Uniformitarianism

"The Present Is the Key to the Past"

Asia , day and night, satellite image of the Earth
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Uniformitarianism is a geological theory that describes the processes shaping the earth and the Universe. It states that changes in the earth's crust throughout history have resulted from the action of uniform, continuous processes that are still occurring today.

Overview

In the mid-seventeenth century, biblical scholar and Archbishop James Ussher determined that the earth had been created in the year 4004 B.C. Just over a century later, James Hutton, known as the father of geology, suggested that the earth was much older and that processes occurring in the present were the same as those that had operated in the past and that will operate in the future.

This concept became known as uniformitarianism and can be summarized by the phrase "the present is the key to the past." It was a direct rejection of the prevalent theory of the time, catastrophism, which held that only violent disasters could modify the surface of the earth.

Today, we hold uniformitarianism to be true and know that great disasters such as earthquakes, asteroids, volcanoes, and floods are also part of the regular cycle of the earth.

The Earth is estimated to be approximately 4.55 billion years old and the planet has certainly had enough time for abrupt, as well as slow, continuous processes to mold and shape the earth—including the tectonic movement of the continents around the globe.

The Evolution of Uniformitarianism Theory

The two major scientists in the advancement from catastrophism towards uniformitarianism were the 18th-century Scottish framer and geologist James Hutton and the 19th-century British lawyer-turned-geologist Charles Lyell.

James Hutton

Hutton based his theory on the slow, natural processes that he observed on the landscape. He realized that, if given enough time, a stream could carve a valley, ice could erode rock, sediment could accumulate and form new landforms. He speculated that millions of years would have been required to shape the earth into its contemporary form.

Unfortunately, Hutton isn't often associated with uniformitarianism. Even though he published his "Theory of the Earth" and presented its abstract to the Royal Society of Edinburgh, a lot of criticism followed and the times weren't ready for his ideas. Hutton did publish a three-volume book on the topic, but his writing was so complicated that it failed to win him deserved recognition.

However, the famous line that became associated with uniformitarianism—"we find no vestige of a beginning, no prospect of an end"—does come from Hutton's 1785 paper on the entirely new theory of geomorphology (the study of landforms and their development).

Sir Charles Lyell

It was the 19th-century scholar Sir Charles Lyell whose "Principles of Geology" popularized the concept of uniformitarianism. In Lyell's time, catastrophism was still very popular, which pushed him to question the standard of the times and turn to Hutton's theories. He traveled Europe, searching for evidence to prove Hutton's ideas and eventually, his work became one of the most influential of the century.

The name "uniformitarianism" itself comes from William Whewell, who coined the term in his review of Lyell's work.

To Lyell, the history of both earth and life was vast and directionless and his work became so influential that Darwin's own theory of evolution follows the same principle of slow, almost imperceptible changes. University of California Museum of Paleontology states that "Darwin envisioned evolution as a sort of biological uniformitarianism."

Severe Weather and Uniformitarianism

As the concepts of uniformitarianism evolved, it has adapted to include an understanding of the importance of short-term "cataclysmic" events in the formation and shaping of the world. In 1994, the U.S. National Research Council stated:

It is not known whether the relocation of materials on the surface of the Earth is dominated by the slower but continuous fluxes operating all the time or by the spectacular large fluxes that operate during short-lived cataclysmic events.

On a practical level, uniformitarianism hinges upon the belief that both long-term patterns and short-term natural disasters reoccur throughout the course of history, and for that reason, we can look to the present to see what has happened in the past.

The rain from a storm slowly erodes the soil, wind moves sand in the Sahara desert, floods change the course of a river, volcano eruptions and earthquakes suddenly displace land masses, and in what occurs today uniformitarianism unlocks the keys to the past and the future.

Yet modern geologists also realize that not all processes that were at work in the past are happening today. The first millions of years of Earth's history were vastly different from our current conditions. There were times when Earth was showered with solar debris or when plate tectonics didn't exist as we know them.

In this way, instead of being conceived of as an absolute truth, uniformitarianism provides us with another explanation that helps create a more complete picture of the processes that shape the Earth and the Universe.

Sources

  • Robert Bates and Julia Jackson, Glossary of Geology, 2nd edition, American Geological Institute, 1980, pg. 677
  • Davis,​​​ Mike. ECOLOGY OF FEAR: Los Angeles and the Imagination of Disaster. Macmillan, 1998.​
  • Lyell, Charles. Principles of Geology. Hilliard, Gray & Co., 1842.
  • Tinkler, Keith J. A Short History of Geomorphology. Barnes & Noble Books, 1985
  • "Uniformitarianism: Charles Lyell" Understanding Evolution. 2019. University of California Museum of Paleontology.