Radioactive dating relative dating
Anthropologists work with humans their cultures, societies, languages, and ways of life, in addition to their bones and artifacts.Some paleontologists do study the fossil record of humans and their relatives.
Dating schemes based on rates of radioactivity have been refined and scrutinized for several decades.Plants and animals naturally incorporate both the abundant C-12 isotope and the much rarer radiocarbon isotope into their tissues in about the same proportions as the two occur in the atmosphere during their lifetimes.When a creature dies, it ceases to consume more radiocarbon while the C-14 already in its body continues to decay back into nitrogen.However, paleontology as a whole encompasses all life, from bacteria to whales.Paleontology does not usually deal with artifacts made by humans. This is how carbon dating works: Carbon is a naturally abundant element found in the atmosphere, in the earth, in the oceans, and in every living creature.
C-12 is by far the most common isotope, while only about one in a trillion carbon atoms is C-14.
As soon as a living organism dies, it stops taking in new carbon.
The ratio of carbon-12 to carbon-14 at the moment of death is the same as every other living thing, but the carbon-14 decays and is not replaced.
The slope of the line determines the date, and the closeness of fit is a measure of the statistical reliability of the resulting date.
Technical details on how these dates are calculated are given in Radiometric dating. As with any experimental procedure in any field of science, these measurements are subject to certain "glitches" and "anomalies," as noted in the literature.
The latest high-tech equipment permits reliable results to be obtained even with microscopic samples.