Final answer:
The concept developed by Charles Lyell that geologic processes have been consistent over time is called uniformitarianism, which contradicts the idea of catastrophism and suggests a much older Earth.
Step-by-step explanation:
The idea developed by Charles Lyell, which states that the geologic processes that shaped Earth in the past continue to operate in the same way today, is known as uniformitarianism. Lyell's work, including his major publication 'Principles of Geology,' suggests that the forces shaping our planet, such as erosion by water and wind, have remained consistent throughout Earth's history. This principle was a significant contrast to the then-prevailing belief in catastrophism, which argued for the formation of Earth's features by quick, large-scale events. Lyell's principle of uniformitarianism proposed that the slow and steady processes we observe shaping our planet now are the same that have been at work for millions of years, implying a much older Earth than previously thought, thus providing a timeline suitable for the gradual changes required for the evolution of species.