RTB affirms that the scientific community has reconstructed the chronological history of Earth (and the universe) with remarkable precision and accuracy. Some notable elements of that chronology include Earth’s formation 4.5 billion years ago, the first confirmed appearance of life around 3.5 billion years ago, the Cambrian explosion at 540 million years ago, and the origin of humanity somewhere between 50 and 150 thousand years ago. Obviously scientists have determined some dates more accurately than others, but the consistency of different dating techniques applied to the same event gives confidence in the overall chronology. The only group of people who seem to dispute the dates in any significant fashion are Christians who argue for a 6,000- to 10,000-year-old Earth. The links below address some of these concerns.