January 26, 2006

Expanding Heads and Shrinking Faces

From the BBC news story Time changes modern human's face:








The scientists took samples from a sunken ship, the Mary Rose, and from plague victims. The latter sample might be biased, since different head shapes have been shown in the past to have better chances of survival; however, the sample from the Mary Rose should be random, and the two historical samples tend to agree in their differentiation from modern populations.

From the paper:
For S-CVa, the measurement that is most representative of the anterior cranial fossa, there were significant differences between all three groups with size increasing through the ages. The anterior cranial fossa houses the frontal lobe of the brain, the great development of which is often held to be the major distinction between the human race and other primates. In particular the prefrontal areas are concerned with intellect35 and the increased intracranial dimensions and high foreheads of the modern group are evidence that brain size has increased over the centuries.
British Dental Journal (2006); 200, 33-37. doi: 10.1038/sj.bdj.4813122Help

A cephalometric comparison of skulls from the fourteenth, sixteenth and twentieth centuries

W. P. Rock, A. M. Sabieha and R. I. W. Evans

Objectives To evaluate changes in the size and shape of the skull and jaws in British populations between the thirteenth and twentieth centuries.

Method Lateral cephalometric radiograms were obtained from skulls of three groups of subjects: 30 skulls were from the remains of those who died in the London Black Death epidemic of 1348, 54 skulls were recovered from the wreck of the Mary Rose which sank in 1545 and 31 skulls were representative of modern cephalometric values.

Results Horizontal measurements in the base of the anterior cranial fossa and in the maxillary complex were greater in the modern group than in the medieval skulls. Cranial vault measurements were significantly higher (P = 0.000) in the twentieth century skulls, especially in the anterior cranial fossa.

Conclusion Results suggest that our medieval ancestors had more prominent faces and smaller cranial vaults than modern man.


1 comment:

Hugh-EMC said...

Ive read that modern human brains are actually shrinking. How would larger cranial vaults explain this? Are some ones measurements incorrect?