Hominin brain size in the past 3.5 Myr. Absolute endocranial volumes of adult hominin fossils are plotted versus their geological ages. The symbols represent different hominin groups according to the legend. Adapted from Holloway et al. , Lordkipanidze et al. , Arsuaga et al. , Falk et al. , Berger et al.  and Kimbel and Rak .
(a) Longitudinal growth of head circumferences (HC) from birth to adolescence in humans (N = 228; 115 males and 113 females). (b) Comparing the proportional HC of 1-year olds with their actual HC at age 12 shows that 86% (range 82–90%) of growth is attained after the first year of life (computed for a subset of 184 individuals for which these two time points were available). Resampling the data by comparing HC at age 1 with the HC of a randomly selected child at age 12 yields the correct median, but increases the range dramatically to 73–100%. Figure based on 5000 random permutations.
Cranial and endocranial shape differences between (a) Neandertal and (b) modern human adults visualized using CT. (c) Like Neandertal babies and adults, modern human newborns (opaque surface) have elongated braincases. Until the eruption of the deciduous dentition (semitransparent surface), the modern human braincase changes its shape during a ‘globularization phase’ (GP); the corresponding virtual endocasts are shown in (d) superimposing a modern human newborn (blue surface) and a child with a 1-year old (semitransparent surface). (e) The shape changes during the GP include a relative expansion of the cerebellum and parietal bulging. Colour gradient (from blue to red) codes the vector length between surface-vertices. Figure redrawn after Gunz et al. .