Teoria sull'origine della vita

Paleontologist presents origin of life theory

It has baffled humans for millennia: how did life begin on planet Earth? Now, new research from a Texas Tech University paleontologist suggests it may have rained from the skies and started in the bowels of hell.

Meteorite bombardment left large craters that contained water and chemical building blocks
for life, which ultimately led to the first organisms [Credit: Texas Tech University]

Sankar Chatterjee, Horn Professor of Geosciences and curator of paleontology at The Museum of Texas Tech University believes he has found the answer by connecting theories on chemical evolution with evidence related to our planet’s early geology.

“This is bigger than finding any dinosaur,” Chatterjee said. “This is what we’ve all searched for – the Holy Grail of science.”

Thanks to regular and heavy comet and meteorite bombardment of Earth’s surface during its formative years 4 billion years ago, the large craters left behind not only contained water and the basic chemical building blocks for life, but also became the perfect crucible to concentrate and cook these chemicals to create the first simple organisms.

Crater basins may have been the crucible of life
[Credit: Texas Tech University]

He will present his findings Oct. 30 during the 125th Anniversary Annual Meeting of the Geological Society of America in Denver.

As well as discovering how ancient animals flew, Chatterjee discovered the Shiva Meteorite Crater, which was created by a 25-mile-wide meteorite that struck off the coast of India. This research concluded this giant meteorite wreaked havoc simultaneously with the Chicxulub meteorite strike near Mexico, finishing the dinosaurs 65 million years ago.

Ironically, Chatterjee’s latest research suggests meteorites can be givers of life as well as takers. He said that meteor and comet strikes likely brought the ingredients and created the right conditions for life on our planet. By studying three sites containing the world’s oldest fossils, he believes he knows how the first single-celled organisms formed in hydrothermal crater basins.

As the basins filled, volcanically driven geothermal vents heated the water and
created convection. The result was constant water movement, creating
a thick primordial soup [Credit: Texas Tech University]

“When the Earth formed some 4.5 billion years ago, it was a sterile planet inhospitable to living organisms,” Chatterjee said. “It was a seething cauldron of erupting volcanoes, raining meteors and hot, noxious gasses. One billion years later, it was a placid, watery planet teeming with microbial life – the ancestors to all living things.”
Recipe for Living

“For may years, the debate on the origins of life centered on the chemical evolution of living cells from organic molecules by natural processes. Chatterjee said life began in four steps of increasing complexity – cosmic, geological, chemical and biological.

Hierarchical Origin of Life: Historical Contingency Parsimony principle chooses
the simplest explanation for the origin of life [Credit: Texas Tech University]

In the cosmic stage, a still-forming Earth and our solar system took a daily pounding from rocky asteroids and icy comets between 4.1 to 3.8 billion years ago. Plate tectonics, wind and water have hidden evidence of this early onslaught on our planet, but ancient craters on the surfaces of Mars, Venus, Mercury and our moon show just how heavy the meteorite showers once were.

Larger meteorites that created impact basins of about 350 miles in diameter inadvertently became the perfect crucibles, he said. These meteorites also punched through the Earth’s crust, creating volcanically driven geothermal vents. Also, they brought the basic building blocks of life that could be concentrated and polymerized in the crater basins.

After studying the environments of the oldest fossil-containing rocks on Earth in Greenland, Australia and South Africa, Chatterjee said these could be remnants of ancient craters and may be the very spots where life began in deep, dark and hot environments.

Crater Basin with Hydrothermal Vent System Meteorites brought biomolecules
of cell membrane [Credit: Texas Tech University]

Because of Earth’s perfect proximity to the sun, the comets that crashed here melted into water and filled these basins with water and more ingredients. This gave rise to the geological stage. As these basins filled, geothermal venting heated the water and created convection, causing the water to move constantly and create a thick primordial soup.

“The geological stage provides special dark, hot, and isolated environments of the crater basins with the hydrothermal vent systems that served as incubators for life,” he said. “Segregation and concentration of organic molecules by convective currents took place here, something like the kinds we find on the ocean floor, but still very different. It was a bizarre and isolated world that would seem like a vision of hell with the foul smells of hydrogen sulfide, methane, nitric oxide and steam that provided life-sustaining energy.”

Then began the chemical stage, Chatterjee said. The heat churning the water inside the craters mixed chemicals together and caused simple compounds to grow into larger, more complex ones.
Protecting Important Information

Most likely, pores and crevices on the crater basins acted as scaffolds for concentrations of simple RNA and protein molecules, he said. Unlike a popular theory that believes RNA came first and proteins followed, Chatterjee believes RNA and proteins emerged simultaneously and were encapsulated and protected from the environment.

Endosymbiotic origin of Eukoryote cells
[Credit: Texas Tech University]

“The dual origin of the ‘RNA/protein’ world is more plausible in the vent environments than the popular ‘RNA world,’” he said. “RNA molecules are very unstable. In vent environments, they would decompose quickly. Some catalysts, such as simple proteins, were necessary for primitive RNA to replicate and metabolize. On the other hand, amino acids, from which proteins are made, are easier to make than RNA components.”

The question remains how loose RNA and protein material floating in this soup protected itself in a membrane. Chatterjee believes University of California professor David Deamer’s hypothesis that membranous material existed in the primordial soup. Deamer isolated fatty acid vesicles from the Murchison meteorite that fell in 1969 in Australia. The cosmic fatty bubbles extracted from the meteorite mimic cell membranes.

“Meteorites brought this fatty lipid material to early Earth,” Chatterjee said. “This fatty lipid material floated on top of the water surface of crater basins but moved to the bottom by convection currents. At some point in this process during the course of millions of years, this fatty membrane could have encapsulated simple RNA and proteins together like a soap bubble. The RNA and protein molecules begin interacting and communicating. Eventually RNA gave way to DNA – a much more stable compound – and with the development of the genetic code, the first cells divided.”

Fossilized early life [Credit: Texas Tech University]

The final stage – the biological stage – represents the origin of replicating cells as they began to store, process and transmit genetic information to their daughter cells, Chatterjee said. Infinite combinations took place, and countless numbers must have failed to function before the secret of replication was broken and the proper selection occurred.

“These self-sustaining first cells were capable of Darwinian evolution,” he said. “The emergence of the first cells on the early Earth was the culmination of a long history of prior chemical, geological and cosmic processes.”

Chatterjee also believes that modern RNA-viruses and protein-rich prions that cause deadly diseases probably represent the evolutionary legacy of primitive RNA and protein molecules. They may be the oldest cellular particles that predated the first cellular life. Once cellular life evolved, RNA-viruses and prions became redundant, but survived as parasites on the living cells.

The problem with theories on the origins of life is that they don’t propose any experiments that lead to the emergence of cells, Chatterjee said. However, he suggested an experiment to recreate the ancient prebiotic world and support or refute his theory.

“If future experiments with membrane-bound RNA viruses and prions result in the creation of a synthetic protocell, it may reflect the plausible pathways for the emergence of life on early Earth,” he said.
Author: John Davis | Source: Texas Tech University [October 29, 2013]

tatuaggio terapeutico

Ötzi the iceman's tattoos may be an early form of 'acupuncture'

Tattoos are traditionally used to decorate the skin, but now archaeologists believe skin etchings discovered on a 5,000-year-old mummy could have been intended as therapy.

The leathery remains of Otzi the iceman, the Stone Age hunter who emerged from a melting alpine glacier after 5,000 years [Credit: South Tyrol Museum of Archaeology]

The marks found on Ötzi the iceman reveal that tattoos could have been used as a primitive form of acupuncture.

The iceman's tattoos are largely seen on the parts of his body that endured wear-and-tear, causing archaeologists to liken the practice of tattooing to acupuncture, which is itself an ancient treatment for joint distress.

Ötzi's body art is the only known example of real-life ancient tattoos and reveal how the marks were made in Copper Age Europe.

The ice man's tattoos are largely seen on parts of the body that endured wear-and-tear, causing archaeologists to like the practice to acupuncture, which is itself an ancient treatment for joint distress. Radiological images of the tattooed areas of the mummy show degenerative areas under the tattoos that could have caused pain [Credit: South Tyrol Museum of Archaeology]

Writing in the publication Archaeology, U.S. experts Jarrett A. Lobell and Eric A. Powell said Ötzi's body, which was almost perfectly preserved in ice, provides unique evidence of early medicine for archaeologists.

They said Ötzi got his 50 tattoos - most of which are lines and crosses - by enduring a series of small incisions in his skin, which were then rubbed with charcoal to make the marks.

'Because they are all found on parts of the body that show evidence of a lifetime of wear and tear - the ankles, wrists, knees, Achilles tendon, and lower back, for example - it’s thought that Ötzi’s tattoos were therapeutic, not decorative or symbolic,' they added.

Ötzi's tattoos are the only known examples of real-life ancient tattoos as all other examples are found in artwork at the time and reveal how the marks were made in Copper Age EuropeOtzi Iceman Tattoo [Credit: South Tyrol Museum of Archaeology]

When the mummy was first studied, experts were shocked at Ötzi's tattooed skin as they had never seen real examples of Copper Age tattoos before.

They were also surprised as it is popularly thought that acupuncture was invented more than 2,000 years later in Asia and the mummy's markings look like they have been made over joints under stress such as the ankles and wrists.

They wrote: 'Of course we can't be absolutely sure why these tattoos were placed in those locations. It's possible Ötzi's people believed those regions of the body were spiritually significant. Still, it's very possible that this was an early effort at acupuncture.'

Most of Otzi's tattoos are lines (pictured) and crosses found on major joints of his body. The mummy is specially illuminated here to show the tattoos clearly [Credit: South Tyrol Museum of Archaeology]

If this is the case, it would appear that the tattoos were not originally intended to be merely decorative or symbolic, but could have been used as a kind of medicine to treat ailments like rheumatism, and arthritis, which are also treated using acupuncture.

A spokesman for the South Tyrol Museum of Archaeology, told Mail Online:' It seems common opinion that the Iceman tattoos are not ornamental but therapeutic tattoos for pain relief.

'Radiological images of the tattooed areas show degenerative areas under the tattoos that could have caused pain. As the tattooing spots lie approximately over the acupuncture medians, it seems common opinion that they could have been use for that.'

It would appear that the tattoos were not originally intended to be merely decorative or symbolic, but could have been sued as a kind of medicine to treat ailments like rheumatism, and arthritis, which are also treated using acupuncture [Credit: South Tyrol Museum of Archaeology]

Professor Frank Rühli, head of the Centre for Evolutionary Medicine at the University of Zurich, told Mail Online the tattoos were probably a combination of decorative art and therapy.

He said that while there might be a connection to suggest the tattoos functioned as a form of ancient acupuncture, it is difficult to see which ailments the mummy suffered from, so an indication of the marks being therapeutic is 'likely' but cannot be proven as there are not a number of similar bodies to study, found in the same location that are the same age.

The spokesman for the South Tyrol Museum of Archaeology said that if indeed the tattoos were created as a form of acupuncture, 'people of the Iceman's times would have known not only about nature around them, but also about the human body and its reactions - I think this is remarkable.'

While the reasons for creating the tattoos may not be agreed upon, archaeologists believe that judging by the clothing, tools and weapons found with the mummy frozen in the Alps on the Austrian, Italian border two decades ago, Ötzi was a herder or a chieftain in Copper Age Europe.

Author: Sarah Griffiths | Source: Daily Mail [October 28, 2013]

INGANNARE. E' FACILE.

Sulla Rete c'è tutto.
Tutte le fesserie che si desidera scrivere. Tutto il copia-incolla incontrollato. Tutte le informazione tendenziose, strumentali, malevole o inventate.
Tutto: talvolta, persino la verità...
C'è qualcuno che - ormai da tempo - è salito sullo sgabello, si è messo il cappio al collo ed ha già dato la prima stretta alla corda, per quanto riguarda la propria credibilità scientifica.
Non c'è più bisogno di prenderlo in giro, insomma: ormai si prende in giro da sé.

Ma è fastidiosamente facile scrivere fesserie ed essere creduti.

Per dimostrare questo ho pubblicato su questo blog un post su un misterioso 'manufatto' d'argento mostratomi da un presunto tombarolo sardo.
Non c'era niente di vero!
La foto del 'manufatto' è presa dalla voce 'Palladio' su WIKIPEDIA e si tratta - appunto - di un campione di palladio.
Le altre due foto sono reali reperti archeologici, per dare maggior credito e dignità alla panzana. 
E' questo il metodo usato da tutti i falsari: mescolare abilmente 'palladio' e verità. 

Speravo di non essere creduto, o - almeno - di ricevere qualche risposta perplessa e dubbiosa. Non è stato così.
Ingannare è facile.

Il lato peggiore del manufatto:  una creatura mostruosa (metà 'cavallo' e metà pesce o serpente di mare), cavalcata da un personaggio minuscolo indecifrabile e condotta da un 'auriga' chinato sul suo dorso, tutti trainano un carro alato che accoglie un personaggio di aspetto regale, probabilmente una divinità. 

È stato rinvenuto, in una regione non meglio specificata della Sardegna centrale, un manufatto d’argento plumbeo raffigurante una divinità su un carro alato in corsa. Il fatto è avvenuto per caso – dopo un abbondante acquazzone di una settimana fa – in un campo presso una zona archeologica non transennata.

So che la galena era ed è tuttora presente in discreta quantità in Sardegna.

Un mio conoscente mi ha mostrato frettolosamente varie fotografie del reperto, che – mi assicura – non è in mano sua, bensì custodito dalla persona che lo avrebbe scavato nottetempo e con grande rischio personale “in una zona archeologica sicuramente nuragica” ben nota da anni anche agli archeologi, che però non avrebbero completato i propri scavi ufficiali, né i lavori di consolidamento del nuraghe del sito.

Al mio conoscente –  iniziali V. C., persona non colta, ma di vivace curiosità – è noto solamente il soprannome di questo personaggio  – che non esito a definire ‘tombarolo’ – che si farebbe chiamare ‘Murena’ da alcuni, ma che sarebbe noto anche con molti altri soprannomi , sempre pronti all’occorrenza.

Gli ho chiesto di lasciarmi pubblicare tutte le fotografie che mi aveva mostrato (circa 20), ma si è subito molto inquietato ed infine, solo dopo molte mie insistenze e preghiere,  si è deciso a lasciarmene pubblicare solamente una: quella senza riferimenti centimetrici e senza sfondi, o altri elementi utili (le mani di chi tiene l’oggetto, per esempio) dai quali si possa risalire in qualche modo allo scavatore, o alla zona.

L’oggetto – di circa 7- 8 cm di lunghezza – rappresenta un personaggio di rango, incoronato, che siede al centro di un cocchio alato, rappresentato in modo molto sintetico. Davanti a lui sono un cavallo mostruoso con coda di pesce che traina il cocchio fatato, il cocchiere , in posa contratta come un fantino ed un più piccolo personaggio seduto sulla groppa del ‘cavallo’.

Ora, è noto che sono state riprodotte varie rappresentazioni di Yahweh (transillterato come Giove), per esempio su monete orientali. 

Dracma persiana detta YHD, risalente al IV secolo a.C. e probabilmente coniata per una regione Giudaica. In particolare è da segnalarsi il cocchio alato, quasi solo simbolico, oltre a tutti gli altri attributi della divinità, che circondano l'effige del dio.

Esistono varie dracme d’argento yhd , probabilmente come quella che mostro in figura: una moneta d’argento  coniata dalla amministrazione Persiana  (risalente al IV secolo a.C.) in una zona Giudaica. Tali raffigurazioni – seppure tardive – rappresentano per l’appunto questo medesimo personaggio divino, su cocchio alato. Per tale motivo trovo molto curioso e suggestivo che una rappresentazione del tutto sovrapponibile sia stata trovata da un ‘Murena’ qualunque – descrittomi come mai uscito fisicamente dalla Sardegna e del tutto illetterato – in una zona della Sardegna centrale.

La moneta mostra una divinità seduta su di un carro alato con ruote, qualche volta interpretato come Yahweh (Yahu).

Il rendimento fonetico poteva essere tanto “YHD” (Giudea) quanto “YHW” (Yahu).

La fotografia che mi è stato permesso pubblicare, purtroppo, è quella meno significativa di tutte. Infatti, sul lato che la ‘mia’ foto non permette di vedere, c’è anche quella che sembrerebbe proprio essere una scritta.

Questa 'manina' è sita sotto alla scritta: "Benedetto da Yahweh e dalla sua asherah” e si trova sulla parete di una tomba dell'età del ferro presso Hebron (Khirbet el-Kohm). 

Ho cercato affannosamente nell’iconografia in mio possesso ed in quella reperibile in Rete, ma la cosa più simile che ho trovato è quella che posto (non è quella del manufatto, sia ben chiaro, ma le assomiglia molto: una specie di ‘manina’ incassata nel metallo, schematica e rigida, con cinque dita).

Non so azzardare ipotesi né riferire di altri eventuali segni, perché la cosa si è svolta tutta nell’arco di solo 7-10 minuti disordinati e confusi e non ho avuto il tempo di riordinare le mie poche idee.

Temo, però,  che il pezzo andrà smarrito nei meandri nascosti e complicati del mercato clandestino di reperti.  Il mio conoscente, per la verità, non ha affatto parlato di prezzi.

Alla fine di tutto, mi sono anche domandato perché mai mi abbia messo a parte della faccenda. Credo che potrebbe essere un meccanismo per ‘farsi pubblicità’ in qualche modo, in modo da creare attesa tra i possibili compratori.