Most scientists agree that the human species emerged somewhere in Africa about 200,000 years ago.This understanding is based on fossilized bones and skulls that have been uncovered in East Africa and dated accurately by radiometric dating.The man's body was recovered and pieces of tissue were studied for their C content by accelerator mass spectroscopy.The best estimate from this dating technique says the man lived between 33 BC. From the ratio, the time since the formation of the rock can be calculated.If we count each generation as averaging 14 years, there would be about 360,000 hand-holders in the hominine line.(Thanks to Richard Dawkins, a contemporary English biologist, for this metaphor.)Paleoarchaeologists debate what names to put on the bones they find.
Perhaps you have heard of Ice Man, a man living in the Alps who died and was entombed in glacial ice until recently when the ice moved and melted.Free 5-day trial Radiometric dating is used to estimate the age of rocks and other objects based on the fixed decay rate of radioactive isotopes.Learn about half-life and how it is used in different dating methods, such as uranium-lead dating and radiocarbon dating, in this video lesson. As we age, our hair turns gray, our skin wrinkles and our gait slows.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.