Potassium-Argon dating is the most efficient radioactive dating method in order to determine the absolute age of the fossils. It involves the decay of unstable Potassium-40 (K-40) into a stable Argon-40. The half-life of this Potassium-40 is approximately 1.3 billion years, so it is very much helpful to date the rocks that are of about 4.6 billion years to 100,000 years old.
Thus, the K-40 radioactive isotope would be the best to determine the exact age of the fossil that is found in the rocks that are about 600 million years old.
The fossil evidence are quite importance and provide the indirect evidence of evolution. The evolutionary history of the organisms and the common ancestory is helpful by analyzing the fossil.
The radioactive isotopes are used for the discovery and dating of the fossils. The potassium 40 is the ideal isotope to analyze the age of the fossils that are soft bodied as the potassium is almost present in almost all the organisms. The potassium has half life around 1.3 billion years and the fossil that need to be must lie between the range of about 100,000 to 1 billion years.
