Unlocking the Secrets of Darwin’s Preserved Specimens with Laser Technology
For two centuries, rows of preserved specimen jars from Charles Darwin’s legendary Galapagos voyage have remained sealed in the archives of London’s Natural History Museum (NHM). Thanks to cutting-edge laser technology, scientists have now been able to peer inside these jars without ever cracking them open.
Charles Darwin, renowned for his groundbreaking theory of natural selection and evolution, drew inspiration from the diverse wildlife he encountered during his time aboard the HMS Beagle in the Galapagos Islands. The preserved specimens from his voyage, which include mammals, reptiles, fish, and shrimps, have provided valuable insights into the natural world.
Until recently, the exact composition of the preservation fluids in these jars has remained a mystery. Opening the jars posed significant risks such as evaporation, contamination, and environmental damage to the specimens within. However, a team of scientists led by NHM research technician Wren Montgomery and physicist Sara Mosca from the UK’s Science and Technology Facilities Council have found a non-invasive solution.
Through the use of spatially offset Raman spectroscopy (SORS), a portable form of laser spectroscopy, the researchers were able to analyze the contents of the jars without compromising their integrity. This innovative technique measures the molecular structure of materials by analyzing the reemitted light following laser excitation, providing a detailed chemical fingerprint of the preservation fluids.
The study, published in ACS Omega, revealed that the preservation fluids in Darwin’s jars were predominantly formalin and ethanol for mammals and reptiles, while invertebrates like jellyfish and shrimp were stored in formaldehyde or buffered formaldehyde with additional compounds for tissue preservation.
Understanding the composition of these preservation fluids is crucial for the long-term care and conservation of these invaluable specimens. With over 100 million fluid-preserved specimens housed in museums worldwide, this non-invasive technique offers a new way to monitor and safeguard these scientific treasures for future generations.
By unlocking the secrets hidden within Darwin’s preserved specimens, scientists are not only honoring his legacy but also paving the way for new discoveries and advancements in the field of natural history research.
