Paleontology - The Fossil Record Scientists use the age of fossils as evidence for evolution. There are two ways of dating fossils: Relative dating and absolute dating. Relative dating uses a fossil's location in rock layers to determine that fossil's approximate age. Fossils found deeper in the ground are usually the oldest. Using the chart to the right, a paleontologist can therefore know that a fossil found in layer 1 at the dig site is older than a fossil found at layer 6, for example, by relative dating.
Absolute dating determines the fossil's actual age by measuring amount of an element called carbon 4 in the fossil. There is a mathematical formula that will calculate the rate of decay of this element. By measuring the carbon-14 levels and plugging it into the math formula, the scientist can know an actual number of years old a fossil is.
1. What are the two ways of finding the age of a fossil?
2. Describe how relative dating works.
3. What does absolute dating do?
4. Why is the element carbon-14 important for paleontologists?