Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Scientists reassemble the backbone of life with a particle acceleratorynchrotron X-rays

14.01.2013
Earliest evolutionary attempt to produce a bony sternum identified

Jointly issued with STFC and the Royal Veterinary College London.


This is an artist's impression of an Ichthyostega Tetrapod, with the cut-out showing the 3-D reconstruction of two vetrebrae from the study.

Credit: Julia Molnar

Scientists have been able to reconstruct, for the first time, the intricate three-dimensional structure of the backbone of early tetrapods, the earliest four-legged animals. High-energy X-rays and a new data extraction protocol allowed the researchers to reconstruct the backbones of the 360 million year old fossils in exceptional detail and shed new light on how the first vertebrates moved from water onto land. The results are published 13 January 2013 in Nature.

The international team of scientists was led by Stephanie E. Pierce from The Royal Veterinary College in London and Jennifer A. Clack from the University of Cambridge. It also comprised scientists from Uppsala University (Sweden) and the European Synchrotron Radiation Facility ESRF in Grenoble (France).

The tetrapods are four-limbed vertebrates, which are today represented by amphibians, reptiles, birds and mammals. Around 400 million years ago, early tetrapods were the first vertebrates to make short excursions into shallower waters where they used their four limbs for moving around. How this happened and how they then transferred to land is a subject of intense debate among palaeontologists and evolution biologists.

All tetrapods have a backbone, or vertebral column, which is a bony structure common to all other vertebrates including fish, from which tetrapods evolved. A backbone is formed from vertebrae connected in a row - from head to tail. Unlike the backbone of living tetrapods (e.g. humans), in which each vertebra is composed of only one bone, early tetrapods had vertebrae made up of multiple parts.

"For more than 100 years, early tetrapods were thought to have vertebrae composed of three sets of bones - one bone in front, one on top, and a pair behind. But, by peering inside the fossils using synchrotron X-rays we have discovered that this traditional view literally got it back-to-front," says Stephanie Pierce who is the lead author of the publication.

For the analysis, the European Synchrotron Radiation Facility (ESRF) in France, where the three fossil fragments were scanned with X-rays, applied a data extraction method to reveal tiny details of fossil bones buried deep inside the rock matrix. The fossilised bones are embedded in rock so dense it absorbs most of the X-rays. "Without the new method, it would not have been possible to reveal the elements of the spine in three dimensions with a resolution of 30 micrometres" says Sophie Sanchez from University of Uppsala and ESRF who is a co-author of the publication.

In these high-resolution X-ray images, the scientists discovered that what was thought to be the first bone - known as the intercentrum - is actually the last in the series. And, although this might seem like a trivial oversight, this re-arrangement in vertebral structure has over-arching ramifications for the functional evolution of the tetrapod backbone.

Stephanie Pierce explains: "By understanding how each of the bones fit together we can begin to explore the mobility of the spine and test how it may have transferred forces between the limbs during the early stages of land movement".

But, the findings didn't end there. One of the animals - known as Ichthyostega - was also found to have an assortment of hitherto unknown skeletal features including a string of bones extending down the middle of its chest.

Jennifer Clack says: "These chest bones turned out to be the earliest evolutionary attempt to produce a bony sternum. Such a structure would have strengthened the ribcage of Ichthyostega, permitting it to support its body weight on its chest while moving about on land."

This unexpected discovery supports recent work by Pierce and Clack that showed Ichthyostega probably moved by dragging itself across flat ground using synchronous 'crutching' motions of its front legs - much like that of a mudskipper or seal. Dr Pierce adds: "The results of this study force us to re-write the textbook on backbone evolution in the earliest limbed animals."

"At the ESRF, the new data extraction protocol makes it possible to study fossils in dense and heavy rock in unprecedented detail. What we have seen today is only the beginning of more surprises to come," concludes Sophie Sanchez.

Reference:

Stephanie E Pierce, Per E Ahlberg, John R Hutchinson, Julia L Molna, Sophie Sanchez, Paul Tafforeau, and Jennifer A Clack: Vertebral architecture in the earliest stem tetrapods, Nature advanced online publication 13 January 2013, DOI: 10.1038/nature11825.

Claus Habfast | EurekAlert!
Further information:
http://www.esrf.fr

More articles from Earth Sciences:

nachricht Monitoring lava lake levels in Congo volcano
16.05.2018 | Seismological Society of America

nachricht Ice stream draining Greenland Ice Sheet sensitive to changes over past 45,000 years
14.05.2018 | Oregon State University

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Explanation for puzzling quantum oscillations has been found

So-called quantum many-body scars allow quantum systems to stay out of equilibrium much longer, explaining experiment | Study published in Nature Physics

Recently, researchers from Harvard and MIT succeeded in trapping a record 53 atoms and individually controlling their quantum state, realizing what is called a...

Im Focus: Dozens of binaries from Milky Way's globular clusters could be detectable by LISA

Next-generation gravitational wave detector in space will complement LIGO on Earth

The historic first detection of gravitational waves from colliding black holes far outside our galaxy opened a new window to understanding the universe. A...

Im Focus: Entangled atoms shine in unison

A team led by Austrian experimental physicist Rainer Blatt has succeeded in characterizing the quantum entanglement of two spatially separated atoms by observing their light emission. This fundamental demonstration could lead to the development of highly sensitive optical gradiometers for the precise measurement of the gravitational field or the earth's magnetic field.

The age of quantum technology has long been heralded. Decades of research into the quantum world have led to the development of methods that make it possible...

Im Focus: Computer-Designed Customized Regenerative Heart Valves

Cardiovascular tissue engineering aims to treat heart disease with prostheses that grow and regenerate. Now, researchers from the University of Zurich, the Technical University Eindhoven and the Charité Berlin have successfully implanted regenerative heart valves, designed with the aid of computer simulations, into sheep for the first time.

Producing living tissue or organs based on human cells is one of the main research fields in regenerative medicine. Tissue engineering, which involves growing...

Im Focus: Light-induced superconductivity under high pressure

A team of scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg investigated optically-induced superconductivity in the alkali-doped fulleride K3C60under high external pressures. This study allowed, on one hand, to uniquely assess the nature of the transient state as a superconducting phase. In addition, it unveiled the possibility to induce superconductivity in K3C60 at temperatures far above the -170 degrees Celsius hypothesized previously, and rather all the way to room temperature. The paper by Cantaluppi et al has been published in Nature Physics.

Unlike ordinary metals, superconductors have the unique capability of transporting electrical currents without any loss. Nowadays, their technological...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Save the date: Forum European Neuroscience – 07-11 July 2018 in Berlin, Germany

02.05.2018 | Event News

Invitation to the upcoming "Current Topics in Bioinformatics: Big Data in Genomics and Medicine"

13.04.2018 | Event News

Unique scope of UV LED technologies and applications presented in Berlin: ICULTA-2018

12.04.2018 | Event News

 
Latest News

Supersonic waves may help electronics beat the heat

18.05.2018 | Power and Electrical Engineering

Keeping a Close Eye on Ice Loss

18.05.2018 | Information Technology

CrowdWater: An App for Flood Research

18.05.2018 | Information Technology

VideoLinks
Science & Research
Overview of more VideoLinks >>>