Early humans had a coarse diet that involved more chewing and biting; the thinking is that the forces involved stimulated growth of the jaw, creating space for the wisdom teeth to emerge.
This implies they were adapted to a more coarse diet and although they doubtless would take what they could get, they would have been able to effectively handle tough, and especially woody, food.
Ruminal starch digestion was the highest with the early fine diet (95.4% of intake) and the lowest with the late coarse diet (71.3% of intake), and 70% of starch escaping ruminal digestion was digested in the small intestine.
A comparison of subjects with known exposure to a non-acidic but coarse diet and subjects with an acidic, but refined diet using silicon impressions revealed that in the former, the scooped out dentine was significantly shallower than in the latter.
The result was that land mammals were already at an advantage, having developed complex digestive systems due to the coarse diets they were used to on land.
These teeth, which were continually ground down by chewing, allowed the animal to consume a coarse, abrasive diet of vegetation.
"Let us educate our children, even though it should us subject to a coarser or scantier diet, and disrobe us of our few fine garments," Douglass wrote in July 1848.
The molars were adapted to their diet of coarse tundra grasses, with more enamel plates and a higher crown than their earlier, southern relatives.
Many of them gradually change their traditional Chinese diets, which are rich in legumes, vegetables and coarse grains, into western diet, including the rural communities.
Worn teeth in an Egyptian mummy hinted at a diet of hard, coarse grains.
