EPIGRAFIA E CONCHIGLIE (Yahweisti:vi sto dando un'idea, eh?)

 Oldest ever engraving discovered on 500,000-year-old shell

Homo erectus on Java was already using shells of freshwater mussels as tools half a million years ago, and as a 'canvas' for an engraving. An international team of researchers, led by Leiden archaeologist José Joordens, published this discovery on 3 December in Nature. The discovery provides new insights into the evolution of human behaviour. 

Detail of the engraving on fossil Pseudodon shell (DUB1006-fL) from Trinil [Credit: Wim Lustenhouwer, VU University Amsterdam] 

Not only Homo sapiens made engravings "Until this discovery, it was assumed that comparable engravings were only made by modern humans (Homo sapiens) in Africa, starting about 100,000 years ago," says lead author José Joordens, researcher at the Faculty of Archaeology at Leiden University. 
A team of 21 researchers studied hundreds of fossil shells and associated finds and sediments from the Homo erectus site Trinil, on the Indonesian island of Java. The shells are part of the Dubois Collection that has been held at the Naturalis Biodiversity Center since the end of the 19th century. 
The shells were excavated by the Dutch physician and researcher Eugène Dubois, the discoverer of Pithecanthropus erectus -- now known as Homo erectus. Engravings older than weathering The discovery of an engraved geometrical pattern on one of the shells came as a total surprise.
 The zig zag pattern, that can only be seen with oblique lighting, is clearly older than the weathering processes on the shell arising from fossilisation. 
The study has excluded the possibility that the pattern could have been caused by animals or by natural weathering processes and shows that the 'zigzag' pattern is the work of Homo erectus. 

The fossil Pseudodon shell (DUB1006-fL) with the engraving made by Homo erectus at Trinil  [Credit: Wim Lustenhouwer, VU University Amsterdam] 

Five hundred thousand years old By applying two dating methods, researchers at the VU University Amsterdam and Wageningen University have determined that the shell with the engraving is minimally 430,000 and maximally 540,000 years old.
This means that the engraving is at least four times older than the previously oldest known engravings, found in Africa. Purpose or meaning of the engraving? "It's fantastic that this engraved shell has been discovered in a museum collection where it has been held for more than a hundred years. I can imagine people may be wondering whether this can be seen as a form of early art," says Wil Roebroeks, Professor of Palaeolithic Archaeology at Leiden University. 
He was able to finance this long-term research with his NWO Spinoza Prize. "At the moment we have no clue about the meaning or purpose of this engraving." 

Inside of the fossil Pseudodon shell (DUB7923-bL) showing that the hole made by  Homo erectus is exactly at the spot where the adductor muscle is attached to the shell  [Credit: Henk Caspers, Naturalis, Leiden, The Netherlands] 

Early human-like mussel collector 
This research has shown that these early human-like people were very clever about how they opened these large freshwater mussels; they drilled a hole through the shell using a sharp object, possibly a shark's tooth, exactly at the point where the muscle is attached that keeps the shell closed. 
"The precision with which these early humans worked indicates great dexterity and detailed knowledge of mollusc anatomy," says Frank Wesselingh, a researcher and expert on fossil shells at Naturalis. 
The molluscs were eaten and the empty shells were used to manufacture tools, such as knives. 
Possible follow-on research This discovery from the historical Dubois collection sheds unexpected new light on the skills and behaviour of Homo erectus, and indicates that Asia is a promising and, so far, relatively unexplored area for finding intriguing artefacts. 
From the Netherlands, researchers at Leiden University, the Naturalis Biodiversity Center, the Vrije Universiteit Amsterdam, the universities of Wageningen and Delft and the Cultural Heritage Agency of the Netherlands were involved in the research. 
This research is being financed by research funding from the NWO Spinoza Prize. 
The shell with the oldest known human engraving will be on display in the Naturalis museum from 4 December onward. 

Source: Leiden University [December 03, 2014]

WISHFUL THINKING, NE VOGLIAMO PARLARE?

Lo 'Hobbit' non esiste! 

Qualcuno già lo sospettava forse. Ma si riferiva 

probabilmente al personaggio inventato da Tolkien.

Antefatto.

Nel 2004 si gridò al miracolo: era stato scoperta una nuova - 

prima sconosciuta - specie di Uomo, nell'isola di Flores, 

Indonesia: fu definito "Homo Florensis". Se ne fecero persino

 ricostruzioni varie, immaginandolo come un piccolo essere

 umano attorno al metro di altezza, con grossi piedi un

 piccolo cervello (meno di 380 ml:  meno di 4 bicchieri

 d'acqua, un terzo di un encefalo normale) in un piccolo 

cranio ed un aspetto da Hobbit. 

Wishful thinking - certamente - considerando che ciò che

se ne era trovato comprendeva solamente un femore ed un

cranio ricostruito, rinvenuti nella grotta di Liang Bua (da

cui la sigla che indica il reperto: LB1).

Errori di metodo.

Anche se LB1 visse 'solamente' 15.000 anni fa, ne sono stati

 tratti confronti con Homo Erectus e addirittura con

 l'Australopitecus.

La rivalutazione odierna, pubblicata (Proceedings of the National 

Academy of Sciences), dimostra una sottovalutazione del volume 

dell'encefalo: in realtà si tratta di 430 ml, cioé di un cervello 

che rientra perfettamente nei parametri della patologia della   
Sindrome di Down, per la zona geografica in esame. 

Anche il femore corto permise - estrapolando dalle altezze di pigmei africani di calcolare un'altezza ipotetica errata. In realtà i pz affetti da sindrome di Down hanno femori più corti del normale. un'altra caratteristica che fa propendere per la tesi della sindrome di Down è l'asimmetria craniofacciale, un'asimmetria destro-sinistra che è tipica della malattia (vedi seconda immagine, sotto).

Conclusione: L'Uomo Florensis non esiste, è una bufala scientifica. Nella realtà, si tratta dei resti di un malato di Sindrome di Down di 15000 anni fa: un reperto unico, interessante, ma non abbastanza per dichiaralo una nuova specie di uomo...

Flores bones show features of Down syndrome, 

not new

                   'hobbit' human 

In October 2004, excavation of fragmentary skeletal remains from the island of Flores in Indonesia yielded what was called "the most important find in human evolution for 100 years." Its discoverers dubbed the find Homo floresiensis, a name suggesting a previously unknown species of human. 

This figure compares the skull of LB1 to that of Liang Momer E, another skull from Flores,  dated in the range of 3,000 to 5,000 years ago

 [Credit: © Photograph of Liang Momer E skull  taken at Naturalis Biodiversity Center (Leiden, Netherlands). All Rights Reserved]

 Now detailed reanalysis by an international team of researchers including Robert B. Eckhardt, professor of developmental genetics and evolution at Penn State, Maciej Henneberg, professor of anatomy and pathology at the University of Adelaide, and Kenneth Hsü, a Chinese geologist and paleoclimatologist, suggests that the single specimen on which the new designation depends, known as LB1, does not represent a new species. 

Instead, it is the skeleton of a developmentally abnormal human and, according to the researchers, contains important features most consistent with a diagnosis of Down syndrome. 
"The skeletal sample from Liang Bua cave contains fragmentary remains of several individuals," Eckhardt said. "LB1 has the only skull and thighbones in the entire sample." No substantial new bone discoveries have been made in the cave since the finding of LB1. Initial descriptions of Homo floresiensis focused on LB1's unusual anatomical characteristics: a cranial volume reported as only 380 milliliters (23.2 cubic inches), suggesting a brain less than one third the size of an average modern human's and short thighbones, which were used to reconstruct a creature standing 1.06 meters (about 3.5 feet tall).

Although LB1 lived only 15,000 years ago, comparisons were made to earlier hominins, including Homo erectus and Australopithecus. 

Other traits were characterized as unique and therefore indicative of a new species. 
A thorough reexamination of the available evidence in the context of clinical studies, the researchers said, suggests a different explanation. 
The researchers report their findings in two papers published today (Aug. 4) in the Proceedings of the National Academy of Sciences. In the first place, they write, the original figures for cranial volume and stature are underestimates, "markedly lower than any later attempts to confirm them." Eckhardt, Henneberg, and other researchers have consistently found a cranial volume of about 430 milliliters (26.2 cubic inches). "The difference is significant, and the revised figure falls in the range predicted for a modern human with Down syndrome from the same geographic region," Eckhardt said. 

LB1 is shown in three different views to illustrate facial asymmetry. 

A is the actual specimen,  B is the right side doubled at the midline and mirrored, and C is the left side doubled  and mirrored. 

Differences in left and right side facial architectures are apparent,  and illustrate growth abnormalities of LB1 

[Credit: A, E. Indriati, B&C, D.W. Frayer] 

The original estimate of 3.5 feet for the creature's height was based on extrapolation combining the short thighbone with a formula derived from an African pygmy population. 

But humans with Down syndrome also have diagnostically short thighbones, Eckhardt said. 
Though these and other features are unusual, he acknowledged, "unusual does not equal unique. The originally reported traits are not so rare as to have required the invention of a new hominin species." 
Instead, the researchers build the case for an alternative diagnosis: that of Down syndrome, one of the most commonly occurring developmental disorders in modern humans. "When we first saw these bones, several of us immediately spotted a developmental disturbance," said Eckhardt, "but we did not assign a specific diagnosis because the bones were so fragmentary. Over the years, several lines of evidence have converged on Down syndrome." 

The first indicator is craniofacial asymmetry, a left-right mismatch of the skull that is characteristic of this and other disorders. 
Eckhardt and colleagues noted this asymmetry in LB1 as early as 2006, but it had not been reported by the excavating team and was later dismissed as a result of the skull's being long buried, he said. 
A previously unpublished measurement of LB1's occipital-frontal circumference -- the circumference of the skull taken roughly above the tops of the ears -- allowed the researchers to compare LB1 to clinical data routinely collected on patients with developmental disorders. 
Here too, the brain size they estimate is within the range expected for an Australomelanesian human with Down syndrome. 
LB1's short thighbones not only match the height reduction seen in Down syndrome, Eckhardt said, but when corrected statistically for normal growth, they would yield a stature of about 1.26 meters, or just over four feet, a figure matched by some humans now living on Flores and in surrounding regions. 
These and other Down-like characteristics, the researchers state, are present only in LB1, and not in the other Liang Bua skeletal remains, further evidence of LB1's abnormality. "This work is not presented in the form of a fanciful story, but to test a hypothesis: Are the skeletons from Liang Bua cave sufficiently unusual to require invention of a new human species?" Eckhardt said. 
"Our reanalysis shows that they are not. The less strained explanation is a developmental disorder. Here the signs point rather clearly to Down syndrome, which occurs in more than one per thousand human births around the world." Additional context is available on the authors' website at www.LiangBuaCave.org. 

Source: Pennsylvania State University 

[August 04, 2014]
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