There are two reasons uncalibrated dates must be mentioned: 1) this prevents people from making up any number they please, and 2) it is for the sake of posterity, where future scientists can check the results and apply new ideas of calibration. Radiocarbon dates are affected by many outside factors.
Evolutionists assume that the rate of cosmic bombardment of the atmosphere has always remained constant and that the rate of decay has remained constant.
Scientists place great faith in this dating method, and yet more than 50% of radiocarbon dates from geological and archaeological samples of northeastern North America have been deemed unacceptable after investigation.
This does not mean that recalibration is bad, indeed it is necessary, but it should make one more soberly assess any reported dates as being tentative.
The problem is that most people reporting on these issues fail to report the initial number along with the calibrated date. The Jericho controversy is soundly rooted in C-14 calibration.
Carbon is naturally in all living organisms and is replenished in the tissues by eating other organisms or by breathing air that contains carbon.