Last #FossilFriday our Deputy Keeper of Natural History Paolo took a look at some of the fabulous fossil specimens soon to be installed in our Natural History Gallery and some of the fantastic stories used to explain them. Our upcoming Gallery redisplay will also cover the foundations of scientific principles we now use to understand these collections.
The 1700s was a time of considerable change in society, with the Enlightenment principles of reason and investigation supporting a scientific revolution. In this exciting time of social upheaval, the foundations of geology were being laid down, based on principles of slow and steady change.
Chemist, agriculturist and physician James Hutton observed the geology of the Scottish landscape and formulated the principle of uniformitarianism. This is the idea that rather than being the result of a catastrophic biblical flood, rock features were formed by the same processes of erosion and deposition that we see happening today, but taking place over an incredibly long period of time.
This heralded the beginning of a period where fossils were understood through scientific principles rather than the fabulous and fantastic theories of folklore we explored in a previous blog post.
Uniformitarianism combined with the theory of superposition (where younger rock layers or ‘strata’ are laid down on top of older strata) allowed relative ages of rock beds in a sequence to be worked out (this is called stratigraphy). The types of fossil found in certain strata proved useful for working out the relative ages of rocks in different places. The sediments in a bed may vary, but two beds with the same fossils would be closer in age than those with very different fossils.
Once the relationships between fossils, strata and age were better understood, it became possible to map what was happening underground. This was important for miners and the engineers digging canals and railway tunnels to cope with the transport needs of the Industrial Revolution of the 1700s.
The first geological map was produced in Britain by engineer William Smith almost 200 years ago, although it has been improved on since then, his first attempt was remarkably accurate.
The idea of uniformitarianism also changed how fossils were considered in terms of the organisms they represented. When William Buckland discovered a cave containing Hyaena bones in Yorkshire in 1822, he was able to work out that it was used as a den when the animals were alive. This discovery captured the scientific imagination and helped set the standard for palaeontological research.
New scientific thinking about the age of the Earth challenged traditional ideas that the Earth had been around for just a few thousand years, and introduced the idea that Earth may be millions of years old (we have since discovered that is in fact 4.6 billion years old). This older age for the Earth offered a much longer time for changes to occur, both to the planet and to the organisms living on it – providing scope for evolution to occur.
The Natural History Gallery's new displays will be opening to the public in March 2015. Keep an eye out next year for more blogs from Paolo all about the scientific stories told in our galleries.