However, rocks and other objects in nature do not give off such obvious clues about how long they have been around.
They are believed to be the most ancient common ancestor, or "stem" species, from which all later hominids sprang. Estimating the age of hominid fossils is usually a painstaking, two-part process, involving both "absolute" and "relative" dating.That causes a dating problem with any animal that eats seafood. After about ten half-lives, there's very little C14 left.So, anything more than about 50,000 years old probably can't be dated at all.Radiometric dating, or radioactive dating as it is sometimes called, is a method used to date rocks and other objects based on the known decay rate of radioactive isotopes.Different methods of radiometric dating can be used to estimate the age of a variety of natural and even man-made materials.The methods work because radioactive elements are unstable, and they are always trying to move to a more stable state. This process by which an unstable atomic nucleus loses energy by releasing radiation is called radioactive decay.