Carbon-14 has a relatively short half-life of 5730 years, meaning that the amount of carbon-14 in a sample is halved over the course of 5730 years due to radioactive decay.
By about ten half-lives, or 58,000 years, the amount of carbon-14 left in the fossil is very little- about 1/1000 of the original number of carbon-14 atoms in the fossil.
The highest rate of carbon-14 production takes place at altitudes of 9 to 15 km (30,000 to 50,000 ft).Plants take in atmospheric carbon dioxide by photosynthesis, and are ingested by animals.So, every living thing is constantly exchanging carbon-14 with its environment as long as it lives. The carbon in its body will remain until it decomposes or fossilizes.The mode of this bacteria to shed-off is through feces.Humans usually become infected mostly due to the contaminated food or water.So, using carbon dating for fossils older than 60,000 years is unreliable.Carbon dating was developed by American scientist Willard Libby and his team at the University of Chicago.At high geomagnetic latitudes, the carbon-14 spreads evenly throughout the atmosphere and reacts with oxygen to form carbon dioxide.Carbon dioxide also permeates the oceans, dissolving in the water. One of the most frequent uses of radiocarbon dating is to estimate the age of organic remains from archaeological sites. Carbon dating, also known as radiocarbon dating, is a method of estimating the age of carbon-bearing materials up to 60,000 years old.