European-Neanderthal Sex Detailed in Ancient DNA

Where we come from? Which are our origins? Nowadays continues to be debated. To shed light on the origins of modern Europeans scientists had analyzed ancient DNA which reveals that there is a surprising genetic unity between the earliest known Europeans and contemporary Europeans, explaining when modern humans interbred with Neanderthals, our closest extinct relatives.

The skull of a man who lived between 36,200 and 38,700 years ago in Kostenki in western Russia

They had analyzed the DNA from the left shinbone of a skeleton, known as K14. K14 is one of the oldest fossils of a European modern human —36,200 and 38,700— and was found in the area that's now Kostenki, western Russia. The complete genome has been sequenced, making it the second-oldest modern human genome ever sequenced. The oldest was from the 45,000-year-old thighbone of a man found in western Siberia.

Surprisingly, the researchers found that contemporary Europeans shared genetic continuity with ancient Europeans.

The study found that K14's DNA holds about 1% more Neanderthal DNA than modern human. The result was expected by scientists, because if there has been any Neanderthal ancestry that humans might have, have diluted over time once Neanderthals went extinct.

People don’t know that 1.5 to 2.1 percent of our DNA — from Europe to Asia to the Americas — has Neanderthal origin. Genetic data from the research suggest that modern humans and Neanderthals interbred about 54,000 years ago, before the modern human population in Eurasia began to separate. 

However, there are evidences that modern humans co-lived with Neanderthals for another 10,000 years. But instead, very little, if any, additional interbreeding occurred. So these give rise to the question “Are the Neanderthals more close to us that we thought?” Or now knowing that they interbreed among them, why so little? Robert Foley states "It's an extraordinary finding that we don't understand yet”.

The Incredible Human Journey series

 The Incredible Human Journey is a five-episode science documentary and accompanying book, written and presented by Alice Roberts. It was first broadcast in May and June 2009 in the UK. It explains the evidence for the theory of early human migrations out of Africa and subsequently around the world, supporting the Out of Africa Theory. This theory claims that all modern humans are descended from anatomically modern African Homo sapiens rather than from the more archaic European and Middle Eastern Homo neanderthalensis or the indigenous Chinese Homo pekinensis, and that the modern African Homo sapiens did not interbreed with the other species of genus Homo. Each episode concerns a different continent, and the series features scenes filmed on location in each of the continents featured.

This interesting documentary series is available online for free and we have a link to watch them in our blog: watch The Incredible Human Journey

Chronic disease risk

The most significant differences between human and a chimp could be, size, hair and brain. But, if we take into account the microscopic world, DID YOU COUNT YOUR MICROBIOME?

It is not just the surface that we are different

What modified our gut flora so dramatically? changing diets and habitats probably both played a role.

They found that a loss of microbial diversity appears to have sped up suddenly in modern humans, “divergence of the microbiome from the microbiome of apes, and a drastic loss of diversity of the microbial community," says Thomas Bosch of the Christian Albrechts University in Kiel, Germany.

In one hand, among the bugs we have lost are a number that help digest plant matter, while in the other hand, we have gained others that help us digest meat. That makes sense in light of our diet.

"Other work has shown if you can't digest complex plant polysaccharides, they sit around in the gut where they can cause inflammation," he says. "So not having certain bacteria could make people more predisposed to chronic inflammation".

For now, all these possible links between the microbiome and our health still need to be firmed up with more studies.

"The new study demonstrates that divergence of humans from great apes was accompanied by the establishment of a completely different, human-specific microbiome," says Bosch. "Whether this change of the micobiome was one of the key drivers of human evolution and the development of human specific features remains to be shown."

Humans Would Beat Neanderthals in Marathon

Who would win if a modern human and a Neanderthal competed in a marathon? A curious question, but which is the answer?

We know that Humans, versus other great apes, are built for running fast and long as opposed to very impressive strength, but what about Neanderthals?

In a research made by the Journal of Human Evolution suggested that In a short sprint, the Neanderthal might have had a chance, but most fit humans would always win longer races.

Nowadays the human (Usain Bolt) has achieve a mark of 9.58s in 100m. But the anthropologist David Raichlen of the University of Arizona and his colleagues said us that our modern human ancestors were better runners. The research was carry out by studying the hominids'fossilized remains.

Neanderthal - not built for long distance running.

Recent research suggests that the energy cost of running at a given speed is strongly related to the length of certain limb bones. The longer these bones are, the more energy it takes for the individual to run.

We know that exist an inherent trade-off between speed and strength throughout the animal kingdom. So that way they deduced that Neanderthals were built more for brawn, with humans evolving lighter, more aerodynamic bodies for running.

PROPOSAL: A hypothetical Summer Olympics (Neanderthals vs. Humans)

It would be a memorable event as the year that Usain Bolt got the WR in Berlin, Germany. In those Olympics, Neanderthals probably had been the stars of events like wrestling, rowing and archery, and humans winning cycling, triathlon and marathon competitions. CAN YOU IMAGINE?

How we tamed ourselves and became modern?

Call a man "tame" or "domesticated" and he's not likely to take it as a compliment. But all of us, male and female, may have to get used to it: At a high-level meeting earlier this month, scientists argued that "self-domestication" was a key process in the evolution of our species. They noted that with our reduced jaws, flat faces, and lower male aggression, humans are to chimps as dogs are to wolves, showing many of the physical traits that emerge during animal domestication. 

Big brow ridges and teeth suggest that ancient Homo heidelbergensis(above) may have had more testosterone than modern Homo sapiens (left).

The accompanying changes in behavior, especially among men, might have helped humans evolve more complex language, live atop each other in cities, and work together to create sophisticated cultures.

No one set out to domesticate humans, of course. But at the first-ever symposium on self-domestication of humans, held at the Salk Institute for Biological Studies, researchers outlined a set of linked behavioral and anatomical changes seen both in animals that humans have tamed and in creatures that have tamed themselves, such as bonobos.

Cave Paintings in Indonesia Redraw Picture of Earliest Art

The dating discovery recasts ancient cave art as a continent-spanning human practice.

The art shown here has not been dated, but is stylistically similar to other art in the area now found to be around 40,000 years old.

A hand painted in an Indonesian cave dates to at least 39,900 years ago, making it among the oldest such images in the world, archaeologists reported in a study that rewrites the history of art.

The discovery on the island of Sulawesi vastly expands the geography of the first cave artists, who were long thought to have appeared in prehistoric Europe around that time. Reported in the journal Nature, the cave art includes stencils of hands and a painting of a babirusa, or "pig-deer," which may be the world's oldest figurative art. 

"Overwhelmingly depicted in Europe and Sulawesi were large, and often dangerous, mammal species that possibly played major roles in the belief systems of these people," says archaeologist and study leader Maxime Aubertof Griffith University in Queensland, Australia. 

The finds from the Maros cave sites on Sulawesi raise the possibility that such art predates the exodus of modern humans from Africa 60,000 or more years ago.

"I predict that even older examples of cave art will be discovered on Sulawesi, and in mainland Asia, and ultimately in our African homeland," says human origins expert Chris Stringer of the Natural History Museum in London, who was not on the study team.

The oldest dated hand stencil in the world and possibly the oldest figurative depiction in cave art— a pig-deer)—were found in Leang Timpuseng cave in Sulawesi. 

Rapid expansion of human

Model of human brain

A new study could rewrite the story of ape and human brain evolution. While the neocortex of the brain has been called "the crowning achievement of evolution and the biological substrate of human mental prowess," newly reported evolutionary rate comparisons show that the cerebellum expanded up to six times faster than anticipated throughout the evolution of apes, including humans.

The findings suggest that technical intelligence was likely at least as important as social intelligence in human cognitive evolution, the researchers say.

"Our results highlight a previously unappreciated role of the cerebellum in ape and human brain evolution that has the potential to refocus researchers' thinking about how and why the brains in these species have become distinct and to shift attention away from an almost exclusive focus on the neocortex as the seat of our humanity," says Robert Barton of Durham University in the United Kingdom.

"In humans, the cerebellum contains about 70 billion neurons -- four times more than in the neocortex," Barton says. "Nobody really knows what all these neurons are for, but they must be doing something important."

The neocortex had gotten most of the attention in part because it is such a large structure to begin with. As a result, in looking at variation in the size of various brain regions, the neocortex appeared to show the most expansion. But much of that increase in size could be explained away by the size of the animal as a whole. Sperm whales have a neocortex that is proportionally larger than that of humans, for example.

Barton and Venditti say that the cerebellum seems to be particularly involved in the temporal organization of complex behavioral sequences, such as those involved in making and using tools, for instance. Interestingly, evidence is now emerging for a critical role of the cerebellum in language, too.

While plenty of work remains, the new study establishes the cerebellum as "a new frontier for investigations into the neural basis of advanced cognitive abilities," the researchers say.

Humanity Has More Mothers Than Fathers, DNA Reveals

Mothers outnumbered fathers throughout much of human history, a new DNA analysis of people around the world shows. The genetic findings offer evidence for polygyny, when one man has many wives, and other reproductive customs, as people migrated out of Africa.

"Historically more of the women were reproducing than the men," study researcher Mark Stoneking, a professor of biological anthropology at the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, said. "This often happens in human societies, because not all men are able to afford wives, or sometimes a few men will have many wives." These practices resulted in females making a larger genetic contribution to the global population than males did, the researchers found.

Stoneking and colleagues used a new method to scrutinize genetic variation within the male Y-chromosome. By looking at one part of the Y chromosome, they found all of the genetic variants, or slight differences in the order of DNA's "letters," within that region.

Credit: razlomov | Shutterstock

He and his colleagues put their new technique to work on DNA samples of 623 males from 51 populations around the world, including Australian, European, and American populations. The new method allowed them to take the DNA samples from each male and compare the paternally inherited Y chromosome (NRY), which gets passed down from father to son, with mitochondrial DNA (mtDNA), which mothers pass down to their children, Stoneking said.

Women likely traveled for marriages, leaving their hometowns and moving in with their husbands, the genetic analysis showed. So, females migrated more than males did, spreading their female mitochondrial DNA far and wide and reducing genetic variability between populations. Men, in contrast, tended to stay put, which resulted in their sons having distinct genes in each population.

On a regional scale, the DNA samples showed a detailed story. For example, people in East Asia and Europe have larger genetic differences for paternal than for maternal DNA, suggesting high levels of female migration. In contrast, populations in Africa, Oceania and the Americas have bigger differences for maternal DNA than for paternal DNA.

Via LiveScience: http://www.livescience.com/47976-more-mothers-in-human-history.html
Full article in Investigative Genetics: http://www.investigativegenetics.com/content/5/1/13

Third Branch Added To Present-Day European Family Tree

Some 7,500 years ago, brown-eyed, pale-skinned farmers began migrating into Europe from the Near East. These migrants not only spread a new way of life to the resident blue-eyed, dark-skinned hunter-gatherers through the introduction of agriculture, but they also contributed their DNA by interbreeding along the way. Genetic analysis suggested that modern Europeans descended from the mixing of these two distinct populations, but this was largely based on samples from living people. Now, thanks to DNA samples from ancient humans, scientists have revealed that there was in fact a third party on the scene: ancient north Eurasians.

For the new study, scientists from Harvard Medical School and the University of Tübingen sequenced the DNA of 2,345 present-day humans from all over the world alongside that of several ancient humans from Sweden, Luxembourg and Germany.

 Joanna Drath (Univ. of Tübingen). Skull of a 7,000-year-old farmer from Germany.

They found that ancient north Eurasian DNA was not present in the hunter-gatherers, nor the early farmers, suggesting this population arrived on the scene later. However, almost all modern Europeans have DNA from all three ancient groups. According to first author of the Nature study Iosif Lazaridis, differences in present-day Europeans can be attributed to the relative proportions of ancestry. “Northern Europeans have more hunter-gatherer ancestry—up to about 50 percent in Lithuanians—and Southern Europeans have more farmer ancestry,” he added.

While ancient north Eurasian ancestry never made up more than 20% of the ancestry of present-day Europeans, it was found in virtually every group studied. Interestingly, this new population on the block was previously only known from traces of DNA in present-day humans and thus was considered a “ghost population.” However, the discovery of two ancient north Eurasians by a separate group in January allowed the researchers to investigate relationships with other populations for the first time.

Unfortunately, this study was limited by the small number of ancient specimens available for analysis, meaning some questions are left unanswered.

Article in IFLS: http://www.iflscience.com/plants-and-animals/third-branch-added-present-day-european-family-tree

Full article in Nature: http://www.nature.com/nature/journal/v513/n7518/full/nature13673.html