The older an organism's remains are, the less beta radiation it emits because its C-14 is steadily dwindling at a predictable rate.So, if we measure the rate of beta decay in an organic sample, we can calculate how old the sample is. Question: Kieth and Anderson radiocarbon-dated the shell of a living freshwater mussel and obtained an age of over two thousand years.
When dating wood there is no such problem because wood gets its carbon straight from the air, complete with a full dose of C-14.
The creationists who quote Kieth and Anderson never tell you this, however.
However, the amount of C-14 has not been rising steadily as Cook maintains; instead, it has fluctuated up and down over the past ten thousand years. From radiocarbon dates taken from bristlecone pines.
There are two ways of dating wood from bristlecone pines: one can count rings or one can radiocarbon-date the wood.
Living organisms are constantly incorporating this C-14 into their bodies along with other carbon isotopes.