Andalusian
researchers, led by the University of Granada, have discovered a curious
characteristic of the members of the human lineage, classed as the genus Homo:
they are the only primates where, throughout their 2.5-million year history,
the size of their teeth has decreased in tandem with the increase in their
brain size. The key to this phenomenon, which scientists call
"evolutionary paradox," could be in how Homo's diet has evolved.
Digestion starts first in the mouth and, so, teeth are essential in breaking
food down into smaller pieces. Therefore, the normal scenario would be that, if
the brain grows in size, and, hence, the body's metabolic needs, so should
teeth.