Shell Necklace a Sign of 100,000-Year-Old Culture [audio 3min]

Scientists have found evidence that modern human culture dates back at least 100,000 years. The evidence is in the form of ancient shells collected at sites in Israel and Algeria. The shells were perforated, apparently for use as personal decorations. Archeologists say that suggests people were expressing themselves with symbols - something associated with modern human culture. Jon Hamilton reports.