describes the shaping of the surface of Earth by ongoing processes, and which endorsed and established gradual denudation in the wider scientific community. As denudation came into the wider conscience, questions of how denudation occurs and what the result is began arising. Hutton and Playfair suggested over a period of time, a landscape would eventually be worn down to erosional planes at or near sea level, which gave the theory the name "planation". Charles Lyell proposed marine planation, oceans, and ancient shallow seas were the primary driving force behind denudation. While surprising given the centuries of observation of fluvial and pluvial erosion, this is more understandable given early geomorphology was largely developed in Britain, where the effects of coastal erosion are more evident and play a larger role in geomorphic processes. There was more evidence against marine planation than there was for it. By the 1860s, marine planation had largely fallen from favor, a move led by Andrew Ramsay, a former proponent of marine planation who recognized rain and rivers play a more important role in denudation. In North America during the mid-19th century, advancements in identifying fluvial, pluvial, and glacial erosion were made. The work being done in the Appalachians and American West that formed the basis for William Morris Davis to hypothesize peneplanation, despite the fact while peneplanation was compatible in the Appalachians, it did not work as well in the more active American West. Peneplanation was a cycle in which young landscapes are produced by uplift and denuded down to sea level, which is the base level. The process would be restarted when the old landscape was uplifted again or when the base level was lowered, producing a new, young landscape. Publication of the Davisian cycle of erosion caused many geologists to begin looking for evidence of planation around the world. Unsatisfied with Davis's cycle due to evidence from the Western United States, Grove Karl Gilbert suggested backwearing of slopes would shape landscapes into pediplains, and W.J. McGee named these landscapes pediments. This later gave the concept the name pediplanation when L.C. King applied it on a global scale. The dominance of the Davisian cycle gave rise to several theories to explain planation, such as eolation and glacial planation, although only etchplanation survived time and scrutiny because it was based on observations and measurements done in different climates around the world and it also explained irregularities in