While studying for your physical anthropology midterm, your classmate tells you that the bones of Lucy, a famous australopithecine specimen that dates to about 3.2 million years ago, were dated based on carbon-14 analysis. You note that this is incorrect becausea. carbon-14 analysis cannot provide accurate date estimates that far into the past.b. Lucy is a fossil hominid, meaning her bones are no longer actually bone but rather rock.c. palaeomagnetic dating is the only way to arrive at that numerical age.d. All of the above

Fossils are formed when living organisms become trapped in the earth and their soft tissues decompose but leave behind the hard tissues like bone. The bones gradually become rock due to the sediments that begin to cover the bones. Therefore, the fossil remains of Lucy are no longer bones and cannot provide the organic material that is necessary when trying to achieve carbon-14 dates from an ancient site. It is also true that C-14 dating tends not to be very accurate with a specimen as old as Lucy. There are new dating techniques being experimented with all the time in this branch of research, like the 40Ar/39Ar (Argon-Argon) dating technique, but in general, scientists have used paleomagnetic studies to try to date fossil remains as old as Lucy's.