The theory that maintains that although some changes in the earth's surface are immediately observable and caused by erosion and other natural processes, other changes are caused by gradual processes over extremely long periods of time is called:​

A) ​natural selection
B) ​catastrophism
C) ​linearism
D) ​uniformitarianism

Uniformitarianism

The geological principle suggesting that the same processes and natural laws that operate in the universe now have always operated in the past.

Natural Selection

A fundamental mechanism of evolution, where organisms better adapted to their environment tend to survive and produce more offspring.

Catastrophism

The theory that the Earth has been shaped by sudden, short-lived, violent events, possibly worldwide in scope, contrasting with uniformitarianism which emphasizes gradual changes.