Evolution May Have Shaped Our Faces for Fighting

Mike Morgan, MD R2 Division of Emergency Medicine University of Utah School of MedicineMedicalResearch.com Interview with:
Mike Morgan, MD R2
Division of Emergency Medicine
University of Utah School of Medicine

MedicalResearch: What are the main findings of the study?

Dr. Morgan: Our paper is a review of the literature. So we do not present original data or findings. What we do is present new ideas about what drove the evolution of the hominin (bipedal ape) face.

Studies of injuries resulting from fights show that when modern humans fight the face is the primary target. The bones of the face that suffer the highest rates of fracture from fights are the bones that show the greatest increase in robusticity during the evolution of early bipedal apes, the australopiths. These are also the bones that show the greatest difference between women and men in both australopiths and modern humans.

What needs to be explained about facial differences in women and men is that in both apes and humans, males are much more violent than females and most male violence is directed at other males. Because males are the primary target of violence, one would expect more protective buttressing in males and that is what we find.  

 MedicalResearch: Were any of the findings unexpected?

Dr. Morgan: For the past 6 decades anthropologists have thought that robust faces of the first bipedal apes were the result of eating a diet that included very hard objects. The most facially robust species of australopith is often called “nut cracker man”. The biomechanics of feeding on hard objects does a very good job of explaining many of the features of the australopith face. However, recent analyses of wear patterns on their teeth suggest that most species of australopith did not eat hard objects. What we found is that the jaws and teeth are overbuilt for their diet. These overbuilt areas may have evolved to also offer buttressing and protection against facial injury during altercations.

MedicalResearch: What should interested readers take away from this study?

Dr. Morgan: We are suggesting that selection for aggressive behavior played an important role in the evolution of many aspects of our musculoskeletal system including our bipedal stance and locomotion, the proportions of our hand and the shape of our face.

MedicalResearch: What recommendations do you have for future research as a result of this study?

Dr. Morgan: For future research it would be interesting to collect more epidemiological data on trauma sustained through interpersonal violence (injuries, weapons used, gender, age, circumstances). There is ongoing research looking at strain placed on the human hand while striking and also looking at how bipedal posture affects fighting ability.


David R. Carrier, Michael H. Morgan. Protective buttressing of the hominin face. Biological Reviews, 2014; DOI: 10.1111/brv.12112




Last Updated on June 10, 2014 by Marie Benz MD FAAD