The elongated body of some present-day fish evolved in different ways. Paleontologists from the University of Zurich have now discovered a new mode of body elongation based on a discovery in an exceptionally preserved fossilfish from Southern Ticino. In Saurichthys curionii, an early ray-finned fish, the vertebral arches of the axial skeleton doubled, resulting in the elongation of its body and giving it a needlefish-like appearance. The 240-million-year-old fossil find from Switzerland also revealed that this primitive fish was not as flexible as today’s eels, nor could it swim as fast or untiringly as a tuna.

Snake and eel bodies are elongated, slender and flexible in all three dimensions. This striking body plan has evolved many times independently in the more than 500 million years of vertebrate animals history. Based on the current state of knowledge, the extreme elongation of the body axis occurred in one of two ways: either through the elongation of the individual vertebrae of the vertebral column, which thus became longer, or through the development of additional vertebrae and associated muscle segments.
Long body thanks to doubling of the vertebral arches

A team of paleontologists from the University of Zurich headed by Professor Marcelo Sánchez-Villagra now reveal that a third, previously unknown mechanism of axial skeleton elongation characterized the early evolution of fishes, as shown by an exceptionally preserved form. Unlike other known fish with elongate bodies, the vertebral column of Saurichthys curionii does not have one vertebral arch per myomeric segment, but two, which is unique. This resulted in an elongation of the body and gave it an overall elongate appearance. “This evolutionary pattern for body elongation is new,” explains Erin Maxwell, a postdoc from Sánchez-Villagra’s group. “Previously, we only knew about an increase in the number of vertebrae and muscle segments or the elongation of the individual vertebrae.”

The fossils studied come from the Monte San Giorgio find in Ticino, which was declared a world heritage site by UNESCO in 2003. The researchers owe their findings to the fortunate circumstance that not only skeletal parts but also the tendons and tendon attachments surrounding the muscles of the primitive predatory fish had survived intact. Due to the shape and arrangement of the preserved tendons, the scientists are also able to draw conclusions as to the flexibility and swimming ability of the fossilized fish genus. According to Maxwell, Saurichthys curionii was certainly not as flexible as today’s eels and, unlike modern oceanic fishes such as tuna, was probably unable to swim for long distances at high speed. Based upon its appearance and lifestyle, the roughly half-meter-long fish is most comparable to the garfish or needlefish that exist today.
Literature:

Erin E. Maxwell, Heinz Furrer, Marcelo R. Sánchez-Villagra. Exceptional fossil preservation demonstrates a new mode of axial skeleton elongation in early ray-finned fishes. Nature Communications, October 7, 2013. doi: 10.1038/ncomms3570

FOTO CON DIDASCALIA CHE MERITA SU

http://www.mediadesk.uzh.ch/articles/2013/neues-evolutionsmuster-fuer-lang-gestreckte-fische_en.html

Paleoanthropologists from the University of Zurich have uncovered the intact skull of an early Homo individual in Dmanisi, Georgia. This find is forcing a change in perspective in the field of paleoanthropology: human species diversity two million years ago was much smaller than presumed thus far. However, diversity within the «Homo erectus», the first global species of human, was as great as in humans today.

This is the best-preserved fossil find yet from the early era of our genus. The particularly interesting aspect is that it displays a combination of features that were unknown to us before the find. The skull, found in Dmanisi by anthropologists from the University of Zurich as part of a collaboration with colleagues in Georgia funded by the Swiss National Science Foundation, has the largest face, the most massively built jaw and teeth and the smallest brain within the Dmanisi group.

It is the fifth skull to be discovered in Dmanisi. Previously, four equally well-preserved hominid skulls as well as some skeletal parts had been found there. Taken as a whole, the finds show that the first representatives of the genus Homo began to expand from Africa through Eurasia as far back as 1.85 million years ago.
Diversity within a species instead of species diversity

Because the skull is completely intact, it can provide answers to various questions which up until now had offered broad scope for speculation. These relate to none less than the evolutionary beginning of the genus «Homo» in Africa around two million years ago at the beginning of the Ice Age, also referred to as the Pleistocene. Were there several specialized «Homo» species in Africa at the time, at least one of which was able to spread outside of Africa too? Or was there just one single species that was able to cope with a variety of ecosystems? Although the early Homo finds in Africa demonstrate large variation, it has not been possible to decide on answers to these questions in the past. One reason for this relates to the fossils available, as Christoph Zollikofer, anthropologist at the University of Zurich, explains: «Most of these fossils represent single fragmentary finds from multiple points in space and geological time of at least 500,000 years. This ultimately makes it difficult to recognize variation among species in the African fossils as opposed to variation within species».
As many species as there are researchers

Marcia Ponce de León, who is also an anthropologist at the University of Zurich, points out another reason: paleoanthropologists often tacitly assumed that the fossil they had just found was representative for the species, i.e. that it aptly demonstrated the characteristics of the species. Statistically this is not very likely, she says, but nevertheless there were researchers who proposed up to five contemporary species of early «Homo» in Africa, including «Homo habilis», «Homo rudolfensis», «Homo ergaster» and «Homo erectus». Ponce de León sums up the problem as follows: «At present there are as many subdivisions between species as there are researchers examining this problem».
Tracking development of «Homo erectus» over one million years thanks to a change in perspective

Dmanisi now offers the key to the solution. According to Zollikofer, the reason why Skull 5 is so important is that it unites features that have been used previously as an argument for defining different African «species». In other words: «Had the braincase and the face of the Dmanisi sample been found as separate fossils, they very probably would have been attributed to two different species». Ponce de León adds: «It is also decisive that we have five well-preserved individuals in Dmanisi whom we know to have lived in the same place and at the same time». These unique circumstances of the find make it possible to compare variation in Dmanisi with variation in modern human and chimpanzee populations. Zollikofer summarizes the result of the statistical analyses as follows: «Firstly, the Dmanisi individuals all belong to a population of a single early Homo species. Secondly, the five Dmanisi individuals are conspicuously different from each other, but not more different than any five modern human individuals, or five chimpanzee individuals from a given population».

Diversity within a species is thus the rule rather than the exception. The present findings are supported by an additional study recently published in the PNAS journal. In that study, Ponce de León, Zollikofer and further colleagues show that differences in jaw morphology between the Dmanisi individuals are mostly due to differences in dental wear.

This shows the need for a change in perspective: the African fossils from around 1.8 million years ago likely represent representatives from one and the same species, best described as «Homo erectus». This would suggest that «Homo erectus» evolved about 2 million years ago in Africa, and soon expanded through Eurasia – via places such as Dmanisi – as far as China and Java, where it is first documented from about 1.2 million years ago. Comparing diversity patterns in Africa, Eurasia and East Asia provides clues on the population biology of this first global human species.

This makes «Homo erectus» the first «global player» in human evolution. Its redefinition now provides an opportunity to track this fossil human species over a time span of 1 million years.
Literature:

David Lordkipanidze, Marcia S. Ponce de León, Ann Margvelashvili, Yoel Rak, G. Philip Rightmire, Abesalom Vekua, and Christoph P.E. Zollikofer. A complete skull from Dmanisi, Georgia, and the evolutionary biology of early Homo. Science. October 18, 2013. doi: 10.1126/science.1238484

Ann Margvelashvili, Christoph P. E. Zollikofer, David Lordkipanidze, Timo Peltomäki, Marcia S. Ponce de León. Tooth wear and dentoalveolar remodeling are key factors of morphological variation in the Dmanisi mandibles. Proceedings of the National Academy of Sciences of the United States of America (PNAS). September 2, 2013. doi: 10.1073/pnas.1316052110

Research and development collaborative work with huge leverage

The new research findings on Dmanisi are based on collaborative work ongoing for many years between the Anthropological Institute at the University of Zurich and the Georgian National Museum in Tbilisi. The Dmanisi project is financed by SCOPES (Scientific co-operation between Eastern Europe and Switzerland), a research program co-funded by the Swiss National Science Foundation (SNSF) and the Swiss Agency for Development and Co-operation (SDC). This research tool operates with a comparatively modest budget, but has a major and positive impact on the research landscape in the participating countries.

CI SONO MOLTE FOTO INTERESSANTI LE METTI TU?

http://www.mediadesk.uzh.ch/articles/2013/schaedelfund-dmanisi_en.html

Scaring away sharks in AU using recorded sounds of orcas - a theory to be tested but there's concern that it could chase away other animals, upsetting the marine balance.

'Screams' could chase away other marine life
by: Mitchell Nadin
From: The Australian
November 05, 2013 12:00AM

RECORDINGS of killer whale "screams" intended to scare sharks from popular West Australian beaches could end up chasing away other marine life, including dolphins.
http://www.theaustralian.com.au/news/health-science/screams-could-chase-away-other-marine-life/story-e6frg8y6-1226753085502#!

L’astronauta Luca Parmitano è atterrato nella notte dell’11 novembre alle 3:50 a bordo della capsula Soyuz, nelle steppe del Kazakistan.

È giunta al termine la missione da record dell'Agenzia Spaziale Italiana che avuto come protagonista Luca Parmitano, astronauta italiano dell'Agenzia Spaziale Europea e maggiore dell'Aeronautica Militare. Dopo quasi sei mesi sulla Stazione Spaziale Internazionale, oltre 30 esperimenti, due attività extra veicolari e l'attracco di tre navicelle, Luca Parmitano è tornato sulla Terra insieme all'astronauta della NASA Karen Nyberg e al comandante, il cosmonauta Fyodor Yurchikhin.

Sganciandosi dalla Stazione ieri sera, il viaggio di rientro attraverso l'atmosfera è stato brevissimo: l'equipaggio ha ridotto la propria velocità di crociera da 28.800 Km/h in orbita, a zero, nel corso di poco più di tre ore, ed è arrivato a destinazione nelle steppe del Kazakistan.

Secondo un recente studio, 1,1 milioni di persone nella Repubblica Centrafricana rischiano la fame mentre la situazione potrebbe peggiorare a causa dei raccolti ridotti e di una drastica riduzione delle attività economiche a seguito di mesi di violenze nel paese.

Una missione di verifica della sicurezza alimentare d’emergenza, condotta congiuntamente dalle Nazioni Unite, dalle organizzazioni non-governative e dal governo della Repubblica Centrafricana, riporta come 1,1 milioni di persone, circa il 30 per cento della popolazione che vive fuori della capitale Bangui, sia impossibilitato a sfamarsi in maniera regolare o necessiti di assistenza alimentare.

Almeno la metà degli stimati 395.000 sfollati nella Repubblica Centrafricana non ha accesso ad una quantità sufficiente di cibo sano e nutriente, necessario per condurre una vita attiva e in salute.

L’asteroide Vesta non è solo uno dei corpi più antichi del nostro Sistema solare, ma ci sta rivelando che la sua storia evolutiva è molto più complessa di quanto si ritenesse finora. L’ultimo studio sul corpo celeste appena pubblicato sulla rivista Nature,  realizzato grazie ai dati raccolti dallo spettrometro italiano VIR (Visual and InfraRed spectrometer) a bordo della sonda Dawn della NASA  indica infatti che l’olivina, un minerale presente nelle regioni più interne dei pianeti rocciosi come la Terra, risulta quasi del tutto assente nei grandi bacini meridionali di Vesta, che si pensa si siano formati a seguito di impatti con altri corpi celesti e che avrebbero asportato gli strati più esterni della crosta ed esposto il suo mantello. L’olivina è stata invece osservata,  sorprendentemente, in grande abbondanza in una  regione lontana dai bacini sud, nell’emisfero nord.

L’apprezzamento delle opere d’arte figurative aumenta dopo la stimolazione elettrica anodica a bassa intensità della corteccia dorso laterale prefrontale sinistra. Lo rivela uno studio dell’Università di Milano-Bicocca appena pubblicato sulla rivista Social Cognitive and Affective Neuroscience.

Milano, 4 novembre 2013 – Il grado di apprezzamento di un’opera d’arte può aumentare a seguito di una stimolazione elettrica a bassa intensità della corteccia dorso laterale prefrontale sinistra, sede della valutazione estetica. È la conclusione alla quale sono arrivati i ricercatori dell’Università di Milano-Bicocca che hanno pubblicato uno studio sulla rivista Social Cognitive and Affective Neuroscience.

Lo studio (The world can look better: enhancing beauty experience with brain stimulation doi:10.1093/scan/nst165) coordinato da Zaira Cattaneo, ricercatore di Psicobiologia e Psicologia Fisiologica nel dipartimento di Psicologia dell’Università di Milano-Bicocca e presso il Brain Connectivity Center-IRCCS Mondino di Pavia e realizzato con il contributo di Carlotta Lega, dottoranda in Psicologia presso l’ateneo milanese, Albert Flexas, Enric Munar, Camilo J. Cela-Conde dell’Università delle Isole Baleari e Marcos Nadal dell’Università di Vienna, rientra nel campo della neuro estetica, branca delle neuroscienze che si occupa di studiare i correlati neurali alla base dell'apprezzamento estetico.

Si è appena conclusa la prima campagna di ricerche sul paleolitico della Valle dello Zarqa, condotta dall’Istituto Italiano di Paleontologia Umana insieme alla Universidade de Sao Paulo (Brasile) e alla Hashemite University di Zarqa (Giordania). L’obbiettivo è quello di datare i siti archeologici paleolitici scoperti negli anni ’90 dalla missione dell’Università di Roma coordinanata da Gaetano Palumbo. A quel tempo vennero trovati numerosi giacimenti del Pleistocene inferiore e medio, con grandi quantità di industrie litiche di modo 1 e 2. Una prima attribuzione cronologica, basata sui dati archeologici e biostratigrafici attribuiva al giacimento più antico un’età di un milione di anni.

Progetto MIUR Diffusione Cultura (legge 6/2000)

Il progetto finanziato dal MIUR prevede nella sua parte “fisica” l’allestimento di uno spazio espositivo presso il Laboratorio dell’Istituto Italiano di Paleontologia Umana ad Anagni in cui verranno presentati alcuni dei più importanti reperti paleontologici e archeologici pleistocenici rinvenuti nel Bacino.

Inoltre i visitatori potranno osservare da vicino l’attività dei paleontologi e archeologi durante le fasi di catalogazione e studio dei reperti. I ricercatori illustreranno le tecniche di scavo con l’allestimento di un Laboratorio di attività “simulate” dove verranno mostrate “le tecniche e gli strumenti del mestiere”. In questo modo i visitatori avranno la possibilità di seguire le metodologie di indagine degli studiosi dalla parte della “scoperta” fino allo studio e valorizzazione. Saranno organizzate delle attività divulgative anche in situ durante le operazioni di survey da parte dei ricercatori.

Si sono conclusi il 22 settembre 2013 gli scavi dell’Istituto Italiano di Paleontologia Umana nel sito pleistocenico di Coste San Giacomo (Anagni) coodiretti da Fabio Parenti e Raffaele Sardella. Nel corso dello scavo, condotto in collaborazione con il  Dipartimento di Scienze della Terra della Sapienza – Università di Roma, sono venuti in luce  numerosissimi fossili di grandi e piccoli mammiferi di circa due milioni di anni fa. Fra essi spiccano per importanza  paleontologica due diverse specie di proboscidati, tre specie di cervi, gazzelle, ippopotami, carnivori come la tigre dai denti a sciabola e iene e, per la prima volta in Europa mediterranea, il lupo etrusco.