The monthly gathering of the Geoblogosphere - The Accretionary Wedge - hosted this time on the blog "In the Company of Plants and Rocks", is asking for my favourite geological illustration. There is a specific image that always intrigued me, even long before I came to appreciate the strange "geologic history" behind this sketch.
The 19th century Victorian Empire was characterized by a vivid interest in natural sciences and especially geology. It was a time of radical ideas and controversial new hypothesis, like the origin of rocks or fossils and the Ice Age theory. When direct criticism to a particular idea wasn't possible due gentleman's agreement, some researchers adopted an intriguing method to criticize a hypothesis or theoretical position of a fellow geologist.
The eminent British gentleman Sir Henry Thomas De la Beche (1796-1855) was one of the most prolific geologists of his time. His published works span from the description of fossil marine reptiles to the study of the British stratigraphy and various textbooks dealing with the application of geological survey methods. However he is best known by the public for his passion and talent for cartoons and caricatures. One of the most famous caricatures, still reproduced today in many geology textbooks, was drawn by De la Beche in 1830, the same year the geologist Sir Charles Lyell published his groundbreaking "Principles of Geology."
The prominent "Professor Ichthyosaurus", depicted in the cartoon entitled "Awful Changes", was considered for a long time to be inspired by the eccentric figure of geologist Reverend William Buckland (1784-1856) and his unusual teaching methods. The caricature was widely publicized in Francis Buckland's (1826-80) book-series "Curiosities of Natural History" (1857-72), in part a collection of strange natural phenomena and in part a biography of his fathers' life. The explanation that De la Beche provided the caricature for his good friend and the son's book seemed therefore reasonable.
Fig.1. "Awful Changes. Man Found only in a Fossil State - Reappearance of Ichthyosauri." - "A lecture, - 'You will at once perceive,' continued Professor Ichthyosaurus, 'that the skull before us belonged to some of the lower order of animals; the teeth are very insignificant, the power of the jaws trifling, and altogether it seems wonderful how the creature could have procured food." The caricature by De la Beches of "Prof. Ichthyosaurus" on the pages of Francis Trevelyan Buckland (Son of William Buckland) "Curiosities of Natural History" (image in public domain).
However the geologist and dedicated earth-science historian Martin J.S. Rudwick realized the connection of this scene with some drawings produced before 1831 by De la Beche in his diary, where he ridiculed the approach to geology as adopted by Sir Charles Lyell. In De la Beches diary a lawyer (the reference to Lyell, who actually was a lawyer, seems obvious) is carrying a bag with "his" theory around the world, or he is shown wearing particular glasses (like Professor Ichthyosaurus), and offering this "worldview" and the resulting "theoretical approach" to a geologist carrying a hammer, a reference to the applied field geologist like De la Beche.
De la Beche could not overcome his prejudice against Lyell as a lawyer, which he considered much more a geo-egghead then a real field-geologist.
So "Awful Changes" does in fact lampoon Lyell's uniformitarianism. Lyell rejected the prevalent idea of a young earth shaped by sudden unexplainable catastrophes. Not disasters and rapid changes formed the earth, but slow processes like deposition and erosion. These processes needed thousands, if not millions of years, to reshape the entire earth.
Lyell also adopts the idea of geological time as a cycle. He compares the history of the earth and the climatic changes that have occurred in the past with a "geologic year" - with fall, winter, spring and summer - as ordered and similar to the cyclical movements of earth around the sun.
Animal and plant species were perfectly adapted to these "geological seasons". When a "geological" season ended, some animal and plant species did diminish in abundance, meanwhile others flourished. This pattern was reversible at any time and according to Lyell's "Principles of Geology" so it was therefore possible that:
"Then might those genera of animals return, of which the memorials are preserved in the ancient rocks of our continents. The huge iguanodon might reappear in the woods, and the ichthyosaur in the sea, while the pterodactyl might flit again through the umbrageous groves of tree ferns."
It is this passage that inspired De la Beches famous caricature of "Professor Ichthyosaurus" complaining about the awful changes that geology experienced at the time…
CLARY, M.R. & WANDERSEE, J.H. (2010): Scientific Caricatures in the Earth Science Classroom: An Alternative Assessment for Meaningful Science Learning. Science & Education 19:21-37
GORDON, E.O. (1894): The Life and Correspondence of William Buckland. John Murray, London
HALLAM, A. (1998): Lyell's views on organic progression, evolution and extinction. In: BLUNDELL, D. J. & SCOTT, A. C. (eds) Lyell: the Past is the Key to the Present. Geological Society, London, Special Publications 143: 133-136.
LEEDER, M.R: (1998): Lyell's Principles of Geology: foundations of sedimentology. Geological Society, London, Special Publications 143: 95-110
RUDWlCK, M. S. (1975): Caricature as Source for the History of Science: DE LA BECHE'S Anti-Lyellian Sketches of 1831. Isis, Vol. 66 (234): 534-560
RUDWICK, M.J.S. (2008): Worlds before Adam - The Reconstruction of Geohistory in the Age of Reform. The University of Chicago Press: 614
SCOTT, M. (1996-2010): The Rocky Road to Modern Paleontology and Biology: Henry De la Beche. (Accessed 13.10.2010)
NAPIER, J. (1976): O rare Frank Buckland! New Scientist 16 December 1976: 647-649