Uniformitarianism - A theory, propounded by James Hutton and championed by Charles Lyell, that held that the earth had been shaped by uniform geological forces – erosion by running water, accumulation of sediment, earthquakes, and volcanoes. These forces, operating through millennia and still at work, made the earth what it is today, went the theory, and there was no need for catastrophe to explain landforms. Lyell also applied this theory to biology, holding that survival of a given species against new ones emerging depended on conditions of environment, which were changed by geological processes. Lyell could not explain how new species originated. Darwin carried a copy of Lyell's Principles of Geology with him on the Beagle.
More about Lyell, with a caricature of him as an Ichthyosaur

The Difference Dictionary was first published
in slightly different form in Science Fiction Eye, Issue #8.
Text copyright 1990, 1996, 2000, 2003,
by Eileen K. Gunn.