized human crania (Apidima 1 and Apidima 2) from Apidima Cave, were discovered in the late 1970s. However, the study of these fossils proved to be extremely challenging. Not only were the skulls broken and fragmented, but up until the 1990s, it was impossible to extract them from the surrounding rock matrix. Even after they were extracted, their analysis remained difficult.

Initially, scientists thought them to be Neanderthal.

Now, an international team of researchers used state-of-the-art computer modeling and uranium dating to re-examine the two skulls. They found that one of them, dating from 170,000 years ago is indeed Neanderthal. But the other one yielded a massive surprise: not only was it 40,000 years older than the other one, but it belonged to a Homo sapiens — not a Neanderthal.

This would make it the oldest out-of-Africa human skull ever discovered.

The Apidima 1 partial cranium (right) and its reconstruction from posterior view (middle) and side view (left). Image credits: Katerina Harvati, Eberhard Karls University of Tübingen.

This is more than just a quirk of history — it puts a new, unexpected constraint on the “Out of Africa” theory, the dominant model of early migration of anatomically modern humans (Homo sapiens).

“It shows that the early dispersal of Homo sapiens out of Africa not only occurred earlier, before 200,000 years ago, but also reached further geographically, all the way to Europe,” Katerina Harvati, a palaeoanthropologist at the Eberhard Karls University of Tuebingen, Germany, told AFP.

“This is something that we did not suspect before, and which has implications for the population movements of these ancient groups,” she added.

It’s generally believed that hominins, a subset of great apes that includes Homo sapiens and Neanderthals, emerged in Africa more than six million years ago. They gradually migrated away from the continent — not at once, but in several migration episodes starting two million years ago. Some 45,000 years ago, Homo sapiens emerged from out of Africa, establishing its dominance and gradually replacing Neanderthals (with episodes of mixing and interbreeding).

The Out Of Africa theory suggests that humans gradually replaced Neanderthals. Image via Wikipedia.

This old skull suggests that an earlier migration also happened way before this timeline, and the overall migration might have happened in multiple waves rather than one big gradual one.

“Rather than a single exit of hominins from Africa to populate Eurasia, there must have been several dispersals, some of which did not result in permanent occupations,” said Eric Delson, a professor of anthropology at City University of New York, who was not involved in the Nature study.

This is still a preliminary study, however — a snapshot in time. This may be an isolated individual or part of an isolated community of adventurers. It’s not clear whether they left anything behind, or interbred with Neanderthals or other hominins. It’s an enigmatic find, but it’s one for which we lack the context to properly understand. Without more evidence, it’s hard to say where this population came from, how far it ranged, and for how long it survived.

The study has been published in Nature.

Early humans adapted to hunt monkeys and squirrels

An important part of what enabled humans to spread over such a large geographical range was our ability to adapt to different environments. As mankind spread from Africa to the rest of the world, it encountered a large variety of climates and environments. However, tropical forests were thought to be a barrier in this development, due to the absence of large animals that early humans could hunt. Now, archaeologists believe they’ve finally solved the puzzle.

Remote view of the cave. Image credits: Rapa123 / Wikipedia.

In a new study, scientists report that human populations were able to specialize in the hunting of small arboreal animals for tens of thousands of years. This is the oldest and longest record of sophisticated, active primate hunting by foragers.

The key to the study was the Fa-Hien Lena cave, the oldest archaeological site in Sri Lanka, surrounded by tropical forests. Researchers found sophisticated bones and tools, along with numerous remains from small mammals, including primates — essentially a smoking gun indicating that early humans specialized in the hunting of these animals. Dating techniques indicated that this went on from 45,000 to 3,000 years ago.

“The results demonstrate specialized, sophisticated hunting of semi-arboreal and arboreal monkey and squirrel populations from 45,000 years ago in a tropical rainforest environment,” says Oshan Wedage, lead author of the study, of the Max Planck Institute for the Science of Human History. Co-author Dr. Noel Amano, also of the Max Planck Institute for the Science of Human History, adds, “This was complemented by sophisticated bone tool technologies which were, in turn, created from the bones of hunted monkeys.”

Specializing in hunting these small mammals is no easy feat. They’re fast, nimble, and don’t provide a lot of calories, which the hunters would have required. Comparing a squirrel to something like a mammoth, you can easily understand just how many squirrels you need to eat to reach the same amounts of nutrients. This means that early humans needed to become active and very efficient in order to survive.

The new findings are a testament to the extreme resourcefulness and adaptability of early humans. Previously it was suggested that humans only hunted small game during periods of crisis (such as the Ice Age). This shows that populations were not only capable of hunting smaller creatures, but they managed to survive for many centuries with this way of life.

Researchers studied 14,500 bone fragments from Sri Lanka’s Fa Hien cave. Out of the animal remains, 70% belonged to tree squirrels and monkeys, indicating that this was the preferred prey of the local populations. Image credits: N. Amano / Nature Communications.

The team then took things one step further, and looked at things from the animals’ perspective. Specifically, they wanted to see if such an extended period of human hunt took a tool on the species. Judging by the assemblage they analyzed, they conclude that the population wasn’t heavily affected, and the humans were essentially a sustainable part of the ecosystem.

They were careful resource managers, hunting more of the abundant small game, and rarely feasting on larger prey like deer or pigs.

“This ‘monkey menu’ was not a one-off, and the use of these difficult-to-catch resources is one more example of the behavioural and technological flexibility of H. sapiens,” says Prof. Michael Petraglia of the Max Planck Institute for the Science of Human History, a senior author of the study.

Now, the team is taking a closer look at the bone tools to figure out how they were used. Was it a bow-and-arrow, a spear, or some sort of ambush/trap? We don’t know for sure yet, but whatever it was, it was complex, elaborate, and allowed humans to thrive in an unfriendly environment.

dna

The Timeline of Human Evolution

dna

Credit: Pixabay.

Homo sapiens, as compared to other species, have had by far the greatest impact on the planet in the shortest amount of time. Today, we number over seven billion and have altered the environment around us so much that we’ve brought about a new geological era fashioned in our image the Anthropocene.

We’ve sent spacecraft close to the edge of the solar system, landed on the moon, written epic poems and literature, and split the atom. However, only a few thousand years ago, humans were widely dispersed around the world in compact and fragile tribes that were at the mercy of the elements.

Go back in time enough and you’ll find a population of Homo sapiens who were the ancestors of all humans living today. If you went even further, you’d find inflection points where our lineage met up with Neanderthals, then chimps, and eventually all primates, mammals, and the very first life forms.

What a ride! What’s really amazing, though, is how scientists can piece together this evolutionary history using only the tools at their disposal.

Let’s dive deep and take a look at some of the major events in the development of the human species, Homo sapiens, as well as the evolution of humanity’s ancestors.

Sahelanthropus tchadensis (6-7 million years ago)

Cast of a Sahelanthropus tchadensis skull (Toumaï). Credit: Wikimedia Commons.

Cast of a Sahelanthropus tchadensis skull (Toumaï). Credit: Wikimedia Commons.

Between 6 and 7 million years ago, in the forests and grasslands of West-Central Africa (today it’s the country of Chad) lived one of the oldest known species in our family tree. Discovered in 2001, and known only from a skull and teeth, Sahelanthropus is famous for being one of the first upright walkers — the trait that defines the hominin lineage.

Artist recreation of Sahelanthropus tchadensis by artist John Gurche, Trumansburg, NY. This species lived sometime between 7 and 6 million years ago in West-Central Africa (Chad). Credit: Wikimedia Commons.

Artist recreation of Sahelanthropus tchadensis by artist John Gurche, Trumansburg, NY. This species lived sometime between 7 and 6 million years ago in West-Central Africa (Chad). Credit: Wikimedia Commons.

The species had a combination of ape-like and human-like features. Its brain was small (slightly smaller than a chimp’s) with a sloppy face and prominent brow. However, it also possessed strikingly human-like features like small canine teeth and a spinal cord opening beneath the skull rather than towards the back (as encountered in non-bipedal apes).

Orrorin tugenensis (6 million years ago)

Also discovered in 2001, this time in the Tugen Hills region of central Kenya, Orrorin tugenensis is another prime example of early upright locomotion. It is the only species in the genus Orrorin.

More than a dozen fossils of this species have been excavated thus far, dating between about 6.2 million and 6.0 million years old. Its name means “original man in the Tugen region,” in the local language.

Orrorin tugenensis individuals were about the size of a chimpanzee and had small teeth lined with thick enamel, much like modern humans. Their most important body part was their upper femur, which had evidence of bone buildup typically seen in a biped’s. Scientists think Orrorin tugenensis climbed trees but were also capable of walking upright.

Ardipithecus kadabba (5.2-5.8 million years ago)

Credit: Alchetron.

Credit: Alchetron.

This early hominin is known in the fossil record by a few post-cranial bones and some teeth, but also hand, arm, and foot bones, as well as a clavicle. The bipedal Ardipithecus kadabba (‘kadabba’ means ‘oldest ancestor’ in the Afar language) was chimpanzee-like in body proportions and brain size, but had canines that resemble later hominins. We know it likely walked upright judging from the large toe that has a broad and robust appearance.

Its fossils were discovered in the Middle Awash region of Ethiopia in 1997. Judging from fossil animal evidence retrieved from the same site, these early human likely lived in a mixed habitat of woodlands and grasslands.

Ardipithecus ramidus (4.4 million years ago)

Ardipithecus ramidus specimen, nicknamed Ardi. Credit: Wikimedia Commons.

Ardipithecus ramidus specimen, nicknamed Ardi. Credit: Wikimedia Commons.

The earliest hominin with the most extensive evidence for bipedalism is the 4.4-million-year-old Ardipithecus ramidus. The first fossils of this species were discovered in 1994 but it was only in 2009, after extensive analysis, that researchers announced their results, introducing the world to a nearly complete skeleton nicknamed ‘Ardi’.  The species was named after ‘ramid’, which means ‘root’ in the Afar language of Ethiopia and refers to the closeness of this new species to the roots of humanity, while ‘Ardi’ means ‘ground’ or ‘floor’.

Ardi’s foot bones are comprised of a divergent large toe combined with a rigid foot, which indicates bipedal locomotion. The pelvis has features that suggest it was suited for both tree-climbing and upright walking. Scientists have argued that Ardipithecus ramidus is indicative of a human-African ape common ancestor that was not chimpanzee-like, in contrast to other hominins before it. There was little difference in size between males and females, judging from the sampled canine teeth.

Based on the faunal remains found alongside Ardi’s skeleton, she likely lived in a wooded environment. This is in direct violation of the ‘open savanna theory’ for the origin of bipedalism.

Australopithecus anamensis (3.9-4.2 million years ago)

Australopithecus anamensis fossils at display at the Royal Belgian Institute of Natural Sciences, Brussels. Credit: Wikimedia Commons.

Australopithecus anamensis fossils at display at the Royal Belgian Institute of Natural Sciences, Brussels. Credit: Wikimedia Commons.

Australopithecines are the first human ancestors to live in the savannah. Australopithecus anamensis has a combination of ape and human features, such as long forearms and adapted wrist bones indicative of tree-climbing along with a shin bone with an expanded area of bone and human-like orientation of the ankle joint. ‘Anam’ means ‘lake’ in the Turkana language spoken by the locals in Kanapoi in northern Kenya, where the first fossils were found.

Australopithecus afarensis (2.95-3.85 million years ago)

A. afarensis, forensic facial reconstruction. Credit: Wikimedia Commons.

A. afarensis, forensic facial reconstruction. Credit: Wikimedia Commons.

This species is one of our best-known ancestors due to a number of major discoveries, including a set of fossil footprints and a fairly complete fossil skeleton of a female nicknamed ‘Lucy’. She was nicknamed ‘Lucy’ after the song ‘Lucy in the Sky with Diamonds’ by The Beatles. More than 300 Australopithecus afarensis individuals have been discovered thus far in Ethiopia, Kenya, and Tanzania.

Like chimpanzees, A. afarensis children grew rapidly after birth and reached adulthood earlier than we modern humans do. However, this left individuals with less time for parental guidance and socialization during childhood.

Similar to other primitive hominins, A. afarensis had both ape and human-like features. Its face had ape-like proportions, featuring a flat nose and a strongly protruding lower jaw, and the braincase housed only 500 cubic centimeters of brain (just 1/3 the size of a modern human brain). Its long, strong arms with curved fingers were adapted for climbing trees. However, its small canine teeth were very human-like and its body stood on two legs. It seems like this double adaptation for living both in the trees and in the ground helped A. afarensis become a highly successful species, as it survived for almost a million years through changing climate and environments.

Besides fossils indicative of bipedal locomotion, scientists also discovered A. afarensis footprints in Tanzania, East Africa, dated to 3.6 million years ago. The quite human-like footprints were made by hominins that walked through a layer of ash burst that had settled on the ground after a distant volcano erupted. The footprints are of major significance as they are the first direct evidence (i.e. not fossil bones) that our ancestors were walking upright 3.6 million years ago.

Kenyanthropus platyops (3.2-3.5 million years ago)

Found in Kenya, the fossil is approx. 3,5 mil years old. Its brain size is 350cm³. This is a model of the skull as on display in the Brno museum of evolution named "Anthropos". Credit: Wikimedia Commons.

Found in Kenya, the fossil is approx. 3,5 mil years old. Its brain size is 350cm³. This is a model of the skull as on display in the Brno museum of evolution named “Anthropos”. Credit: Wikimedia Commons.

Not much is known about Kenyanthropus platyops, whose name means ‘flat face’. Kenyanthropus inhabited Africa at the same time as Lucy’s species Australopithecus afarensis and was a flat-faced (a human feature), small-brained, bipedal hominin.

The species remains an enigma: some claim it’s a bridge between the walking apes and modern humans, deserving an entirely new genus for itself, while others classify it as a separate species of Australopithecus Australopithecus platyops.

Australopithecus africanus (2.1-3.3 million years ago)

Credit: Wikimedia Commons.

Credit: Wikimedia Commons.

The Taung child, which was found in 1924, provided the first evidence that early humans inhabited Africa. Prof. Raymond Dart was the first to describe the species and named it Australopithecus africanus (meaning southern ape of Africa). He claimed the species was an intermediate between apes and humans but it took more than 20 years for the scientific community to widely accept Australopithecus as a member of the human family tree.

Australopithecus africanus was anatomically similar to A. afarensis, with a combination of human-like and ape-like features — another hominin that adapted to both climbing trees and walking upright. Its skull was bigger and housed a bigger brain than A. afarensis, however. It is also thought to be a direct ancestor of modern humans.

Paranthropus aethiopicus  (1.2-2.3 million years ago)

Paranthropus aethiopicus skull ("Black Skull") replica. Credit: Wikimedia Commons.

Paranthropus aethiopicus skull (“Black Skull”) replica. Credit: Wikimedia Commons.

Paranthropus aethiopicus was a species originally proposed in 1967 by a team of French paleontologists who analyzed an incomplete mandible. At the time, scientists thought it was too early to describe a new species based on such little evidence. However, in 1985, Alan Walker and Richard Leakey discovered the famous “Black Skull” west of Lake Turkana in Kenya, which validated that claim that we had found a new “robust” australopithecine species.

P. aethiopicus had a strongly protruding face, large teeth, a powerful jaw, and a well-developed sagittal crest on top of the skull, as well as huge chewing muscles — all adaptations that enabled this hominin to chew with a large force.

Paranthropus boisei (1.2-2.3 million years ago)

Paranthropus boisei reconstruction. Credit: Wikimedia Commons.

Paranthropus boisei reconstruction. Credit: Wikimedia Commons.

In 1959, Mary Leakey discovered the ‘Zinj’ skull, which became the type specimen for P. boisei. These early human fossils, unearthed from Olduvai Gorge in northern Tanzania, indicate large, flat cheek teeth and thick enamel. For this reason, the ‘Zinj’ skull is often nicknamed the ‘Nutcracker Man.’

The flaring cheekbones made P. boisei’s face appear very wide and dish-shape, allowing bigger jaw muscles to grow and support massive cheek teeth that were four times the size of modern human’s.

P. boisei is often described as the largest of the Paranthropus genus (robust australopithecines). The relatively small brain size of 550 cm3 is similar to that of Australopithecus afarensis and Australopithecus africanus. Males were larger than females, as is true of all australopithecine species, standing 1.37 and 1.24 meters tall respectively.

Homo habilis (1.4-2.33 million years ago)

Forensic reconstruction of Homo habilis, , exhibit in LWL-Museum für Archäologie, Herne, Germany. Credit: Wikimedia Commons.

Forensic reconstruction of Homo habilis exhibit in LWL-Museum für Archäologie, Herne, Germany. Credit: Wikimedia Commons.

Known as ‘Handy Man’, Homo habilis is a species of the genus Homo which lived during the Gelasian Pleistocene period. Mary and Louis Leakey discovered the hominin’s first fossils in Tanzania between 1962 and 1964.

Its appearance is the least similar to modern humans of all species in the genus. Homo habilis was short, standing only 3 ft 4 inches to 4 ft 5 inches (100 – 135 cm) in height. It had disproportionately long arms compared to modern humans, but it had a far less protruding face than australopithecines, from which scientists think it descended. Its cranial capacity was bigger than australopithecines but still rather smallonly half the size of modern humans.

The species was nicknamed ‘Handy Man’ due to the fact that the hominin is thought to have mastered the Lower Paleolithic Olduwan tool set which utilized stone flakes. Homo habilis is thought to be the ancestor of Homo ergaster, itself the ancestor of Homo erectus. It’s quite possible that Homo habilis is a direct ancestor of modern humans, but this is still a matter for debate among scholars.

Homo rudolfensis (1.8-1.9 million years ago)

Homo rudolfensis skull (KNM ER 1470) reconstruction displayed at Museum of Man, San Diego. Credit: Wikimedia Commons.

Homo rudolfensis skull (KNM ER 1470) reconstruction displayed at Museum of Man, San Diego. Credit: Wikimedia Commons.

Richard Leakey’s team uncovered Homo rudolfensis fossils near the shores of Lake Rudolf (now known as Lake Turkana) in 1972, and it was named by Russian scientist V.P. Alexeev in 1986. Only one really good fossil of H. rudolfensis has ever been found and, initially, scientists thought it belonged to H. habilis. With a braincase size of 775cm3, H. rudolfensis had a considerably larger brain case than H. habilis.  In any event, Homo rudolfensis was contemporary with Homo habilis and the two likely interacted.

Homo ergaster (1.3-1.8 million years ago)

Homo ergaster skull reconstruction of the Turkana Boy/Nariokotome Boy from Lake Turkana, Kenya. Museum of Man, San Diego. Credit: Wikimedia Commons.

Homo ergaster skull reconstruction of the Turkana Boy/Nariokotome Boy from Lake Turkana, Kenya. Museum of Man, San Diego. Credit: Wikimedia Commons.

This is one of the earliest species of the Homo genus that lived in eastern and southern Africa during the early Pleistocene. Homo ergaster means ‘workman’ — a name given to the hominin for its advanced lithic technology.

Hand axes found at Saint-Acheul in France that are thought to have been shaped by H. ergaster indicate that the hominin manufactured tools similar to early humans during the Lower Palaeolithic era. The technology, characterized by oval and pear-shaped bifacial hand axes and called the Acheulean industry, was the dominant form of tools for the vast majority of humans.

Remarkably, some argue that Homo ergaster may have been the first hominin to use a ‘human’ voice and a proto-language. There is no archaeological evidence to suggest this, but the species’ cervical vertebrae, well-evolved brain, and other physical capabilities suggest it may have had the necessary biological machinery for voicing words and using symbolic thought, such as figurative art.

While its ancestry is still debated, Homo ergaster is thought to be the direct ancestor of later hominins such as Homo heidelbergensis, Homo sapiens, and Homo neanderthalensis, as well as Asian Homo erectus.

Homo erectus (200,000-1.89 million years ago)

Forensic reconstruction of an adult female Homo erectus. Credit: Wikimedia Commons.

Forensic reconstruction of an adult female Homo erectus. Credit: Wikimedia Commons.

Early hominins were capable of upright walking but they didn’t exactly get around as we do today, as indicated by their adaptation for tree climbing. They still retained primitive features, such as long, curved fingers and toes, as well as longer arms and shorter legs — that is, until H. erectus (meaning ‘upright man’) came into the picture about 1.89 million years ago. During this time, the climate in Africa turned drier, facilitating open environments suited for walking.

Homo erectus had little body hair, so it was able to shed heat and be active throughout the day. The appearance of the vestibulocochlear apparatus — an organ of balance and movement change present in modern humans — allowed H. erectus to see distant targets well. These adaptations may have heralded a change from scavenger to hunter in our species’ lineage. This is further evidenced by the hominin’s smaller gut and teeth relative to its predecessors, which suggest it had a better diet. Bone protein released during fire suggest that H. erectus also knew how to make fire or, at least, how to exploit when necessary.

This is hominin grew tall and had long legs, making it a completely terrestrial creature.  It may have used a proto-language, as indicated by the vertebrae fossils of Homo erectus georgicus, a sub-species of Homo erectus.

Homo heidelbergensis (200,000-700,000 years ago)

A reconstruction of Homo heidelbergensis in Atapuerca. Credit: Wikimedia Commons.

A reconstruction of Homo heidelbergensis in Atapuerca. Credit: Wikimedia Commons.

Homo heidelbergensis was a sophisticated hunter and tool maker. The hominin was relatively tall — 163.6 cm on average — and had a larger average brain capacity than modern humans.

Fire-altered tools and burnt wood at the site of Gesher Benot Ya-aqov in Israel suggests that H. heidelbergensis was capable of controlling fire by building hearths (early fireplaces) by 790,000 years ago.

H. heidelbergensis was also the first hunter of large game animals; remains of animals such as wild deer, horses, elephants, hippos, and rhinos with butchery marks on their bones have been found together at sites with H. heidelbergensis fossils.

With regards to its social behavior, H. heidelbergensis may have been the first species of early humans to bury their dead. The species also likely practiced personal adornment, as indicated by the discovery of red ochre at Terra Amata, and quite possibly utilized a proto-language.

Homo neanderthalensis probably diverged from Homo heidelbergensis roughly 300,000 years ago in Europe; Homo sapiens probably diverged between 100,000 and 200,000 years ago in Africa.

Homo rhodesiensis (125,000-400,000 years ago)

"Broken Hill Skull" from Kabwe, Zambia (replica, Museum Mauer, near Heidelberg, Germany). Credit: Wikimedia Commons.

“Broken Hill Skull” from Kabwe, Zambia (replica, Museum Mauer, near Heidelberg, Germany). Credit: Wikimedia Commons.

Homo rhodesiensis was robust, with very large brow ridges and a broad face. For this reason, it is sometimes referred to as the ‘African Neanderthal’, although the title might be a bit too much. Nowadays, anthropologists consider that H. rhodesiensis has intermediate features between Homo sapiens and Homo neanderthalensis.

Some argue it is the ancestor of Homo sapiens idaltu, which itself was the ancestor of Homo sapiens sapiens, our species.

The ‘Rhodesian man’ fossil skull was discovered at Broken Hill in Northern Rhodesia, now Zambia, by Tom Zwiglaar in 1921.

Homo neanderthalensis (40,000-400,000 years ago)

Credit: Flickr, Ryan Somma.

Credit: Flickr, Ryan Somma.

The Neanderthals are our closest extinct human relatives.

In 1829 at Engis, Belgium, and in 1848 at Forbes Quarry, Gibraltar, scientists excavated Neanderthal fossils — the first early human fossils ever found.

The name ‘Neanderthal’ was chosen because of the location of the first confirmed specimen of the species — in the Feldhofer Cave of the Neander Valley in Germany. Tal, or thal, means “valley” in German. The fossils in Belgium and Gibraltar weren’t initially recognized at the time of their discovery.

Neanderthals were shorter but bulkier than modern humans. Defining features include a protruding brow ridge and angled cheekbones.

The Neanderthals adapted to cold climates, having a big nose that was good at humidifying and warming the cold, dry air.

There’s this myth of the neanderthal brute, but recent evidence suggests our long-lost relatives weren’t all that different from us. Their brains were just as large, if not bigger, than ours. Archaeological evidence suggests they were skilled hunters and craftsmen who knew how to control fires and raise shelters. They made and used clothing and fashioned symbolic and ornamental objects.

They also buried their dead and, occasionally, marked graves with ornaments, such as flowers. This sort of behavior has never been practiced by another primate or early human species that we know of.

Scientists have recovered and sequenced the DNA from over a dozen Neanderthal individuals as part of the Neanderthal Genome Project. We now know that non-African modern humans alive today share as much as 4% of their DNA with Neanderthals — the byproduct of ancient inter-breeding.

We don’t know for sure what killed the Neanderthals off. It might have been competition with Homo sapiens, climate change, or both. Neanderthals were a successful species and they were likely as smart as humans — but they were still fragile enough to get wiped out, which should get all of us thinking. At the end of the day, we all carry a bit of Neanderthal with us.

Denisova hominin (765,000-48,000 years ago)

A molar that belonged to an ancient Denisovan. Credit: Max Planck Institute for Evolutionary Anthropology.

Besides Neanderthals, anatomically modern humans co-existed with a third species of Homo called Denisovans.  The Denisovans occupied a vast realm stretching from the chill expanse of Siberia to the steamy tropical forests of Indonesia, suggesting that the third human of the Pleistocene was quite adaptable.

The species was first identified in March 2010 when scientists found a finger bone fragment of a juvenile female in the remote Denisova cave in the Altai mountains of Siberia. Analysis of the mtDNA of the finger bone showed it to be genetically distinct from the mtDNAs of Neanderthals and modern humans. However, subsequent studies suggest that the Denisovans shared a common origin with Neanderthals around 1 million years ago.

The conclusions of both the excavations and sequencings are up for debate since the Denisova Cave has been occupied by all three human forms.

Interestingly, up to 6% of the DNA of Melanesians and Australian Aborigines comes from Denisovans.

Homo floresiensis (???-50,000 years ago)

Reconstruction of female Homo floresiensis. Credit: Wikimedia Commons.

Reconstruction of female Homo floresiensis. Credit: Wikimedia Commons.

Homo floresiensis is a possible species in the genus Homo, which may have lived up to as early as 13,000 years ago.

In 2003, the partial skeletons of nine individuals were recovered from the Liang Bua Cave on the island of Flores in Indonesia. Stone tools made by this species that were found in the same cave date to between 50,000 and 190,000 years old.

This tentative species of Homo is also called the ‘Hobbit’ due to the hominin’s small body and brain. These individuals were 3 feet 6 inches (1 meter) tall and had large teeth for their small size, shrugged-forward shoulders, no chins, receding foreheads, and relatively large feet due to their short legs.

Scientists think that H. floresiensis’ diminutive stature and minuscule brain are the result of island dwarfism — an evolutionary process where long-term isolation on a small island with limited resources and lack of predators causes organisms to grow small in size. Pygmy elephants on Flores, now extinct, showed the same adaptation.

Homo sapiens (300,000 years ago-present; you are here!)

Credit: Pixabay.

It is largely believed that during a time of dramatic climate change 300,000 years ago, Homo sapiens evolved in Africa. That’s us!

Modern humans are characterized by a lighter skeletal build than earlier human species. One of the most defining traits of the species is the very large brain, which varies in size depending on population and sex, but on average is approximately 1,300 cubic centimeters. To house such a big brain, humans have had to reorganize the skull, which is now thin-walled and high vaulted with a flat and near vertical forehead. This is in stark contrast to the heavy brow ridges and prognathism of earlier species of Homo. Our jaws are also less heavily developed and contain smaller teeth.

An analysis of mitochondrial DNA has demonstrated that the greatest level of genetic diversity in modern humans occurs within the African continent, represented by the mtDNA macro-haplogroup L. This points to the fact that our species originated in Africa.

According to a 2017 study published in Naturethe oldest modern human specimen was found in an unlikely place: Morocco. The skull, face and jaw bones were identified at an archaeological site near the Atlantic coast and dated to 315,000 years ago. Previously, most researchers had placed the origins of our species in East Africa about 200,000 years ago.

“Until now, the common wisdom was that our species emerged probably rather quickly somewhere in a ‘Garden of Eden’ that was located most likely in sub-Saharan Africa,” Jean-Jacques Hublin, an author of the study and a director at the Max Planck Institute for Evolutionary Anthropology in Leipzig, told Nature. Now, “I would say the Garden of Eden in Africa is probably Africa — and it’s a big, big garden.”

For years, the prevailing narrative was that our species emerged in some isolated location in Africa, then expanded towards Europe and Africa through the Middle East in one great ‘Out of Africa’ migration. Now, scientists argue that the actual story of human dispersal if far more complex than this simplified narrative. Yes, humans originated in Africa, but according to the theory of “African multiregionalism,” they didn’t appear in one single place; rather, the cradle of humankind was the entirety of Africa. This may sound like a difficult concept to grasp because we’re so used to the conceptual framework of family trees, but as Ed Young eloquently puts it:

“The best metaphor for this isn’t a tree. It’s a braided river—a group of streams that are all part of the same system, but that weave into and out of each other.”

“These streams eventually merge into the same big channel, but it takes time—hundreds of thousands of years. For most of our history, any one group of Homo sapiens had just some of the full constellation of features that we use to define ourselves.”

The original ‘Out of Africa’ theory states that early Homo sapiens ancestors dispersed around the world by leaving an African hotspot 60,000 years ago. But in the past fifteen years, a great deal of archaeological and paleontological evidence, as well as genetic findings, have placed this hypothesis into question. Homo sapiens fossils dated between 70,000 to 120,000 years old were discovered in China and southeast Asia, and some even as far as Australia dated to 60,000 years ago. Human fossils found in the Skhul and Qafzeh caves in Israel that predate the Out of Africa timeframe are also worthy examples. If humans had barely begun to exit Africa 60,000 years ago, how can we explain these other findings?

Various migratory pathways associated with modern humans dispersing across Asia during the Late Pleistocene. Credit: Bae et al. 2017.

The most plausible explanation is that humans indeed embarked on a massive wave of migration around that time, possibly spurred by a changing climate. However, before this truly massive undertaking, early hunter-gatherers must have migrated in smaller waves.

“The initial dispersals out of Africa prior to 60,000 years ago were likely by small groups of foragers, and at least some of these early dispersals left low-level genetic traces in modern human populations. A later, major ‘Out of Africa’ event most likely occurred around 60,000 years ago or thereafter,” explains Michael Petraglia of the Max Planck Institute for the Science of Human History in a statement. 

We’re still pretty far away from unraveling all of the evolutionary twists and turns that eventually led us to where we’re at now: this strange species the likes of which the world has never seen, which is capable of so much beauty, but also equally intense moments of stupidity. But science is always full of surprises. What would be interesting is having a glimpse into the next step in our genus’ evolution. Will this new species of Homo replace Homo sapiens, like we probably did with the Neanderthals? What will it look like and will techniques like CRISPR capable of modifying genes with surgical precision play a role in its developments? All worthy things to consider. Please, leave your opinions in the comments.

: Fossil finger bone of Homo sapiens from the Al Wusta site, Saudi Arabia. Credit: Ian Cartwright

Ancient human fossil finger found in Arabia could rewrite our species’ history

: Fossil finger bone of Homo sapiens from the Al Wusta site, Saudi Arabia. Credit: Ian Cartwright

: Fossil finger bone of Homo sapiens from the Al Wusta site, Saudi Arabia. Credit: Ian Cartwright

A fossilized 90,000-year-old finger unearthed in Arabia is the earliest evidence of Homo Sapiens presence outside Africa and the Levant. Although today the region where the fossil was found is dry and rather inhospitable, the climate there used to be humid and monsoonal at the time the human the finger belonged to was still alive. As such, the findings suggest that not only were early humans more geographically dispersed than we used to think, they were also successfully adapting to new environments — a huge step forward in our species’ quest for global domination.

“The Arabian Peninsula has long been considered to be far from the main stage of human evolution. This discovery firmly puts Arabia on the map as a key region for understanding our origins and expansion to the rest of the world. As fieldwork carries on, we continue to make remarkable discoveries in Saudi Arabia,” said Professor Michael Petraglia of the Max Planck Institute for the Science of Human History.

The team of international researchers led by the Max Planck Institute for the Science of Human History was conducting archaeological fieldwork in the Nefud Desert of Saudi Arabia when they came across the striking fossil. The site of Al Wusta where the researchers set camp used to house a freshwater lake, which attracted all sorts of creatures from hippopotamuses to tiny freshwater snails. Among the many animal fossils and human tools, the researchers also found a 3.2-cm-long fossil, which was immediately recognized as a human finger bone.

In order to properly identify the finger bone, researchers scanned it in 3-D then compared it to various other finger bones like recent modern humans, Neanderthals, but also species of primates. The analysis confirmed that the fossil belonged to an early human, marking the first ancient human fossil found in Arabia.

The age of the fossil was dated using a technique called uranium series dating, which involves etching microscopic holes in the fossil with a laser and measuring the ratio between tiny traces of radioactive elements. By this method, the researchers estimate the fossil is around 88,000 years old. Dates obtained from other animal fossils and sediments at the Al Wusta site converged to about the same age, approximately 90,000 years ago.

General view of the excavations at the Al Wusta site, Saudi Arabia. The ancient lake bed (in white) is surrounded by sand dunes of the Nefud Desert. Credit: Michael Petraglia

General view of the excavations at the Al Wusta site, Saudi Arabia. The ancient lakebed (in white) is surrounded by sand dunes of the Nefud Desert. Credit: Michael Petraglia

Although tiny and seemingly insignificant, this finger fossil might be an important piece of the complex jigsaw puzzle that is the story of human dispersal out of Africa. Traditionally, the expansion of our species out of the African continent is thought to have occurred in at least two phases. One early dispersal followed the Levantine corridor, alongside the eastern portion o the Mediterranean Basin. Findings in the Misliya Cave, Israel, suggest this dispersal occurred as early as 177,000 years ago. The second phase of modern human dispersal out of Africa is thought to have taken place as early as 65,000 years ago, partially overlapping with the Neanderthals’ presence in the Levant, which stretched from about 70,000 to 48,000 years ago. Oddly enough, researchers have identified fewer human fossils in this second phase than in the much earlier first phase. Instead, scientists studying the second phase have had to mostly rely on stone artifacts associations, chronometry, and other indirect evidence.

Where does the Al Wasta finger bone fit into all of this? Its age suggests that H. sapiens occupied areas outside of Africa and the Levant at a time between phase 1 (177,00-133,000 years ago) and the later phase 2 (~65,000 years ago). This supports the argument that there were never two different phases of dispersal, and instead African groups have diffused continuously across the Levantine-Arabian nexus to Eurasia as early as 177,000 years ago. What’s more, Al Wusta stone tools differ in detail and assemblage from the Levantine variety recovered from both early and late migrations.

“This discovery for the first time conclusively shows that early members of our species colonized an expansive region of southwest Asia and were not just restricted to the Levant. The ability of these early people to widely colonize this region casts doubt on long-held views that early dispersals out of Africa were localized and unsuccessful,” said lead author Dr. Huw Groucutt, of the University of Oxford and the Max Planck Institute for the Science of Human History.

The findings appeared in the journal Nature Ecology & Evolution.

Credit: Wikimedia Commons.

Scientists double the number of Neanderthal genomes, gleaning new tribal insights

Credit: Wikimedia Commons.

Credit: Wikimedia Commons.

After scientists sequenced the first Neanderthal genome, we were surprised to learn that our extinct cousins actually interbred with modern humans. It’s believed all non-Subsaharan individuals alive today carry about 2% Neanderthal DNA. But our Neanderthal ancestry might be even richer than we thought: five new Neanderthal genomes sourced from Belgium, France, Croatia, and Russia have been recently sequenced. This effectively doubles the number of genomes available.

The samples were taken from bones and teeth, ground into a fine powder, and treated with a mild hypochlorite solution to remove any contaminants. All the new genomes are 39,000 to 47,000 years old, which makes them latecomers in the species’ history.

“Our work demonstrates that the generation of genome sequences from a large number of archaic human individuals is now technically feasible, and opens the possibility to study Neandertal populations across their temporal and geographical range”, says Janet Kelso, the senior author of the new study.

After the researchers at the Max Planck Institute for Evolutionary Anthropology analyzed the five Neanderthals, they compared them to previously sequenced Neanderthals (whole-genome sequencing was available for only four Neanderthal individuals prior to this study), but also a Denisovan, and samples from our own species.

Upper molar of a male Neandertal from Spy, Belgium.Credit: I. Crevecoeur.

Upper molar of a male Neandertal from Spy, Belgium.Credit: I. Crevecoeur.

They found that the five individuals shared a common ancestor about 150,000 years ago with another Neanderthal individual whose remains were recovered from a Siberian cave. According to the researchers, they can now identify 10 to 20 percent more Neanderthal DNA in people living today than it was possible when everything scientists had at their disposal was the Altai Neanderthal genome, the first Neanderthal genome to be sequenced.

Very curiously, none of these individuals had any modern human DNA contained their genomes, despite having shared the same timeline. This suggests that the gene flow may have been strictly unidirectional — from Neanderthals to humans, but not the other way around. It’s not clear whether the gene flow comes from male or female Neanderthals, so there are still open questions concerning the intimate dynamic between the two species.

It also seems that these late Neanderthals were more related to the Neanderthals that mated with the ancestors of modern-day Europeans and Asians than the older Neanderthal populations found in Siberia.

For thousands of years, the Mezmaiskaya Cave, laying near the border between Russia and Georgia in the Caucasus mountains, had offered Neanderthals shelter. The newly extracted genetic information allowed the researchers to compare two individuals who had lived approximately 20,000 years apart. To the researchers’ surprise, the two individuals were not closely related.

Instead of both being distantly related to Western European Neanderthals, the team found that the younger Neanderthal was more genetically similar to Croatian, Belgian, and French Neanderthals than to the older Neanderthal found at the cave. This suggests that the more recent individual was part of a new population that replaced the former ones, which were likely wiped out. The authors believed that “extreme cold periods in northern Europe may have triggered the local extinction of Neanderthal populations.” Eventually this population, too, collapsed with the extinction of its own species — only to be replaced by our own.

“We see that the genetic similarity between these Neandertals is well-correlated with their geographical location. By comparing these genomes to the genome of an older Neandertal from the Caucasus we show that Neandertal populations seem to have moved and replaced each other towards the end of their history”, says first author, Mateja Hajdinjak.

The findings appeared in the journal Nature.

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.

Upper jaw bone with intact teeth, dated as being between 177,000 and 194,000 years old. Credit: Rolf Quam.

Oldest human fossil outside Africa suggests our species left the continent 100,000 years earlier than thought

Our species first evolved in Africa and then dispersed to Europe and Asia not in one massive exodus, but likely in multiple waves of migration over the last 200,000 years. Multiple lines of evidence collected in the past decade support this idea, the most recent of which being reported by researchers at Tel Aviv University who described a 200,000-year-old jawbone discovered in an Israeli cave. The jawbone is twice as old as any Homo sapiens fossil discovered outside of Africa.

Upper jaw bone with intact teeth, dated as being between 177,000 and 194,000 years old. Credit: Rolf Quam.

Upper jaw bone with intact teeth, dated as being between 177,000 and 194,000 years old. Credit: Rolf Quam.

The well-preserved upper jawbone containing eight intact teeth was found in the Misliya cave. Although the teeth are rather large compared to those of a modern human, researchers say the fossil undoubtedly belongs to a Homo sapiens, as reported in the journal Science. 

Along with the jawbone, excavations revealed stone tools and blades, which were fashioned by the cave’s crafty inhabitants to hunt and butcher gazelles, wild boars, turtles, and ostrich. Even pieces of an ancient matting made from plants that Misliya dwellers used to sleep on was found amongst the artifacts and fossils.

Radiocarbon analysis of both the fossil and tools suggests these are between 177,000 and 194,000 years old.

Up until recently, scientists used to think humans left Africa for Euroasia barely 60,000 years ago, where they quickly outclassed contemporary relatives like Neanderthals and Denisovans. But the evidence from recent years puts this singular ‘Out of Africa’ theory into question. For instance, there’s a trove of 100,000-year-old human teeth found in a cave in China, thousands of miles away from humanity’s cradle in Africa. Other similar findings were made in southeast Asia and even as far as Australia dated to 60,000 years ago. If humans had barely begun to exit Africa 60,000 years ago, how can we explain these other findings?

Now, Misliya breaks the mold of the classical theory when Homo sapiens first left Africa, suggesting that humans left the continent whenever the climate allowed it — or, conversely, when the climate forced them out. Prof. Israel Hershkovitz, who led the work at Tel Aviv University, thinks that humans came in and out of Africa frequently over the last couple hundred thousand years. The Misliya cave and others like it in present-day Israel were like “train stations” that exploring humans used on their way through Europe and Asia.

After settling Europe, modern humans out-competed Neanderthals into extinction, but not before interbreeding with them 50,000 years ago. To this day, all non-sub-Saharan humans carry 1-4 percent Neanderthal DNA. However, a recent DNA analysis of a Neanderthal leg bone discovered in a German cave suggests that interbreeding between the two species could have occurred as early as 200,000 years ago. Such a finding, peculiar as it seemed at first, now makes sense in light of the ancient Misliya jawbone.

It’s exciting to hear about such early excursions of our ancestors. Those must have been truly exciting times, but also very frightening and dangerous.

Our genes don’t lie, and according to population genetics studies, most modern-day populations outside Africa can trace their roots to a group that dispersed around 60,000 ago. It follows that earlier groups contributed very little, if anything, to our current lineage — most likely because they could not survive — to be fair, the odds weren’t really in their favor. It’s amazing, though, that after all this time, we can still piece together some of the long-lost history of our species’ most epic journey.

Sungir reconstruction 1.

Virtual reconstruction shows what the first modern humans to reach Europe looked like

A new computer animation, created using actual specimens and scientifically-accurate reconstruction methods, shows how some of the earliest Homo sapiens of Europe looked like.

Sungir reconstruction 1.

Something like this.
VR animation by Visual Science.

When Homo sapiens left Africa and migrated to other continents, they ran into other human species that had come to these lands previously. In certain cases, such as happened with the Neanderthals in Europe, the two groups got very friendly and now, well, now Europeans have 2% Neanderthal genes in their DNA.

So how did the original, un-interbred H. sapiens looked like? Well, thanks to Russian visualization studio Visual Science and the Institute of Ethnology and Anthropology of the Russian Academy of Science, we now have a pretty good idea.

The studio started from the skulls of boy and girl, the first estimated to be about 13 years old, while the girl (believed to be his sister) was likely 2-3 years younger, at the time of death. Their remains, which mark one of the earliest records of modern humans in Europe, were discovered in 1955 near present-day Sungir, Russia, a site which 28,000 to 32,000 years ago served as a settlement for H. sapiens — likely a seasonal hunting camp.

First, Visual Science laser-scanned and took high-definition pictures of the skulls, which were fed into a 3D-modeling program. This software was built following skull-based facial reconstruction techniques developed by Mikhail Gerasimov, a proeminent Soviet archaeologist and anthropologist. It’s still in use in Russia, Europe, and the United States, and in recent years the Gerasimov method has become even simpler and more accurate, thanks to ultrasound scanning and computer tomography.

Sungir reconstruction process.

VR animation by Visual Science.

Sergey Vasilyev, head of the physical anthropology department at the Institute of Ethnology and Anthropology gave the International Business Times some more details on the methods used:

“The anatomical and radiographic research methods used by Gerasimov allowed scientists to not only determine standards for the thickness of soft tissues along the face profile line, but also to reveal patterns in the distribution of the soft tissues’ thickness, depending on skull surface morphology development,” he told IBT.

“The structure of particular facial elements was determined by individual morphological features of the skull. Gerasimov’s successors developed techniques to restore the nose and ears. The degree of reconstruction authenticity was determined by a number of facial reconstruction projects that used the skulls of modern people, whose lifetime portraits were available. The methodology was tested mainly on forensic material.”

VR animation by Visual Science.

Despite likely being the ancestors of northern and eastern Europeans today, the two children don’t look quite like modern humans. This lack of similarity comes down to evolution — “modern” facial features are believed to have evolved after the stone age, as food processing and cooking allowed our jaws to become smaller and our overall facial anatomy followed suit.

Alongside the bodies, archaeologists also unearthed a large trove of cultural artifacts and ancient household items such as clothing, jewelry, and beads. With them, the studio could also clothe the two children in full (and quite spectacular) garb.

Neanderthal cave painting

Neanderthal and modern humans shared long childhoods

The rare discovery of a Neanderthal boy’s partial skeleton suggests he had similar growth patterns to those seen in modern humans. It’s yet another sign that the two species from the same Homo genus were very similar to one another.

Neanderthal cave painting

Credit: Wikimedia Commons.

The remains of the seven-year-old boy called El Sidron J1 are 49,000 years old. They were unearthed at the El Sidron archaeological site in Spain, a famous middle Paleolithic karst cave which has time and time again revealed insights into the lives of Neanderthals. Previously, bones retrieved from the site indicated Neanderthals engaged in cannibalism.

At the same cave, which stretches for approximately 3,700 meters (2.5 miles), with a central hall of approximately 200 m (650 feet), archaeologists have found over 400 lithic artifacts fashioned by Neanderthals. These include side scrapers, denticulates, hand axes, as well as several Levallois points, all made from local sources, mostly chert, silex, and quartzite.

More of the same

Spanish researchers working with the Paleoanthropology Group at Museo Nacional de Ciencias Naturales report the small Neanderthal boy was still evidently growing when he died. His brain was about 87.5% the size of that of an average adult Neanderthal. By the same age, a modern human boy should have a brain that’s 95% the size of an adult.

The boy’s vertebrae hadn’t yet fused, bone analysis showed. In modern human boys, the same bones typically fuse between age four to six. Limb bones, however, matured at the same rate as human boys, the authors reported in the journal Science. 

It might be possible that Neanderthal children enjoyed a longer childhood but it’s far too early to draw such a conclusion. We only have one such specimen, even that made of just 36% of his left side and parts of his skull.

The partial skeleton of a Neandertal boy he grew slowly, akin to modern human children. Credit: Paleoanthropology Group MNCNCSIC.

The partial skeleton of a Neandertal boy he grew slowly, akin to modern human children. Credit: Paleoanthropology Group MNCNCSIC.

Despite these dissimilarities, Neanderthal and modern human growth patterns are strikingly similar. In fact, it’s rather surprising that the differences are so subtle considering the two species didn’t evolve side by side. After splitting from a common ancestor during the Middle Pleistocene, Neanderthals evolved separately in western Eurasia while humans emerged from Africa.

The boy has been described by researchers as ‘sturdy’, having weighed 26 kilograms at his time of death and standing just over one meter (three and a half feet) tall. The cause of death is unknown though some cut marks on the bones could indicate cannibalism.

The findings cement a growing body of evidence that suggests Neanderthals and modern humans were strikingly similar. Neanderthals practiced rituals, made art, and buried their dead. Artifacts found in such places like El Sidron show that Neanderthals were at least as equally technologically proficient in stone tools as humans.

What’s more, they used manganese dioxide, today commonly found in batteries, to light fires some 50,000 years ago. Another recent study published just earlier this month showed that Neanderthals knew how to manufacture tar a good 200,000 years earlier than modern humans. And, lastly, the most important evidence of Neanderthal and Homo sapiens kinship can be found in almost every living, breathing human on the planet. Most Europeans and Asians have between 1 to 2 percent Neanderthal DNA, remnants from the time the two species interbred.

Neanderthals thrived in Europe from 240,000 to 30,000 years ago, until they abruptly disappeared. It’s thought that a combination of climate change and competition for food with humans wiped them off. Meanwhile, humans have not only risen to the top of the food chain — they’ve also mastered technology that can literally make us shoot for the moon. With this in mind, it’s tempting to consider ourselves as a superior master race. Personally, I can only reflect on a time when there were two Homo species sharing the same planet, until some fluke of fate destroyed one of them. We don’t know for sure what, but who’s to say it couldn’t have been the other way around? A world ruled by Neanderthals, and not us. Now, that would be an interesting place to visit.

Mammoth Chunks.

Modern humans might’ve killed off the Neanderthals by eating all the mammoth

The diets of early modern humans weren’t as diverse as previously believed, researchers from the Senckenberg Research Institute and Natural History Museum. In fact, they shared much of the menu with earlier Neanderthal populations — and competition for food might be what eventually drove these earlier human species extinct.

Mammoth Chunks.

Image via Todayilearned.

The first modern humans (Homo sapiens sapiens) are believed to have reached Europe some 43,000 years ago. They weren’t the first ones here, however. So they spent some 3,000 years or so steadily displacing and/or dating the local Neanderthals into extinction.

A big part of why they were able to do so is believed to come down to chow: modern humans, the theory goes, had much more varied diets. They’d eat stuff like fish and other seafood, for example, while the locals didn’t. Over time, this wider range of food gave them greater food security, more resilience to changes in flora and fauna, and greater access to nutrients and energy — so they could outbreed the Neanderthals, populate areas these couldn’t find enough food in, and gradually displaced them by relying on their greater adaptability.

“Many studies examine the question of what led to this displacement — one hypothesis postulates that the diet of the anatomically modern humans was more diverse and flexible and often included fish,” says paper co-author Prof. Dr. Hervé Bocherens of the Senckenberg Center for Human Evolution and Palaeoenvironment (HEP) at the University of Tübingen.

But that may not have been the case, an international team led by researchers from the Senckenberg Research Institute and Natural History Museum in Frankfurt, Germany, reports. Their work suggests that modern humans’ diets weren’t more flexible than that of Neanderthals. Just like them, early Homo sapiens diets revolved around mammoth meat and plants, the team finding no evidence for fish consumption. If the two human species’ diets overlapped as much as the research suggests, it’s likely we didn’t out-adapt Neanderthals — we simply out-ate them into extinction.

The Chowdown

To see if this theory holds water, the team studied the oldest known modern man fossils, recovered from the Buran Kaya caves on the Crimean Peninsula in the Ukraine. They were looking for chemical fingerprints left over from the stuff these populations ate, trying to piece together what early sapiens populations would have on the menu.

Buran Kaya.

Image credits Dorothée G. Drucker et al., 2017.

“In the course of this study, we examined the finds of early humans in the context of the local fauna,” explains Dr. Dorothée Drucker, co-author and biogeologist from Tübingen University. “Until now, all analyses of the diet of early modern humans were based on isolated discoveries; therefore, they are very difficult to interpret.”

To reconstruct the ancient dinner tables, the team measured the percentages of stable carbon and nitrogen isotopes (same chemical element but with extra neutrons, making them heavier and distinguishable) in the bones of ancient humans and animals they might’ve hunted — such as antelopes (Saiga tatarica), red deer (Cervus elaphus), horse (Equus sp), hare (Lepus sp), and mammoth (Mammuthus primigenius). Furthermore, as “all the selected specimens provided well-preserved collagen” the team looked at the nitrogen-15 content in this amino acid to allow them to trace the origin and proportion of nitrogen isotopes in the food.

The team reports that early modern humans incorporated a lot of plants in their diets, and they represented a significantly higher percentage of their overall food intake compared to Neanderthals. On the other hand, mammoths seem to have been the mainstay source of meat for both species, putting them in direct competition for food.

“Our results reveal a very high proportion of the nitrogen isotope 15N in early modern humans,” Bocherens adds. “However, contrary to our previous assumptions, these do not originate from the consumption of fish products, but primarily from mammoths.”

“Fish remains are missing in the site despite systematic sieving of the sediment during the excavations,” the paper notes.

In the end, this competition might have ended well for the Neanderthals. But it did for us so yay to that!

The paper “Isotopic analyses suggest mammoth and plant in the diet of the oldest anatomically modern humans from far southeast Europe” has been published in the journal Scientific Reports.

Virtual endocast of H. floresiensis (left) vs H. sapiens (right). Credit: rofessor Peter Brown, University of New England.

‘Hobbits’ didn’t evolve from a direct modern human ancestor. They likely originate from Africa instead

Until some 17,000 years ago, we humans shared the Earth with another close relative: Homo floresiensis. Often called the ‘hobbit’ because of its dwarfish stature, scientists have long debated the origin of this species first discovered as recently as 2003 in the Liang Bua cave on the remote Indonesian island of Flores. Now, scientists who embarked on the most comprehensive analysis of H. floresiensis yet claim the debate is over. The hominid is a distant relative to modern humans and, instead, likely evolved from another branch of hominid from Africa.

Homo Floresiensis skull. Credit: Stuart Hay - ANU.

Homo Floresiensis skull. Credit: Stuart Hay – ANU.

During the misty years following the discovery of the Flores hobbits, one of the most promising hypotheses explaining their origin posited that the 1.1-meter-tall creatures evolved from Homo erectus populations settled in Asia. Homo erectus is basically the first hominid that looked like a human.

Homo erectus had a long tenure. The earliest Homo erectus fossils are dated to roughly 1.8 million years ago, while the youngest fossils assigned to this species date to roughly 300 thousand years ago. The stature of Homo erectus is considered to be very similar to that of living humans having a hindlimb that’s much longer than in earlier forms. Its skulls were generally thicker and more massively built than those of H. sapiens, but all other features point to striking similarities between the two species.

Initial surveys of H. floresiensis remains suggested it was a direct descendant of H. erectus, but some critics have pointed out the evidence presented thus far is inconclusive. To get to the bottom of things Australian researchers led by Dr. Debbie Argue from the Australian National University examined 133 cranial, postcranial, mandibular, and dental remains coming from H. floresiensis but also other hominid species. No other study collected or examined these many samples before and previously scientists focused on finding the best match for the skull and lower jaw only.

A digital reconstruction of the face of H. floresis. Credit: ANU.

A digital reconstruction of the face of H. floresiensis. Credit: ANU.

The examination showed that H. floresiensis doesn’t share that as many features with H. erectus as some believed. Instead, the hobbits seem much more similar to Homo habilis, the earliest representative of the Homo genus which lived between 1.6 million and 2.4 million years ago.

“The analyses show that on the family tree, Homo floresiensis was likely a sister species of Homo habilis. It means these two shared a common ancestor,” Dr Argue said.

“It’s possible that Homo floresiensis evolved in Africa and migrated, or the common ancestor moved from Africa then evolved into Homo floresiensis somewhere.”

Virtual endocast of H. floresiensis (left) vs H. sapiens (right). Credit: rofessor Peter Brown, University of New England.

Virtual endocast of H. floresiensis (left) vs H. sapiens (right). Credit: rofessor Peter Brown, University of New England.

The findings refute the idea that the hobbits evolved from Asian Homo erectus which presumably underwent island dwarfing. Instead, a counter-hypothesis which suggests the hobbits evolved from an earlier ancestor in Africa, who was most likely Homo habilis, seems more favorable. The hobbits either evolved in Africa then migrated to Asia where they eventually reached the island of Flores in Indonesia or the common ancestor migrated from Africa then evolved into H. floresiensis somewhere on route or on the famous island itself.

The biggest takeaway is that H. floresiensis was far more primitive than previously thought, though it went extinct less than 15,000 years ago.

“We can be 99 per cent sure it’s not related to Homo erectus, and nearly 100 per cent chance it isn’t a malformed Homo sapiens,” said Professor Mike Lee of Flinders University and the South Australian Museum, and co-author of the study published in the Journal of Human Evolution.

The Aroeira skull discovered in Portugal that shares Neanderthal features. Credit: Javier Trueba.

Mysterious 400,000-year-old skull found in Portugal might have belonged to a Neanderthal ancestor

The Aroeira skull discovered in Portugal that shares Neanderthal features. Credit: Javier Trueba.

The Aroeira skull discovered in Portugal that shares Neanderthal features. Credit: Javier Trueba.

About half a million years ago, our ancestors from the genus Homo began to expand their reach out of Africa and into Europe and Asia through the Middle East. Some of these hominids would ultimately evolve into Neanderthals, which lived from 200,000 up to 40,000 years ago, but it was never clear who was their direct ancestor. A fantastic anthropological find might help settle this long-standing debate. Buried deep in rock-solid sediments, researchers uncovered a 400,000-year-old skull which bears strikingly similar features to a Neanderthal skull. The dating suggests, however, without the shadow of a doubt that this couldn’t be a Neanderthal.

Another mysterious hominid?

The partial skull was found in the Gruta da Aroeira cave, in Portugal in 2014 on the very last day of a field study led by Rolf Quam, an associate professor of biological anthropology at Binghamton University in New York. The site has been excavated ever since 1998 proving to be a great hub for middle Pleistocene fossils and artifacts. Along the years, researchers found in the Aroeira cave human teeth, animal remains and even stone-made hand axes. These stone-crafted tools were likely developed in the Middle East half a million years ago and these excavations prove that the technology spread to as far as Portugal within 100,000 years.

Hand axes crafted from stone discovered at the Aroeira site in Portugal. Credit: Rolf Quam.

Hand axes crafted from stone discovered at the Aroeira site in Portugal. Credit: Rolf Quam.

The prize find, however, is this peculiar skull which belonged to an unidentified species of Homo. 

“This is an interesting new fossil discovery from the Iberian Peninsula, a crucial region for understanding the origin and evolution of the Neanderthals,” Quam, an associate professor of anthropology at Binghamton University, State University of New York, said in a statement. “The Aroeira cranium is the oldest human fossil ever found in Portugal and shares some features with other fossils from this same time period in Spain, France and Italy.

The skull was found buried in the back of the cave in petrified sediment and recovering it proved to be a challenge. Imagine having to retrieve a delicate artifact that’s surrounded by concrete. Power tools and saws were used to cut a huge block which was later transferred to a research facility in Madrid, Spain. It took two and a half years to extract the skull in viable conditions, the researchers stated in their paper published in the Proceedings of the National Academy of Sciences.

Although only half of the skull was recovered, the other half was mirrored using CT scans of the cranium. This way, the researchers learned the skull, nicknamed the Aroeira cranium, has a cranial capacity of 1,100 cubic centimeters whereas you or I have an average capacity of 1,300 cubic centimeters. The skull also features the famous Neanderthal-shaped brow and a smaller bony projection behind the ear.  Two fragmentary teeth exhibit a mixture of traits, including some that are similar to those attributed to Neanderthals, and others to Homo erectus.

“Unlike most other Middle Pleistocene finds, which are of uncertain chronology, the Aroeira 3 cranium is firmly dated to around 400 ka and was in direct association with abundant faunal remains and stone tools. In addition, the presence of burnt bones suggests a controlled use of fire. The Aroeira cranium represents a substantial contribution to the debate on the origin of the Neandertals and the pattern of human evolution in the Middle Pleistocene of Europe,” the researchers concluded.

Whoever the skull used to belong to, this person must have looked more like a Neanderthal than a Homo Sapiens but was neither. Anthropologists are still debating the nature of this skull but some believe this is just another piece of evidence that Homo species exhibited great variation and regional combinations of traits across the Old World.

Another hypothesis, which is purely speculative at this point, is that the skull belongs to a new species of Homo. That’s not a very preposterous thing to suggest considering the mysterious Denisovans, likely a new species of human discovered in 2008, or the yet unexplained for Dmanisi hominins, the earliest human fossils found on the border of Asia and Europe. Then, there’s the case of two partial skulls both around 120,000 years old recovered from China which look like they belonged to an Asian Neanderthal — the species is also unidentified in this case.

Today, we humans are the only species alive from our genus but we do know for sure that we shared this planet at the same time with Neanderthals and Denisovans. Perhaps, there were far more.

How humans turned “safari” to “safe” – what large mammals diversity worldwide would look without us

The fact that the greatest biodiversity of large mammals we know of today is recorded in Africa is a legacy of past human activity, not climate or environmental phenomena, new study reveals. The paper theorizes at how the world today would look if Homo sapiens had never existed.

In a previous analysis, the researchers from Aarhus Univeristy, Denmark, they showed how the mass extinction of large mammals during the last Ice Age and the subsequent millennia, most notably the late-Quaternary megafauna extinction, is largely explainable by the expansion of modern humans across the world.

Building on the findings of their previous research, they imagine what the natural worldwide diversity patterns of mammals would be like in the absence of past and present human impacts. They base this human-free world on estimates of the natural distribution of each species according to its ecology and biogeography by overlapping it with the current natural environment template. The results suggest that in a world without us, most of northern Europe would probably now be home to more common animals such as wolves, Eurasian elk (moose) and bears, but also much larger mammals such as elephants and rhinoceroses. North and South America would also boast much more diverse populations of big mammals.

The natural diversity of large mammals is shown as it would appear without the impact of modern man (Homo sapiens). The figure shows the variation in the number of large mammals (45 kg or larger) that would have occurred per 100 x 100 kilometer grid cell. The numbers on the scale indicate the number of species.
Image via sciencedaily

“Northern Europe is far from the only place in which humans have reduced the diversity of mammals — it’s a worldwide phenomenon. And, in most places, there’s a very large deficit in mammal diversity relative to what it would naturally have been,” says Professor Jens-Christian Svenning, Department of Bioscience, Aarhus University, who is one of the researchers behind the study.

Africa, the final frontier

Current mammal diversity maps show that Africa is virtually the only continent where large mammals still boast good numbers and diversity. The world the researchers envisioned on the other hand shows far greater distribution of high large-mammal diversity across most of the world, particularly in North and South America, areas that are currently relatively poor in large mammals.

Image via wikipedia

“Most safaris today take place in Africa, but under natural circumstances, as many or even more large animals would no doubt have existed in other places, e.g., notably parts of the New World such as Texas and neighboring areas and the region around northern Argentina-Southern Brazil,” says Postdoctoral Fellow Soren Faurby, Department of Bioscience, Aarhus University, lead author on the study. “The reason that many safaris target Africa is not because the continent is naturally abnormally rich in species of mammals. Instead it reflects that it’s one of the only places where human activities have not yet wiped out most of the large animals.”

Africa then alarmingly becomes not the most-diverse continent due to climate or environment, but the one least un-diversified by humans. The underlying reasons cited by the team includes evolutionary adaptation of large mammals to humans as well as greater pest pressure on human populations in long-inhabited Africa in the past.

Platform to improve nature preservation

The study’s openly accessible data set of natural range maps for all late-Quatenary mammals gives scientists a powerful tool to analyse the natural patterns in the species diversity and composition of mammals worldwide. The data it shows can be used to provide a better understanding of the natural factors that determine the biodiversity in a specific area.

Today, there is a particularly large number of mammal species in mountainous areas. This is often interpreted as a consequence of environmental variation, where different species have evolved in deep valleys and high mountains. According to the new study, however, this trend is much weaker when the natural patterns are considered.

“The current high level of biodiversity in mountainous areas is partly due to the fact that the mountains have acted as a refuge for species in relation to hunting and habitat destruction, rather than being a purely natural pattern. An example in Europe is the brown bear, which now virtually only live in mountainous regions because it has been exterminated from the more accessible and most often more densely populated lowland areas,” explains Soren Faurby.

The study has been published in the scientific journal Diversity and Distributions.