You analyze the ratio of radioisotope carbon 14, or ¹⁴C, in these fossil bones. ¹⁴C has a half-life of about 5,000 years. You calculate that these fossil bones have about 12.5% of their original amount of ¹⁴C left. Based on this, you calculate that the fossil bones _______ and thus the age of this human habitation site ________ are around.