The diamonds in the diamond study locked up carbon-14 that was available when the crystals formed. Diamonds take a very, very long time to decay back into graphite and in the meantime the carbon-14 happily sits there in the crystals.
The diamond study means absolutely nothing!!!
There are many overlapping radiometric dating methods used in conjunction with carbon-14 to create time brackets within which fossils, sedimentary rocks, and igneous rocks can be placed for dating purposes. The stratigraphic evidence in the Grand Canyon and elsewhere also shatter the creationist arguments that life on earth has only been here for a relatively short period of thousands or tens of thousands of years.
I used to believe the creationist line but a thorough and honest examination of the evidence can lead to no other conclusion than the fact that all life has evoloved and that life on earth has been here for billions of years.
Cheers to all (including you creationists-and I truly mean that),
Alex