Scicurious has been blogging from the Experimental Biology 2011 meeting. This morning she writes about some of Lynn Copes' work: "Experimental Biology Blogging: On Thick Skulls and...Chewing." Copes has kept a crew of mice on hard foods in a cold room, to get them to chew more. Would it give them thicker skulls?
Copes found that the mice who had the soft diet had weaker jaw muscles (masseters) than those eating normal chow or chewing more in the cold, but it wasn't by much, and the skull (cranial vault) thickness did not significantly vary in any of the conditions. While this may seem like negative data, this actually suggests that, rather than the activity varying skull thickness, the thickness of our skulls may be genetically determined. Copes hopes to eventually address this question by looking at the skulls of various modern and ancient human groups. By looking at the thickness of adult skulls compared to those of children, she hopes to determine whether skull thickness is genetically determined, and if so, when, and why, our skulls got so thin.
Another point in favor of Homo erectus as stone age pachycephalosaurs.