Radiometric dating is used to estimate the age of rocks in order to estimate the age of fossils. Radioactive atoms are everywhere, and scientists have found a way to estimate the age of rocks, specifically igneous and volcanic rocks, based on the number of the radioactive atoms within them (Berkeley, 2006). This has been important in helping our understanding of evolution, because it puts in place a timeline of found fossils which have then led to a better understanding of the evolutionary tree.
Historic Relationship to Evolution
In the late 19th century, scientists found that radioactive elements have a measurable rate of decay, and that by analyzing rocks, they were able to tell when they formed (Pojeta & Springer, 2001). Because radioactive atoms are unstable, they give off energy and change can be detected through tests (Pojeta & Springer, 2001). Scientists use this information to determine the age of fossils. Most fossils are found in sedimentary rocks, so geologists can estimate the age of the fossil by dating the igneous and volcanic rocks above and below the fossil. This is called “bracketing” (Berkeley, 2006).
The process of radiometric dating helped to validate Darwin and the theory of natural selection. One of the biggest causes for criticism came from the number of generations needed for Darwin’s theory to truly occur. After scientists were able to use radiometric dating to estimate the age of the Earth, 4.66 billion years, this theory became more widely accepted because there would have been enough time lapse for complex organisms to evolve (CAS, 2013).
Berkeley. 2006. Radiometric Dating. Retrieved from: http://evolution.berkeley.edu/evosite/evo101/IIE1aAtomicclocks.shtml.
CAS. 2013. Validating Darwin with Radiometric Dating. Retrieved from: http://www.cas.org/news/insights/science-connections/darwin
Pojeta, J. Jr., & Springer, D. A. 2001. Dating the Fossil Record. Retrieved from: http://www.agiweb.org/news/evolution/datingfossilrecord.html.