Frank Tipler desce o cacete na Nomenklatura científica: a diferença entre a ' verdadeira ciência' e a ciência 'Cargo cult'

sábado, julho 31, 2010

The Difference between ‘True Science’ and ‘Cargo-Cult Science’
“Science is the belief in the ignorance of experts” is how the great Nobel Prize-winning physicist Richard Feynman defined science.
July 27, 2010 - by Frank J. Tipler

“Science is the belief in the ignorance of experts” is how the great Nobel Prize-winning physicist Richard Feynman defined science in his article “What is Science?” Feynman emphasized this definition by repeating it in a stand-alone sentence in extra large typeface in his article.  (Feynman’s essay is available online, but behind a subscription wall: The Physics Teacher (1969) volume 7, starting page 313.)
Immediately after his definition of science, Feynman wrote: “When someone says, ‘Science teaches such and such,’ he is using the word incorrectly. Science doesn’t teach anything; experience teaches it. If they say to you, ‘Science has shown such and such,’ you should ask, ‘How does science show it? How did the scientists find out? How? What? Where?’ It should not be ‘science has shown.’ And you have as much right as anyone else, upon hearing about the experiments (but be patient and listen to all the evidence) to judge whether a sensible conclusion has been arrived at.”
And I say, Amen. Notice that “you” is the average person. You have the right to hear the evidence, and you have the right to judge whether the evidence supports the conclusion. We now use the phrase “scientific consensus,” or “peer review,” rather than “science has shown.” By whatever name, the idea is balderdash. Feynman was absolutely correct.
When the attorney general of Virginia sued to force Michael Mann of “hockey stick” fame to provide the raw data he used, and the complete computer program used to analyze the data, so that “you” could decide, the Faculty Senate of the University of Virginia (where Mann was a professor at the time he defended the hockey stick) declared this request — Feynman’s request — to be an outrage. You peons, the Faculty Senate decreed, must simply accept the conclusions of any “scientific endeavor that has satisfied peer review standards.” Feynman’s — and the attorney general’s and my own and other scientists’ — request for the raw data, so we can “judge whether a sensible conclusion has been arrived at,” would, according to the Faculty Senate, “send a chilling message to scientists … and indeed scholars in any discipline.”
According the Faculty Senate of the University of Virginia, “science,” and indeed “scholarship” in general, is no longer an attempt to establish truth by replicable experiment, or by looking at evidence that can be checked by anyone. “Truth” is now to be established by the decree of powerful authority, by “peer review.” Wasn’t the whole point of the Enlightenment to avoid exactly this?
...
Read more here: Pajamas Media
+++++
NOTA CAUSTICANTE DESTE BLOGGER:
Este blogger há muito vem denunciando o comportamento dos revisores como guardas-cancelas impedindo a divulgação de novas ideias e teorias científicas, bem como evitando com unhas e dentes quaisquer críticas às teorias darling da Akademia, especialmente as que dizem respeito às origens e evolução do universo e da vida. É preciso acabar com esse patrulhamento ideológico que impede o avanço da ciência.
Eu sei do que estou falando…


++++

Vote neste blog para o prêmio TOPBLOG.

Moh Ushiv - Mordechai Ben David


+++++
Para, por e com Israel, sempre!
+++++
Vote neste blog para o prêmio TOPBLOG.

Novos modelos cosmológicos sem o Big Bang: sem princípio e sem fim





Cosmological Models with No Big Bang 

Wun-Yi Shu 

(Submitted on 11 Jul 2010) 

In the late 1990s, observations of Type Ia supernovae led to the astounding discovery that the universe is expanding at an accelerating rate. The explanation of this anomalous acceleration has been one of the great problems in physics since that discovery. In this article we propose cosmological models that can explain the cosmic acceleration without introducing a cosmological constant into the standard Einstein field equation, negating the necessity for the existence of dark energy. There are four distinguishing features of these models: 1) the speed of light and the gravitational "constant" are not constant, but vary with the evolution of the universe, 2) time has no beginning and no end, 3) the spatial section of the universe is a 3-sphere, and 4) the universe experiences phases of both acceleration and deceleration. One of these models is selected and tested against current cosmological observations of Type Ia supernovae, and is found to fit the redshift-luminosity distance data quite well. 

Comments: 33 pages, 3 figures 
Subjects: General Physics (physics.gen-ph) 
Cite as: arXiv:1007.1750v1 [physics.gen-ph] 
Submission history 
From: Wun-Yi Shu [view email] 
[v1] Sun, 11 Jul 2010 00:00:49 GMT (322kb)

FREE PDF GRÁTIS arXiv


+++++


Vote neste blog para o prêmio TOPBLOG.

Elokai - Dudu Fisher na Sinagoga da Cracóvia - Polônia



+++++


Para, por e com Israel, sempre!


+++++
Vote neste blog para o prêmio TOPBLOG.

Shuvi - 1981

sexta-feira, julho 30, 2010



+++++

Lyrics:

שׁוּבִי נַפְשִׁי לִמְנוּחָיְכִי כִּי יי גָּמַל עָלָיְכִי
הֶאֱמַנְתִּי כִּי אֲדַבֵּר אֲנִי עָנִיתִי מְאֹד
אֲנִי אָמַרְתִּי בְחָפְזִי כָּל הָאָדָם כֹּזֵב
(Tehilim, Kapitel 116)

Composed by: Baruch Menzlefsky A"H
Soloist: Unidentified followed by Shloime Dachs and Avraham Fried.



+++++


Source/Fonte: Gruntig.net

+++++

Vote neste blog para o prêmio TOPBLOG 2010.
+++++

Para, por e com Israel, sempre!


Kol sason Itzik Dadya - קול ששון-איציק דדיה




+++++


Para, por e com Israel, sempre!


+++++


Vote neste blog para o prêmio TOPBLOG 2010.

Neuroanatomia escondida na pintura 'Separação da Luz das Trevas' de Michelangelo na Capela Sistina

Neurosurgery: 

May 2010 - Volume 66 - Issue 5 - p 851–861 

doi: 10.1227/01.NEU.0000368101.34523.E1 

Legacy-Institutions and People: Editor's Choice 


Concealed Neuroanatomy in Michelangelo's Separation of Light From Darkness in the Sistine Chapel 

Suk, Ian BSc, BMC; Tamargo, Rafael J. MD, FACS 

Abstract 

Michelangelo Buonarroti (1475–1564) was a master anatomist as well as an artistic genius. He dissected cadavers numerous times and developed a profound understanding of human anatomy. From 1508 to 1512, Michelangelo painted the ceiling of the Sistine Chapel in Rome. His Sistine Chapel frescoes are considered one of the monumental achievements of Renaissance art. In the winter of 1511, Michelangelo entered the final stages of the Sistine Chapel project and painted 4 frescoes along the longitudinal apex of the vault, which completed a series of 9 central panels depicting scenes from the Book of Genesis. 


Source/Fonte: Image courtesy of Neurosurgery


It is reported that Michelangelo concealed an image of the brain in the first of these last 4 panels, namely, the Creation of Adam. Here we present evidence that he concealed another neuronanatomic structure in the final panel of this series, theSeparation of Light From Darkness, specifically a ventral view of the brainstem. The Separation of Light From Darkness is an important panel in the Sistine Chapel iconography because it depicts the beginning of Creation and is located directly above the altar. We propose that Michelangelo, a deeply religious man and an accomplished anatomist, intended to enhance the meaning of this iconographically critical panel and possibly document his anatomic accomplishments by concealing this sophisticated neuroanatomic rendering within the image of God. 

Copyright © by the Congress of Neurological Surgeons 


+++++

Vote neste blog para o prêmio TOPBLOG 2010.

A maioria das cópias de "matéria escura" está associada com genes conhecidos: o ENCODE pisou na bola?

Most “Dark Matter” Transcripts Are Associated With Known Genes 

Harm van Bakel1, Corey Nislow1,2, Benjamin J. Blencowe1,2, Timothy R. Hughes1,2* 

1 Banting and Best Department of Medical Research, University of Toronto, Toronto, Ontario, Canada, 2 Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada 

Abstract 

A series of reports over the last few years have indicated that a much larger portion of the mammalian genome is transcribed than can be accounted for by currently annotated genes, but the quantity and nature of these additional transcripts remains unclear. Here, we have used data from single- and paired-end RNA-Seq and tiling arrays to assess the quantity and composition of transcripts in PolyA+ RNA from human and mouse tissues. Relative to tiling arrays, RNA-Seq identifies many fewer transcribed regions (“seqfrags”) outside known exons and ncRNAs. Most nonexonic seqfrags are in introns, raising the possibility that they are fragments of pre-mRNAs. The chromosomal locations of the majority of intergenic seqfrags in RNA-Seq data are near known genes, consistent with alternative cleavage and polyadenylation site usage, promoter- and terminator-associated transcripts, or new alternative exons; indeed, reads that bridge splice sites identified 4,544 new exons, affecting 3,554 genes. Most of the remaining seqfrags correspond to either single reads that display characteristics of random sampling from a low-level background or several thousand small transcripts (median length = 111 bp) present at higher levels, which also tend to display sequence conservation and originate from regions with open chromatin. We conclude that, while there are bona fide new intergenic transcripts, their number and abundance is generally low in comparison to known exons, and the genome is not as pervasively transcribed as previously reported. 

Author Summary 

The human genome was sequenced a decade ago, but its exact gene composition remains a subject of debate. The number of protein-coding genes is much lower than initially expected, and the number of distinct transcripts is much larger than the number of protein-coding genes. Moreover, the proportion of the genome that is transcribed in any given cell type remains an open question: results from “tiling” microarray analyses suggest that transcription is pervasive and that most of the genome is transcribed, whereas new deep sequencing-based methods suggest that most transcripts originate from known genes. We have addressed this discrepancy by comparing samples from the same tissues using both technologies. Our analyses indicate that RNA sequencing appears more reliable for transcripts with low expression levels, that most transcripts correspond to known genes or are near known genes, and that many transcripts may represent new exons or aberrant products of the transcription process. We also identify several thousand small transcripts that map outside known genes; their sequences are often conserved and are often encoded in regions of open chromatin. We propose that most of these transcripts may be by-products of the activity of enhancers, which associate with promoters as part of their role as long-range gene regulatory sites. Overall, however, we find that most of the genome is not appreciably transcribed. 

Citation: van Bakel H, Nislow C, Blencowe BJ, Hughes TR (2010) Most “Dark Matter” Transcripts Are Associated With Known Genes. PLoS Biol 8(5): e1000371. doi:10.1371/journal.pbio.1000371 

Academic Editor: Sean R. Eddy, HHMI Janelia Farm, United States of America 

Received: December 3, 2009; Accepted: April 9, 2010; Published: May 18, 2010 

Copyright: © 2010 van Bakel et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. 

Funding: This work was supported by Genome Canada (http://www.genomecanada.ca) through the Ontario Genomics Institute, the Ontario Research Fund, and March of Dimes (http://www.marchofdimes.com). HvB was supported by the Netherlands Organization for Scientific Research (NWO; http://www.nwo.nl) (grant no. 825.06.033) and the Canadian Institutes of Health Research (CIHR; http://www.cihr-irsc.gc.ca/) (grant no. 193588). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. 

Competing interests: The authors have declared that no competing interests exist. 

Abbreviations: APA, alternative cleavage and polyadenylation; BW, bandwidth parameter; CAGE, capped analysis of gene expression; CNV, copy number variation; lincRNAs, large intervening noncoding RNAs; ncRNAs, noncoding RNAs; ORF, open reading frames; pasRNA, promoter-associated RNA; TSS, transcription start site; TTS, transcription termination site; TU, transcript unit; TUF, transcript of unknown function 

* E-mail: t.hughes@utoronto.ca

+++++


+++++

PERGUNTA INDISCRETA DO BLOGGER:

Quer dizer então que a turma do ENCODE pisou na bola na transcrição de genomas??? Pereça tal pensamento.  

+++++

Vote neste blog para o prêmio TOPBLOG 2010.

Redes de genomas enraízam a Árvore da Vida entre os domínios procarióticos

Genome Biology and Evolution Vol. 2:379; doi:10.1093/gbe/evq025 

Genome Networks Root the Tree of Life between Prokaryotic Domains 

Tal Dagan*,,1, Mayo Roettger,1, David Bryant2 and William Martin1 

1 Institute of Botany III, Heinrich-Heine University of Düsseldorf, Düsseldorf, Germany
2 Department of Mathematics, University of Auckland, Auckland, New Zealand 

* Corresponding author: E-mail: tal.dagan@uni-duesseldorf.de. 

Abstract 

Eukaryotes arose from prokaryotes, hence the root in the tree of life resides among the prokaryotic domains. The positionof the root is still debated, although pinpointing it would aid our understanding of the early evolution of life. Because prokaryote evolution was long viewed as a tree-like process of lineage bifurcations, efforts to identify the most ancient microbial lineage split have traditionally focused on positioning a root on a phylogenetic tree constructed from one or several genes. Such studies have delivered widely conflicting results on the position of the root, this being mainly due to methodological problems inherent to deep gene phylogeny and the workings of lateral gene transfer among prokaryotes over evolutionary time. Here, we report the position of the root determined with whole genome data using network-based procedures that take into account both gene presence or absence and the level of sequence similarity among all individual gene families that are shared across genomes. On the basis of 562,321 protein-coding gene families distributed across 191 genomes, we find that the deepest divide in the prokaryotic world is interdomain, that is, separating the archaebacteria from the eubacteria. This result resonates with some older views but conflicts with the results of most studies over the last decade that have addressed the issue. In particular, several studies have suggested that the molecular distinctness of archaebacteria is not evidence for their antiquity relative to eubacteria but instead stems from some kind of inherently elevated rate of archaebacterial sequence change. Here, we specifically test for such a rate elevation across all prokaryotic lineages through the analysis of all possible quartets among eight genes duplicated in all prokaryotes, hence the last common ancestor thereof. The results show that neither the archaebacteria as a group nor the eubacteria as a group harbor evidence for elevated evolutionary rates in the sampled genes, either in the recent evolutionary past or in their common ancestor. The interdomain prokaryotic position of the root is thus not attributable to lineage-specific rate variation. 

Keywords: phylogenies, early evolution, tree of life, microbial genomics, lateral gene transfer 

Accepted May 12, 2010 

These authors contributed equally to this work. 

Associate editor: Eugene Koonin 

+++++


+++++

Vote neste blog para o prêmio TOPBLOG 2010.

A floresta filogenética e a busca pela ilusória Árvore da Vida de Darwin


The Phylogenetic Forest and the Quest for the Elusive Tree of Life


1. E.V. Koonin, 
2. Y.I. Wolf and 
3. P. Puigbò
-
Author Affiliations

1. National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, Maryland 20894
1. Correspondence: koonin@ncbi.nlm.nih.gov

Abstract

Extensive horizontal gene transfer (HGT) among prokaryotes seems to undermine the tree of life (TOL) concept. However, the possibility remains that the TOL can be salvaged as a statistical central trend in the phylogenetic “forest of life” (FOL). A comprehensive comparative analysis of 6901 phylogenetic trees for prokaryotic genes revealed a signal of vertical inheritance that was particularly strong among the 102 nearly universal trees (NUTs), despite the high topological inconsistency among the trees in the FOL, most likely, caused by HGT. The topologies of the NUTs are similar to the topologies of numerous other trees in the FOL; although the NUTs cannot represent the FOL completely, they reflect a significant central trend. Thus, the original TOL concept becomes obsolete but the idea of a “weak” TOL as the dominant trend in the FOL merits further investigation. The totality of gene trees comprising the FOL appears to be a natural representation of the history of life given the inherent tree-like character of the replication process.

Copyright © 2009, Cold Spring Harbor Laboratory Press


+++++

NOTA CAUSTICANTE DO BLOGGER:

Árvore da Vida ilusória??? O conceito de Árvore da Vida de Darwin se torna obsoleta??? Caracas, mano, acho que uma hora dessas os agentes da KGB (revisores) da Nomenklatura científica devem estar fazendo enorme pressão sobre Koonin que ousou ir de encontro com uma das maiores ideias que toda a humanidade já teve: o ancestral comum...

Num sei não, mas acho que tem muito nego e nega que uma horas dessas deve estar bufando de raiva deste blogger. Eu num tô nem aí pra ocês, sô!!! Para mim, contrariando Dobzhansky, um Darwinista de Cristo, o que vale são as evidências, que se dane a teoria!!!

É por essa e outras que, há pouco mais de uma década, eu sou pós-darwinista.


P.S.: Traduzi elusive por ilusório, mas pode ser traduzido também como muito difícil de compreensão. Para mim, muito difícil de compreensão é milagre, e milagre não faz parte da ciência. Ou será que há rumores de anjos na epistemologia???

+++++

Vote neste blog para o prêmio TOPBLOG 2010.

    A transferência horizontal de genes na evolução: fatos e desafios

    Horizontal gene transfer in evolution: facts and challenges 

    1. Luis Boto* 

    -Author Affiliations 1. Departamento Biodiversidad y Biología Evolutiva , Museo Nacional Ciencias Naturales, CSIC, C/José Gutierrez Abascal 2, 28006 Madrid , Spain 

    1. *mcnb119@mncn.csic.es 

    Abstract 

    The contribution of horizontal gene transfer to evolution has been controversial since it was suggested to be a force driving evolution in the microbial world. In this paper, I review the current standpoint on horizontal gene transfer in evolutionary thinking and discuss how important horizontal gene transfer is in evolution in the broad sense, and particularly in prokaryotic evolution. I review recent literature, asking, first, which processes are involved in the evolutionary success of transferred genes and, secondly, about the extent of horizontal gene transfer towards different evolutionary times. Moreover, I discuss the feasibility of reconstructing ancient phylogenetic relationships in the face of horizontal gene transfer. Finally, I discuss how horizontal gene transfer fits in the current neo-Darwinian evolutionary paradigm and conclude there is a need for a new evolutionary paradigm that includes horizontal gene transfer as well as other mechanisms in the explanation of evolution. 

    · evolution · horizontal gene transfer · evolutionary mechanisms 

    Footnotes 

    o Received September 15, 2009. 

    o Accepted October 9, 2009. 

    · © 2009 The Royal Society

    +++++


    +++++

    NOTA TRIUNFANTE DESTE BLOGGER:

    O autor destaca que há necessidade de uma mudança paradigmática em evolução. E quem levantou esta lebre em 1998 junto à editoria de ciência da Folha de São Paulo foi este simples professorzinho do ensino médio (um dos meninos e meninas da Galera de Darwin me nomeou assim. Tenho orgulho de ser educador), mas a Grande Mídia vive uma relação incestuosa com a Nomenklatura científica, e quando a questão é Darwin, é tutti cosa nostra, capice? O que Darwin tem de melhor, a gente mostra; o que Darwin tem de ruim, a gente esconde. É a síndrome ricuperiana.

    Fui, nem sei por que, pensando: nada se pode contra a verdade, e a verdade científica sobre o status epistêmico da teoria da evolução através da seleção natural é que a teoria do século 19, recauchutada no século 20, não fecha as contas no contexto de justificação teórica do século 21.

    Senhores, a ciência abomina o vácuo teórico. Colocar uma década para elaborar uma nova teoria de evolução -- a SÍNTESE EVOLUTIVA AMPLIADA, é empurrar com a barriga que a biologia evolutiva vive uma crise paradigmática muito séria, e que Darwin já não serve mais como Norte na questão da origem das espécies, y otras cositas mais.

    E o MEC/SEMTEC/PNLEM tem a cara de pau de engabelar os estudantes do ensino médio com uma teoria científica anunciada como morta em 1980 por ninguém nada menos do que Stephen Jay Gould. 

    O nome disso é 171 epistêmico.

    +++++

    Vote neste blog para o prêmio TOPBLOG.

    De volta às aulas de biologia: a evolução darwiniana à luz da genômica


    Nucleic Acids Research Advance Access published online on February 12, 2009 

    Nucleic Acids Research, doi:10.1093/nar/gkp089

    Darwinian evolution in the light of genomics

    Eugene V. Koonin*

    National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, MD, USA

    *To whom correspondence should be addressed. Tel: 301 496 2477 (Ext 294); Fax: 30 480 9241; Email: koonin@ncbi.nlm.nih.gov

    Received January 9, 2009. Revised January 30, 2009. Accepted February 4, 2009.

    Comparative genomics and systems biology offer unprecedented opportunities for testing central tenets of evolutionary biology formulated by Darwin in theOrigin of Species in 1859 and expanded in the Modern Synthesis 100 years later. Evolutionary-genomic studies show that natural selection is only one of the forces that shape genome evolution and is not quantitatively dominant, whereas non-adaptive processes are much more prominent than previously suspected. Major contributions of horizontal gene transfer and diverse selfish genetic elements to genome evolution undermine the Tree of Life concept. An adequate depiction of evolution requires the more complex concept of a network or ‘forest’ of life. There is no consistent tendency of evolution towards increased genomic complexity, and when complexity increases, this appears to be a non-adaptive consequence of evolution under weak purifying selection rather than an adaptation. Several universals of genome evolution were discovered including the invariant distributions of evolutionary rates among orthologous genes from diverse genomes and of paralogous gene family sizes, and the negative correlation between gene expression level and sequence evolution rate. Simple, non-adaptive models of evolution explain some of these universals, suggesting that a new synthesis of evolutionary biology might become feasible in a not so remote future.

    +++++


    +++++

    NOTA TRIUNFANTE DESTE BLOGGER:

    Desde o início este blog anunciou a iminência e eminência de uma mudança paradigmática em biologia evolutiva. A Nomenklatura científica nem txum pra mim. A Galera dos meninos e meninas de Darwin desceram o cacete neste baixinho em todos os blogs e forúns na internet.

    Em ciência, nada como um dia atrás do outro, pois a ciência é a busca pela verdade. Por que ar de triunfalismo deste blogger? Porque ninguém ousou tocar nesta questão por demais complexa, controversa e polêmica: a origem e evolução das espécies. A Nomenklatura científica enfiou o rabo epistêmico entre as pernas, e ficou muda. A Galera dos meninos e meninas de Darwin continuaram os ataques ad hominem, e nada apresentaram de substancial. Aqui, não. Aqui, a gente mata a cobra de Down e mostra o pau.

    A verdade científica hoje pode se revelar uma mentira amanhã. A tal de Árvore da Vida de Darwin é uma dessas verdades que se mostrou hoje como uma mentira, oops, uma ilusão, miragem epistêmica. E o que tudo isso significa? O que este blogger e outros críticos e oponentes de Darwin sempre falaram: uma revisão ou simplesmente descarte do Darwinismo como explicação científica. Traduzindo em graúdos: que venga logo la nueva teoría de evolución -- a SÍNTESE EVOLUTIVA AMPLIADA, que pela montanha de evidências contrárias como as destacadas por Koonin, não pode e nem deve ser selecionista!

    Alô MEC/SEMTEC/PNLEM: nada de aprovar livros didáticos de Biologia do ensino médio com este conceito de Árvore da Vida que não é corroborado pelas evidências encontradas na natureza. Eu estou de olho! Saboteur, chérie, epistemologique saboteur!!!

    Fui, nem sei por que, rindo que nem o gato de Cheshire de Alice no País das Maravilhas de Lewis Carrol...

    Vote neste blog para o prêmio TOPBLOG 2010.

    Morfossauros, os mestres do disfarce enganaram os especialistas por décadas

    quinta-feira, julho 29, 2010


    Morph-osaurs: How shape-shifting dinosaurs deceived us 


    28 July 2010 by Graham Lawton 

    Magazine issue 2771. 

    DINOSAURS were shape-shifters. Their skulls underwent extreme changes throughout their lives, growing larger, sprouting horns then reabsorbing them, and changing shape so radically that different stages look to us like different species. 

    This discovery comes from a study of the iconic dinosaur triceratops and its close relative torosaurus. Their skulls are markedly different but are actually from the very same species, argue John Scannella and Jack Horner at the Museum of the Rockies in Bozeman, Montana. 

    Triceratops had three facial horns and a short, thick neck-frill with a saw-toothed edge. Torosaurus also had three horns, though at different angles, and a much longer, thinner, smooth-edged frill with two large holes in it. So it's not surprising that Othniel Marsh, who discovered both in the late 1800s, considered them to be separate species. 



    Now Scannella and Horner say that triceratops is merely the juvenile form of torosaurus. As the animal aged, its horns changed shape and orientation and its frill became longer, thinner and less jagged. Finally it became fenestrated, producing the classic torosaurus form (see diagram, right). 

    This extreme shape-shifting was possible because the bone tissue in the frill and horns stayed immature, spongy and riddled with blood vessels, never fully hardening into solid bone as happens in most animals during early adulthood. The only modern animal known to do anything similar is the cassowary, descended from the dinosaurs, which develops a large spongy crest when its skull is about 80 per cent fully grown. 

    Shape-shifting continued throughout these dinosaurs' lives, Scannella says. "Even in the most mature specimens that we've examined, there is evidence that the skull was still undergoing dramatic changes at the time of death." 

    Scannella and Horner examined 29 triceratops skulls and nine torosaurus skulls, mostly from the late-Cretaceous Hell Creek formation in Montana. The triceratops skulls were between 0.5 and 2 metres long. By counting growth lines in the bones, not unlike tree rings, they have shown clearly that the skulls come from animals of different ages, from juveniles to young adults. Torosaurus fossils are much rarer, 2 to 3 metres long and, crucially, only adult specimens have ever been found. 

    The duo say there is a clear transition from triceratops into torosaurus as the animals grow older. For example, the oldest specimens of triceratops show a marked thinning of the bone where torosaurus has holes, suggesting they are in the process of becoming fenestrated (Journal of Vertebrate Paleontology, vol 30, p 1157). 

    The finding has implications for the supposed defensive function of the triceratops' frill. "If I was a triceratops I wouldn't want anything too damaging to happen to my frill, as it had numerous large blood vessels running over the surface," says Scannella. "I don't imagine holding up a thin bony shield that can gush blood would be a very effective means of defence." 

    Instead it is likely that the headgear was a display to signal an individual's maturity to other members of the species. Differences between the sexes is another possibility but less likely, says Scannella. 

    It was already known that triceratops skulls changed throughout their development, but not that the final result was a torosaurus. Torosaurus will now be abolished as a species and specimens reassigned to Triceratops, says Horner. 

    Triceratops isn't the only shape-shifter. Last year, Horner and Mark Goodwin of the University of California, Berkeley, claimed something similar for another iconic Hell Creek dinosaur, the dome-headed pachycephalosaurus, perhaps best known for headbutting jeeps in Jurassic Park 2. 

    Two similar dinosaurs, classified as Dracorex and Stygimoloch, are also known from Hell Creek. Horner and Goodwin say that they are not separate species but juveniles of pachycephalosaurus (PLoS One, vol 4, p e7676 FREE PDF). If so, this is an even more extreme case of shape-shifting than triceratops, with the animal growing horns and then re-absorbing them into its skull as it ages(see diagram).
    +++++

    Read more here/Leia mais aqui: New Scientist

    +++++
    Vote neste blog para o prêmio TOPBLOG 2010.