Evolutionary Biology/James Hutton
Hutton (1726–1797) is best known for his theory of gradualism. Hutton was a geologist who left the medical field in order to travel and study the earth's surface. When Hutton's ideas began to circulate, geology was not a subject that was given much attention. The focus of the time was mineralogy.
In 1785, Hutton published his paper titled ‘Theory of the Earth.’ In this paper, he explained how the study of geology confines itself as the study of the material makeup of the earth. He suggested many explanations and origins for many geological occurrences ranging from molten rock formations to the origins of materials found on sea floors.
Hutton began his paper with his studies of atmospheric changes in a section he termed ‘Theory of Rain.’ In this section of his paper, Hutton went into detail of how moisture accumulates in the atmosphere until enough has gathered to form a dense moisture filled cloud with visible precipitate in the form of rain.
It was not until the third version of the Theory of the Earth was published when Hutton introduced his theory of gradualism. This is where he recognized that change did occur, but that change was the gradual culmination of slow processes happening over great amounts of time. By using this idea, it is possible to observe the earth today and make assumptions about the past since change happened over such a long period of time, the earth today must be relevant to the earth of the past.
Campbell, Reece. Biology, Sixth edition. Benjamin Cummings. 2001.