The evolutionary history of modern humans is complex. This is partly due to a poor fossil record in the last few hundred thousand years and the lack consensus on the classification of a number of fossils from Africa and Europe in the period preceding the appearance of modern people. This has led to difficulties in defining key characteristics of Homo sapiens. One of the main features classically accepted to define H. sapiens is facial retraction. This architectural framework having a face positioned more or less directly under the skull, seemingly separates H. sapiens from all fossil relatives. Facial retraction directly impacted on a number of systems including respiratory physiology, cranial base flexion, masticatory changes and other important morphological modifications such as canine fossa and re-]orientation of the anterior zygomatic bones, features that also show differences with some fossil relatives.

It is unclear whether facial retraction evolved as a result of changes in other cranial components or if this was driven by function or adaptive changes. It is also unclear what features present in the face of modern humans can be traced back to early African ancestors. To settle some of these issues, we have invited a number of leading scholars in the field in a one-day symposium co-organized by Drs. Rodrigo S. Lacruz and Juan Luis Arsuaga.