Which term refers to the belief in the gradual evolution of species over time?

The belief in the gradual evolution of species over time is best encapsulated by the term "Evolutionary Theory." This concept is rooted in the understanding that species change through mechanisms such as natural selection, genetic drift, and mutation over long periods, leading to the diversity of life we see today. This theory is supported by extensive scientific evidence from various fields, including genetics, paleontology, and comparative anatomy, demonstrating how species adapt to their environments and how new species arise from common ancestors.

Other terms such as Creationism and Intelligent Design typically refer to belief systems that posit that life and the universe's complexity is a result of a deliberate creator, rather than a process of gradual evolution. Fundamentalism often refers to a strict adherence to specific religious beliefs and teachings, which can also conflict with the concepts of gradual evolutionary processes. In contrast, Evolutionary Theory is grounded in scientific inquiry and seeks to explain the biological diversity observed in the fossil record and current ecosystems through natural processes.