Artist's rendering of an Australopithecus afarensis
When archaeologists hear whispers of humanity's past, it's through the painstaking work of piecing together a story from artifacts and fossilized remains: The actual calls, grunts, and other sounds made by our evolutionary ancestors didn't fossilize. But working backward from clues in ancient skeletons, Dutch researcher Bart de Boer
has built plastic models of an early hominin
's vocal tract---and, by running air through the models, recreated the sounds our ancestors may have made millions of years ago. Non-human primates have an organ called an air sac, a large cavity that connects to the vocal tract. The air sac links onto an extension on the hyoid bone
known as the hyoid bulla. Modern humans have neither an air sac nor an extension on the hyoid bone. But Australopithecus afarensis
---a hominin species that roamed Africa approximately 3.9 million to 2.9 million years ago---had a ...
