What would you like to do on your 30th birthday? Shut down for two years and replace your major organs? It may not sound like an ideal celebration, but that is what the European Synchrotron Radiation Facility (ESRF) will do this December.
The world’s first third-generation synchrotron light source (ESRF) was built in 1988, and will pause the world’s “most intense X-rays for research” to enable the construction of a new storage ring and the addition of even more beam lines. The Extremely Brilliant Source (EBS) is not scheduled to come back online until late 2020.
I feel especially lucky to have been here in beautiful Grenoble this week working with colleagues from Uppsala University, Sophie Sanchez and Per Ahlberg, on the very final experiment on beamline ID 19 before the scheduled shutdown. ESRF is the only synchrotron in the world with a beam powerful enough to perform this experiment at the super high resolution required (down to 0.7μm voxel size!).
Per and Sophie inspecting a mounted specimen on the ID19 beamline at ESRF
During 72 hours of beam time, we work 24/7 with help from ESRF researcher, Paul Tafforeau, to scan as many specimens as possible. Sophie’s project is looking at the bone histology of the fins and limbs over a number of significant evolutionary transitions: the fin-limb, water-land, and the characteristics that appear in the first amniotes (animals that lay a waterproof egg, e.g. the first reptiles).
Bone histology can be remarkably informative about the lifestyle and life history traits of an animal. For example, the bone microstructure can indicate whether an animal matured quickly, or had a long juvenile phase – as shown recently by Sophie and colleagues in Sanchez et al. (2016) and other works.
Alice setting up a specimen(left), and Laugia, a Triassic coelacanth from Greenland (right), scanned at the ESRF
Skeletochronology works on the same concept as counting tree rings in trees, and can map various changes in life history, development and physiology inside the bones of an animal. And very significantly for these experiments, the structure of the bone can indicate whether the bone was capable of sustaining an animal’s weight on land, or if it must have remained buoyant in the water.
It’s been an exhausting yet exciting few days scanning many stunning specimens sourced from all over the world. I look forward to continuing our work on these projects in the coming years (and catching up on some sleep!)
Alice and Sophie at the ESRF in December 2018