| Popis: |
Hominins evolved in mosaic to open habitats that experienced seasonal and larger timescale fluctuations in resources. Yet they were able to thrive and to evolve large brains that require a constant supply of high-quality foods. Analyses of overall tooth morphology and enamel microstructure indicate that mid-Pliocene hominins broadened their dietary niches and incorporated increasing amounts of abrasive foods; they probably underwent a shift towards consumption of starch-rich foods, including underground storage organs (USOs). Starches are complex carbohydrates that can be converted into simple sugars, essential for brain development and maintenance. In unheated state, however, starches are abrasive and require lengthy chewing. This conceivably explains the evolution of hominins’ large, thick-enamelled and wear-resistant teeth, as well as their relatively robust cranial morphologies. Habitat differences and competitive exclusion probably account—in large part—for differences in dietary strategies among early hominins (e.g. East and South Africa) and, hence, cranio-dental morphologies. |
