Body size reduction in mammals is accompanied by only a moderate reduction in brain size, so that the brains of dwarfs are proportionately larger than those of giants. Here, the brains of extinct dwarf hippos from the island of Madagascar are shown to be disproportionately very much smaller than those of their closest mainland relatives. If this trend no longer holds true on islands, it may explain the exceptionally small brain size of the diminutive hominin, Homo floresiensis.
- Eleanor M. Weston
- Adrian M. Lister