The age of the Earth

Although earlier scientists didn’t have the tools to date the age of the Earth as we do today, they understood that the lower bands (and the fossils in them) were older than the higher bands and their fossils. Still, Darwin had no idea how immensely old the Earth was or how long the evolutionary process had been going on. Even when people began to understand that the world was quite a bit older than previously thought, they couldn’t give an exact age to it. Today, scientists know quite a bit more. First, through radioactive dating, a painfully complex process whose details you don’t need to worry about, they know that the Earth is about 4.5 billion years old. Scientists also know that life has existed on Earth for at least 3.5 billion years — a number that keeps changing as older and older fossils are found. Although the age of the Earth may seem to be somewhat unrelated to evolution (rock, stone, and tectonic plates aren’t living organisms and, therefore, don’t “evolve”), it’s actually very important to the theory of evolution because biological evolution needs time to happen. By knowing the actual age of the Earth and how long life has been present, scientists can ask whether enough time has passed for simple creatures such as the ones they see in the oldest rocks to evolve into more complex creatures, such as the ones that can write and edit books. The quick answer: Yes.