Tuesday, May 24, 2016

What children have told Neanderthal skeletons – BBC

In the latest issue of the prestigious scientific journal PNAS published research , telling about the results of the study of the skeleton of the newborn Neanderthal who died at the age of two weeks. Some of the study’s authors, from St. Petersburg archaeologists Love Golovanov Vladimir Doronichev, told the science department on the work

-. In the course of your studies you last studied the skeletons of Neanderthal children. Why is it important to study the skeletons of children is

– One of the oldest and most important questions in human evolutionary studies is the question: why Neanderthals differed from modern humans? While this issue can be solved in different ways, for a complete answer requires an understanding that formed differences inherent in adult individuals.

The answer to this question can only give the study of children in individual development skeletons.

Based on numerous studies of skulls of adult and adolescent specimens of Neanderthals, as well as previously published results of studying Neanderthal child skull of Mezmaiskaya cave (Absheron district of Krasnodar region), is now well known that many differences between the skull structure (ie cranial skeleton) Neandertal and modern humans are already present at birth, that is, the differences being laid at the stage of embryo maturation. However, we are much less aware about how and at what stage of development are formed by differences in other parts of the body, which are called collectively postcranial (meaning “headless”) skeleton.

In this research were studied two of the most complete today postcranial skeleton newborn Neanderthal. One of them was found in 1993 during archaeological excavations under the direction of Lyubov Golovanova parking Neanderthals in Mezmaiskaya cave.

Another was discovered in 1914 during excavations under the direction of D. Peyronie parking Neanderthals in the canopy of Le Moustier, France . For a long time it was thought that the French find was lost during the Second World War, and only in 1996 it was “secondary” opened with an inventory of museum collections in the Museum of Prehistory of Le Zezi Teyyak de Sireuil. Age of Neanderthal Mezmaiskaya cave is only two weeks after the birth. Now it is not only the youngest Neanderthal, but also the most complete and well-preserved skeleton of a Neanderthal man of any age in the world.

Baby Neanderthal from Le Moustier was no more than 4 months after birth.

The main the result of this research is to clearly establish the fact that many of the features in the shape and structure of the body of Neanderthals, which mainly distinguish them from modern humans were already present at birth, that is, as in the case of the skull, especially post-cranial skeleton Neanderthals formed at the stage of the embryo maturation. This study provides an indisputable argument in support of conventional science theory that differences of Neanderthals and modern humans have a deep evolutionary significance, that is, they are due to natural selection, and are not the result of lifetime behavioral adaptations

-. A why it is so rarely find children’s skeletons of Neanderthals

-? Found fossils of human bones in general phenomenon in science is quite rare, and the deeper into the past, the less these findings. There are several reasons. First, until the end of the Paleolithic era (ie the ancient Stone Age, which covers more than 99% of human history, from 2.5 million years to 10 thousand. Years ago), there are steam rooms, and then the collective burial of people, the earliest of that have an age of no more than 30-25 thousand. years (for example, the famous pair burial parked Sungir under Vladimir).

Neanderthals buried their dead, but it is always single burials on parking.

Second, the impact of environmental factors of different intensity and scale of large rearrangements of the landscape of whole regions to chemical and biochemical erosion activity of worms and microorganisms leading to full or partial destruction of organic materials (including including bones) on many parking lots, where scientists collected only stone tools. In general, the trend is that the preservation of the fossil bones worse than their old age, although there are numerous exceptions. Typically better than other bones of the skeleton are preserved teeth, enamel-coated durable and stronger joint and bone fragments of long bones. Brittle bones is much easier for children susceptible to damage than adult bones, so they are much less common. For example, in Mezmaiskaya cave

a newborn Neanderthal skeleton was preserved to a large extent due to the fact that he was vtsementirovan in solid calcite-carbonate breccia,

the composition and origin of which is the same as that of well-known cave sinters, stalagmites and stalactites. If not this stone “armor”, hardly we could find at least a few bones of the newborn.

In Mezmaiskaya cave, situated high in the mountains (1310 meters above sea level), we see a unique preservation of the bones, especially compared to the other sites of this age. This provides the possibility of genetic research. Sample Mezmayskoe Neanderthal (Mezmay 1) participated in the determination of the genome of Neanderthals, are currently under study one of the most advanced Neanderthals (Mezmay 2). The bones of the bison Mezmaiskaya cave participated in the definition of bison genome and species diversity. In fact, Mezmaiskaya cave is a unique pantry genetic material for future research. That’s not counting the fact that Mezmaiskaya cave is a world famous archaeological monument, a place where lived the Neanderthals from 70 to 40 thousand. Years ago, where we have evidence of habitation of early Homo sapiens from 39 to 11 thousand. Years ago.

Articles about this monument are published in leading publications in Russia and abroad.

Unfortunately, this monument of history and culture completely protected.

Every year, it is destroyed in the result of economic activity (logging), and as a result of visits by numerous unorganized groups of tourists, which burn the fires, dig on the monument of world importance. Officially Mezmaiskaya cave has only number in the register of monuments of history and culture of the Krasnodar Territory, although the monument is found and studied for almost 30 years, in 2017 will be birthday. There are no maps or documents on the situation of the monument and the protected area, so in the case of destruction the Office for the Protection of Monuments of History and Culture of the Krasnodar Territory can not even bring the perpetrators to justice. We filed an application to the Ministry of Culture on “Project delineate areas of cultural heritage”, but were refused. Regional programs also do not support the current work on the conservation of monuments under the pretext that all archaeological sites is considered a monument of federal importance and should be financed from the federal budget

Getting back to your question -. Why so rarely find children’s skeletons of Neanderthals, You can only observe,

that such an approach to the protection of the unique monuments in the near future there will be and the monuments themselves.

– What does it mean “to be born a Neanderthal?” Child Neanderthal immediately be distinguished from modern man? On what grounds

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– As we have already said, , this and other studies suggest that the morphological features of not only the skull, but the post-cranial skeleton Neanderthals are formed at an early (embryonic or prenatal) stage of the process of individual development. In other words, any individual Neanderthal will always appear as the representative of the kind of Neanderthal, regardless of its individual age after birth. Yes, anthropologists, scientists always will distinguish Neanderthal child from the child of modern man. For this there are many signs. Previously, the basis for the specific diagnosis of Neanderthals were signs of the skull, such as low and wide skull cap with a sloping frontal bone protruding occipital bone, no chin, greatly extending the front skull is different from modern man the structure of the inner ear, large spade chisels with biconical inner surface and others. The study of postcranial skeletons of Neanderthal children added new features.

Among these are the most significant wide body, long pubic bone, massive long bones, short tibia relative to the length of the femur.

– What do you personally have been unexpected, unusual in the results of a new study

-? We have been cooperating with leading European experts who deal problems of the evolutionary history of human resources. Many of these studies have already been published. These publications are widely used and cited by experts of different scientific disciplines. This study is another building block in the emerging before our eyes the evolutionary history of mankind.

Perhaps the most unusual aspect of this work for us was that our colleagues from France, the US and Germany have taken as a material for comparison with Neanderthals data on adult and newborn North Americans, have a European or African origin.

Comparison of linear parameters of bone between European Americans and African Americans shows almost the same differences in the structure of the body, which other researchers We mentioned among the geographic populations of modern humans, living either in the high or in the low latitudes.

And these differences are clearly not available due to habitat and various origins and genetic inheritance of traits that were formed from ancient ancestors as a result of adaptation to a completely different natural conditions in Europe and Africa. At the same time the Neanderthals (as well as expected) were closest to the native Europeans descendants

-. In the past you have expressed the hypothesis that Neanderthals became extinct in Europe before there came sapiens …

– in our earlier work (article in Current Anthropology, published in 2010), we have deliberately not touched the issues of spatial and temporal relations sapiens and Neanderthals in Europe. Our article was devoted only Neanderthals and the factors that could lead to their extinction. The influence factor of modern man in the disappearance of Neanderthals we mentioned, since many scientists both here and abroad believe that it was decisive.

We do not agree, in principle, since modern study of Paleolithic sites do not show reliable evidence of the coexistence of Neanderthals and sapiens.

In most cases, the monuments of the remains lie above the parking sapiens Neanderthal sites, indicating that sapiens lived here later

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As for the time, the disappearance of the Neanderthals 40 thousand years ago, is now recognized by so many experts, if not an absolute majority of scientists. Also, there is little doubt that the sapiens emerged in some parts of Europe for a 2-3 thousand. Years before. We do also never denied. However, these were few representatives of sapiens, but because the climate crisis has not affected the entire population of Homo sapiens, can not be said about the Neandertal

-. Once you mentioned that Neanderthals became extinct as a result of a volcanic winter. Can you tell us more about this volcanic winter

-? The phenomenon of volcanic winter, as the term itself, coined not by us. More information about this is written in the above article in Current Anthropology. Speaking a few words, volcanic winter – it is very sharp and an extremely strong cooling of the climate as a result of emissions into the atmosphere huge amounts of volcanic ash. As a result of chemical reactions in the atmosphere creates a layer of secondary aerosols that reflect sunlight and creates an effect opposite to the greenhouse.

The last eruption, which caused such an effect on a global scale, which affected almost all Eurasia and North America, then uninhabited, was just about 40 thousand. years ago.

Recent studies of direct data obtained directly from the sites of the people of that time and with the use of computer programs simulations show that the direct effect of this eruption was short-lived (1-2 years) and there was a cold snap too extreme (from -3 to -5 degrees in annual terms) in most regions of Europe and the Middle East, where Neanderthals lived. However, in all regions of the peninsula in the west to the Don and Kuban basin in the east, where for the time fixed by a layer of volcanic ash, higher ash parking Neanderthals disappear. They disappear at the same time, and in other areas where the ash layer is not fixed. Here we mean the complete and final extinction of the Neanderthals, rather than the process of reducing their habitat, with its attendant local disappearances, which began before approximately five thousand years.

Extinction Neanderthals has a clear geological age -. about 40 thousand years ago, when it happened superizverzhenie global effect.

By the way, this is the only superizverzhenie in Europe in the history of Neanderthal habitat. And they have become extinct, we believe, primarily because their population was subjected to mass extinction in those regions that have experienced the greatest impact of volcanic winter. A further population of Neanderthals lost the ability to reproduce (there is such a thing – the reproductive population size below which the population dies out). Accordingly, it was followed by a series of local disappearances (domino effect), which ended in the complete disappearance of the Neanderthals. This whole process of extinction happened very quickly. Several generations … and there is no Neanderthal

-. A modern mother would bring up a Neanderthal child

-? Theoretically, yes. After all, in the genome of modern humans-non-Africans there is about 1-3% Neanderthal genes. We all know that modern mammals “adopt” young of other species. Although, based on current knowledge about the diet of Neanderthals, we can assume that the composition of breast milk they had another.

However, some evidence suggests that the modern woman could hardly make a Neanderthal child, the case is likely to It would end in miscarriage. It’s one thing when Neanderthals genes fall into the gene pool of modern humans as a result of casual sex first and second.

quite another – to use the modern woman as a surrogate mother for the birth of 100 – interest of the child Neanderthal

-. What of the Neanderthals in every reader “Gazety.Ru»

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the same 1-3% Neanderthal genes inherited from our ancestors

Unless, of course, among your readers do not have indigenous Africans

They -.. one hundred percent Homo sapiens

– As passed your cooperation with foreign colleagues ? How long have you been working on the study

-? This article is the result of an international team of scientists from France, the USA, Germany and Russia. Work continued for several years.

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