Young Earth creationism (YEC) is a form of creationism, a religious belief which holds that the universe, Earth, and all life on Earth were created by direct acts of God less than 10,000 years ago. Its primary adherents are Christians who subscribe to a literal interpretation of the creation narrative in the Bible's Book of Genesis and believe that God created the Earth in six 24-hour days. In contrast to YEC, old Earth creationism is the belief in a metaphorical interpretation of the Book of Genesis and the scientifically-determined estimated ages of the Earth and Universe.
Since the mid-20th century, young Earth creationists—starting with Henry Morris (1918–2006)—have devised and promoted a pseudoscientific explanation called "creation science" as a basis for a religious belief in a supernatural, geologically recent creation. Evidence from numerous scientific disciplines contradicts YEC, showing the age of the universe as 13.8 billion years, the formation of the Earth as at least 4.5 billion years ago, and the first appearance of life on Earth as occurring at least 3.5 billion years ago.
A 2017 Gallup creationism survey found that 38% of adults in the United States inclined to the view that "God created humans in their present form at one time within the last 10,000 years" when asked for their views on the origin and development of human beings, which Gallup noted was the lowest level in 35 years.
The first major comprehensive draft of Genesis was composed by the Yahwist in the late 7th or the 6th century BC, during the Babylonian captivity, with later additions made by the priestly source in the post-exilic period.