Reconstructing how Neanderthals grew, based on an El Sidrón child

How did Neanderthals grow? Does modern man develop in the same way as Homo neanderthalensis did? How does the size of the brain affect the development of the body? A study led by the Spanish National Research Council (CSIC) researcher, Antonio Rosas, has studied the fossil remains of a Neanderthal child's skeleton in order to establish whether there are differences between the growth of Neanderthals and that of sapiens.

Neanderthal children may have grown up as slowly as modern humans 
[Credit: © S.Plailly, E.Daynes/LookatSciences]

According to the results of the article, which are published in Science, both species regulate their growth differently to adapt their energy consumption to their physical characteristics.

"Discerning the differences and similarities in growth patterns between Neanderthals and modern humans helps us better define our own history. Modern humans and Neanderthals emerged from a common recent ancestor, and this is manifested in a similar overall growth rate," explains CSIC researcher, Antonio Rosas, from Spain's National Natural Science Museum (MNCN). As fellow CSIC researcher Luis Ríos highlights, "Applying paediatric growth assessment methods, this Neanderthal child is no different to a modern-day child." The pattern of vertebral maturation and brain growth, as well as energy constraints during development, may have marked the anatomical shape of Neanderthals.

Neanderthals had a greater cranial capacity than today's humans. Neanderthal adults had an intracranial volume of 1,520 cubic centimetres, while that of modern adult man is 1,195 cubic centimetres. That of the Neanderthal child in the study had reached 1,330 cubic centimetres at the time of his death, in other words, 87.5% of the total reached at eight years of age. At that age, the development of a modern-day child's cranial capacity has already been fully completed.

"Developing a large brain involves significant energy expenditure and, consequently, this hinders the growth of other parts of the body. In sapiens, the development of the brain during childhood has a high energetic cost and, as a result, the development of the rest of the body slows down," Rosas explains.

Neanderthals and sapiens

The cost, in terms of energy, of anatomical growth of the modern brain is unusually high, especially during breastfeeding and during infancy, and this seems to require a slowing down of body growth. The growth and development of this juvenile Neanderthal matches the typical characteristics of human ontogeny, where there is a slow anatomical growth between weaning and puberty. This could compensate for the immense energy cost of developing such a large brain.

Skeleton of the Neanderthal boy recovered from the El Sidrón 
cave (Asturias, Spain) [Credit: Paleoanthropology Group 
MNCN-CSIC]

In fact, the skeleton and dentition of this Neanderthal present a physiology which is similar to that of a sapiens of the same age, except for the thorax area, which corresponds to a child between five and six years, in that it is less developed. "The growth of our Neanderthal child was not complete, probably due to energy saving," explains CSIC researcher Antonio Rosas.

The only divergent aspect in the growth of both species is the moment of maturation of the vertebral column. In all hominids, the cartilaginous joints of the middle thoracic vertebrae and the atlas are the last to fuse, but in this Neanderthal, fusion occurred about two years later than in modern humans.

"The delay of this fusion in the vertebral column may indicate that Neanderthals had a decoupling of certain aspects in the transition from infancy to the juvenile phase. Although the implications are unknown, this feature could be related to the characteristic enlarged shape of the Neanderthal torso, or slower brain growth," says Rosas.

The Neanderthal child

The protagonist of this study was 7.7 years old, weighed 26 kilos and measured 111 centimetres at the time of death. Although the genetic analyses failed to confirm the child's sex, the canine teeth and the sturdiness of the bones showed that it to be a male. 138 pieces, 30 of them teeth (including some milk teeth), and part of the skeleton- including some fragments of the skull from the individual- identified as El Sidrón J1, have recovered.

(Left to Right) Antonio García-Tabernero, Antonio Rosas and Luis Ríos beside the Neanderthal child's skeleton 
[Credit: Andrés Díaz-CSIC Communications Department]

The researchers have been able to establish that our protagonist was right-handed and was already performing adult tasks, such as using his teeth as a third hand to handle skins and plant fibres. In addition, they know who his mother was, and that the child protagonist of this investigation had a younger brother in the group. Furthermore, this child was found to have suffered from enamel hypoplasia when he was two or three years old. Hypoplasia (white spots on the teeth, especially visible in the upper incisors), occurs when the teeth have less enamel than normal, the cause usually being malnutrition or disease.

Discovered in 1994, the El Sidrón cave, located in Piloña (in Asturias, northern Spain) has provided the best collection of Neanderthals that exists on the Iberian Peninsula. The team has recovered the remains of 13 individuals from the cave. The group consisted of seven adults (four women and three men), three teenagers and three younger children.

Previous studies have been carried out by a multidisciplinary team led by the paleoanthropologist Antonio Rosas (CSIC's National Museum of Natural Sciences), the geneticist Carles Lalueza-Fox (Institute of Evolutionary Biology, run by CSIC and the Pompeu Fabra University) and by the archaeologist Marco de la Rasilla (University of Oviedo).

Source: Spanish National Research Council (CSIC) [September 22, 2017]

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Nymphaion in ancient city of Side undergoing restoration

Restoration and conversation is set to start again at the Monumental Fountain (Nymphaion) in the ancient city of Side in the southern Turkish province of Antalya.

The Nymphaion of Side [Credit: AA]

The Monumental Fountain dates back to the 2nd century AD and has undergone a series of restorations since 2004.

Antalya Surveying and Monuments Director Cemil Karabayram, who recently visited the ancient site, said only 20 percent of the restoration has so far been completed, but the work will be finished in the coming period.

Karabayram said a financial allocation for the project had been provided under the auspices of Culture and Tourism Minister Professor Numan Kurtulmuş, Foreign Minister Mevlüt Çavuşoğlu and Antalya Governor Münir Karalıoğlu, and a tender will be initiated in the coming days.

He said there are a number of large stone blocks in the area, which have each been documented with a separate number, adding that the blocks and the arch structure at the front of the site will be placed on the upper columns.

Karabayram said the restoration team strongly suspects that new blocks will be found under the layer of soil right behind the fountain.

“Excavations will unearth these new blocks. I hope that we will make the fountain complete by finishing the work. Tourists will be able to enter the area and visit the fountain. Almost 12 million Turkish Liras have been allocated for the entire Side region and its monumental structures,” he added.

The restoration team plans to restore the pool system in front of the fountain to its original state, while the asphalt in the gate of the castle, which is located at the entrance of Side, will be removed.

Karabayram said the excavations at the ancient site of Side were first initiated by Professor Arif Müfit Mansel, whose words and articles about Side are very important.

“Mansel said a copy of this fountain was constructed in Italy by Italians. Of course this was a matter of debate but we are carrying out work for it. We are talking with art historians about this issue, and whether the fountain here was a source of inspiration for the fountain in Rome,” he added.

Karabayram also said some columns of the fountain have been preserved throughout history.

“All of these columns are original and new materials will never be used in the restoration. But some extra blocks could be placed in order to provide balance,” he added.

Source: Hurriyet Daily News [September 22, 2017]

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Continued excavations of the Minoan Neopalatial complex at Sissi, Crete

A team of the Université Catholique de Louvain under the auspices of the Ephorate of Antiquities of Lasithi and the Belgian School at Athens, aided by experts and students from many Greek and foreign universities, continued the excavation of a monumental court-centered building on the Kephali-hill at Sissi (Lassithi, Crete) during the summer of 2017.

Aerial view of the court-centred complex at Sissi 
[Credit: © EBSA/N. Kress]

The entire complex largely dates to the Neopalatial period of the Minoan civilization, roughly the 16th c. BC, and was abandoned close in time to the Santorini eruption, ash of which was found within the building.

Started in 2015, we finally achieved the clearance of the plastered central court, which is seen to have a maximum size of 16.50 by 33 m.

Ritual Installations and paved corridor leading into court 
[Credit: © EBSA/J. Driessen]

Several ritual installations are found on and along this central court, which was directly accessible from the outside to the southwest via a finely paved corridor with ashlar walls.

The excavation further revealed large parts of the east and west wings of the complex; the latter also comprises a circular water-collecting basin with an associated subterranean cistern.

Fragments of ritual vase, probably a kernos, from the Central Court 
[Credit: © EBSA/Chronis Papanikolopoulos]

The excavation further identified an early phase of Mycenaean occupation (end of 15th c. BC) within the settlement while the exploration of the cemetery was continued.

Source: Belgian School at Athens [September 22, 2017]

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Ancient textiles reveal differences in Mediterranean fabrics in the 1st millennium BC

Textiles represent one of the earliest human craft technologies and applied arts, and their production would have been one of the most important time, resource and labour consuming activities in the ancient past.

Twill example from Civita Castellana, Italy, seventh century BC [Credit: Margarita Gleba]

In archaeological contexts, textiles are relatively rare finds, especially in Mediterranean Europe where conditions are unfavourable for organic material preservation. Many archaeological textile fragments do, however, survive in mineralised form, which forms the basis of a new study published in Antiquity.

Detailed analysis of several hundred textile fragments has provided, for the first time, a much more detailed definition of the textile cultures in Italy and Greece during the first half of the first millennium BC.

According to Dr Margarita Gleba, the study's author and researcher at the McDonald Institute for Archaeological Research, University of Cambridge, "Luckily for us, during the Iron Age (c. 1000-400 BC) people were buried with a lot of metal goods such as personal ornaments, weapons and vessels. These metals are conducive to the preservation of textiles as the metal effectively kills off the micro-organisms which would otherwise consume the organic materials, while at the same time metal salts create casts of textile fibres, thereby preserving the textile microstructure."

Weft-faced tabby example from Corfu, Greece, sixth century BC [Credit: Artex]

"This is how we get such a large number of textiles, even though they only exist now in tiny fragments. Through meticulous analysis using digital and scanning electron microscopy, high performance liquid chromatography and other advanced methods we are able to determine a lot of information including the nature of the raw materials and structural features such as thread diameter, twist direction, type of weaving or binding, and thread count."

The technical differences suggest that during the Iron Age, textiles in Italy more closely resembled those found in Central Europe (associated with the Hallstatt culture that was prevalent in modern-day Germany, Austria and Slovenia) while the textile culture of Greece was largely connected with the Near East.

Dr Gleba added, "There is overwhelming evidence for frequent contact between Italy and Greece during the first half of the first millennium BC, but this evidence shows that their textile traditions were technically, aesthetically and conceptually very different. This means that the populations in these two regions are making an active decision to clothe themselves in a certain way and it may have to do with traditions set up already in the Bronze Age."

"Textiles have been and still are widely considered one of the most valuable indicators of individual and group identity. Even in societies today, we frequently form opinions of others based on the type of cloth they are wearing: tweed is associated with Irish and British country clothing, cashmere with Central Asia and silk with the Far East for example."

"Curiously, by Roman times, the establishment of Greek colonies in southern Italy and more general oriental influences observed in material culture of Italic populations leads towards gradual disappearance of the indigenous textile tradition. Our future research will attempt to understand the cause behind this change in textile culture."

Source: University of Cambridge [September 21, 2017]

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Ancient human DNA in sub-Saharan Africa lifts veil on prehistory

The first large-scale study of ancient human DNA from sub-Saharan Africa opens a long-awaited window into the identity of prehistoric populations in the region and how they moved around and replaced one another over the past 8,000 years.

Mount Hora in Malawi, where the oldest DNA in the study, from a woman who lived more than 8,000 years ago, 
was obtained [Credit: Jessica C. Thompson/Emory University]

The findings, published Cell by an international research team led by Harvard Medical School, answer several longstanding mysteries and uncover surprising details about sub-Saharan African ancestry—including genetic adaptations for a hunter-gatherer lifestyle and the first glimpses of population distribution before farmers and animal herders swept across the continent about 3,000 years ago.

"The last few thousand years were an incredibly rich and formative period that is key to understanding how populations in Africa got to where they are today," said David Reich, professor of genetics at HMS and a senior associate member of the Broad Institute of MIT and Harvard. "Ancestry during this time period is such an unexplored landscape that everything we learned was new."

Reich shares senior authorship of the study with Ron Pinhasi of the University of Vienna and Johannes Krause of the Max Planck Institute for the Science of Human History and the University of Tübingen in Germany.

"Ancient DNA is the only tool we have for characterizing past genomic diversity. It teaches us things we don't know about history from archaeology and linguistics and can help us better understand present-day populations," said Pontus Skoglund, a postdoctoral researcher in the Reich lab and the study's first author. "We need to ensure we use it for the benefit of all populations around the world, perhaps especially Africa, which contains the greatest human genetic diversity in the world but has been underserved by the genomics community."

Long time coming

Although ancient-DNA research has revealed insights into the population histories of many areas of the world, delving into the deep ancestry of African groups wasn't possible until recently because genetic material degrades too rapidly in warm, humid climates.

Technological advances—including the discovery by Pinhasi and colleagues that DNA persists longer in small, dense ear bones—are now beginning to break the climate barrier. Last year, Reich and colleagues used the new techniques to generate the first genome-wide data from the earliest farmers in the Near East, who lived between 8,000 and 12,000 years ago.

Genomic time-lapse

Almost half of the team's samples came from Malawi, providing a series of genomic snapshots from the same location across thousands of years.

This visual abstract depicts the findings of Skoglund et al. In their paper, the prehistory of African populations is explored 
by genome-wide analysis of 16 human remains providing insight into lineages, admixture, and genomicadaptions 
[Credit: Skoglund et al./Cell 2017]

The time-series divulged the existence of an ancient hunter-gatherer population the researchers hadn't expected.

When agriculture spread in Europe and East Asia, farmers and animal herders expanded into new areas and mixed with the hunter-gatherers who lived there. Present-day populations thus inherited DNA from both groups.

The new study found evidence for similar movement and mixing in other parts of Africa, but after farmers reached Malawi, hunter-gatherers seem to have disappeared without contributing any detectable ancestry to the people who live there today.

"It looks like there was a complete population replacement," said Reich. "We haven't seen clear evidence for an event like this anywhere else."

The Malawi snapshots also helped identify a population that spanned from the southern tip of Africa all the way to the equator about 1,400 years ago before fading away. That mysterious group shared ancestry with today's Khoe-San people in southern Africa and left a few DNA traces in people from a group of islands thousands of miles away, off the coast of Tanzania.

"It's amazing to see these populations in the DNA that don't exist anymore," said Reich. "It's clear that gathering additional DNA samples will teach us much more."

"The Khoe-San are such a genetically distinctive people, it was a surprise to find a closely related ancestor so far north just a couple of thousand years ago," Reich added.

The new study also found that West Africans can trace their lineage back to a human ancestor that may have split off from other African populations even earlier than the Khoe-San.

Missing links

The research similarly shed light on the origins of another unique group, the Hadza people of East Africa.

"They have a distinct appearance, language and genetics, and some people speculated that, like the Khoe-San, they might represent a very early diverging group from other African populations," said Reich. "Our study shows that instead, they're somehow in the middle of everything."

The Hadza, according to genomic comparisons, are today more closely related to non-Africans than to other Africans. The researchers hypothesize that the Hadza are direct descendants of the group that migrated out of Africa, and possibly spread within Africa as well, after about 50,000 years ago.

Another discovery lay in wait in East Africa.

Scientists had predicted the existence of an ancient population based on the observation that present-day people in southern Africa share ancestry with people in the Near East. The 3,000-year-old remains of a young girl in Tanzania provided the missing evidence.

Reich and colleagues suspect that the girl belonged to a herding population that contributed significant ancestry to present-day people from Ethiopia and Somalia down to South Africa. The ancient population was about one-third Eurasian, and the researchers were able to further pinpoint that ancestry to the Levant region.

"With this sample in hand, we can now say more about who these people were," said Skoglund.

The finding put one mystery to rest while raising another: Present-day people in the Horn of Africa have additional Near Eastern ancestry that can't be explained by the group to which the young girl belonged.

Natural selection

Finally, the study took a first step in using ancient DNA to understand genetic adaptation in African populations.

It required "squeezing water out of a stone" because the researchers were working with so few ancient samples, said Reich, but Skoglund was able to identify two regions of the genome that appear to have undergone natural selection in southern Africans.

One adaptation increased protection from ultraviolet radiation, which the researchers propose could be related to life in the Kalahari Desert. The other variant was located on genes related to taste buds, which the researchers point out can help people detect poisons in plants.

The researchers hope that their study encourages more investigation into the diverse genetic landscape of human populations in Africa, both past and present. Reich also said he hopes the work reminds people that African history didn't end 50,000 years ago when groups of humans began migrating into the Near East and beyond.

"The late Stone Age in Africa is like a black hole, research-wise," said Reich. "Ancient DNA can address that gap."

Source: Cell Press [September 21, 2017]

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