Dan tetap saja ada orang Islam di mailing list ini yang begitu dungunya hingga
masih bilang evolusi itu tidak terjadi...
Web address:
http://www.sciencedaily.com/releases/2012/10/
121017131834.htm
Evolutionary Origins of Our Pretty Smile
ScienceDaily (Oct. 17, 2012) â" It takes both teeth and jaws to make a pretty
smile, but the evolutionary origins of these parts of our anatomy have only
just been discovered, thanks to a particle accelerator and a long dead fish.
All living jawed vertebrates (animals with backbones, such as humans) have
teeth, but it has long been thought that the first jawed vertebrates lacked
pearly gnashers, instead capturing prey with gruesome scissor-like jaw-bones.
However new research, led by the University of Bristol and published October 17
in Nature, shows that these earliest jawed vertebrates possessed teeth too
indicating that teeth evolved along with, or soon after, the evolution of jaws.
Palaeontologists from Bristol, the Natural History Museum and Curtin
University, Australia collaborated with physicists from Switzerland to study
the jaws of a primitive jawed fish called Compagopiscis.
The international team studied fossils of Compagopiscis using high energy
X-rays at the Swiss Light Source at the Paul Scherrer Institut in Switzerland,
revealing the structure and development of teeth and bones.
Lead author, Dr Martin Ruecklin of the University of Bristol said: "We were
able to visualise every tissue, cell and growth line within the bony jaws,
allowing us to study the development of the jaws and teeth. We could then make
comparisons with the embryology of living vertebrates, thus demonstrating that
placoderms possessed teeth."
Co-author, Professor Philip Donoghue of the University of Bristol's School of
Earth Sciences said: "This is solid evidence for the presence of teeth in these
first jawed vertebrates and solves the debate on the origin of teeth."
Co-author Dr Zerina Johanson from the Natural History Museum said: "These
wonderfully preserved fossils from Australia yield many secrets of our
evolutionary ancestry but research has been held back waiting for the kind of
non-destructive technology that we used in this study. Without the
collaborations between palaeontologists and physicists, our evolutionary
history would remain hidden in the rocks."
Professor Marco Stampanoni of the Paul Scherrer Institut said: "We performed
non-invasive 3D microscopy on the sample using synchrotron radiation, a very
powerful X-ray source. This technique allows us to obtain a perfect digital
model and very detailed insight views of the old fossil without destroying it.
Normally, our method delivers very high spatial resolution on tiny samples. For
this experiment we modified our setup and reconstruction algorithms in order to
expand the field of view significantly while keeping the spatial resolution
high."
This work was funded by the EU Framework Programme 7, the Natural Environment
Research Council and the Paul Scherrer Institut.
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Story Source:
The above story is reprinted from materials provided by University of
Bristol.
Note: Materials may be edited for content and length. For further
information, please contact the source cited above.
Journal Reference:
Martin Rücklin, Philip C. J. Donoghue, Zerina Johanson, Kate Trinajstic,
Federica Marone, Marco Stampanoni. Development of teeth and jaws in the
earliest jawed vertebrates. Nature, 2012; DOI: 10.1038/nature11555
Need to cite this story in your essay, paper, or report? Use one of the
following formats:
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MLA
University of Bristol (2012, October 17). Evolutionary origins of our pretty
smile. ScienceDaily. Retrieved October 17, 2012, from
http://www.sciencedaily.com /releases/2012/10/121017131834.htm
Note: If no author is given, the source is cited instead.
Disclaimer: This article is not intended to provide medical advice, diagnosis
or treatment. Views expressed here do not necessarily reflect those of
ScienceDaily or its staff.
Dan tetap saja ada orang Islam Minangkabau yang begitu dungunya hingga masih
bilang evolusi itu tidak terjadi...
http://www.sciencedaily.com/releases/2012/10/121017131834.htm
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