Selection for increased encephalization in humans necessitated extensive brain growth after birth. To estimate changes in rates of growth and corresponding shape changes during gestation and infancy, chord and arc distances were obtained from the frontal, parietal, and occipital bones of 44 human fetuses, neonates, and infants (one year old and younger). Rates of growth in chord and arc measurements were calculated and compared using linear regression of log-transformed variables, followed by ANCOVA. Curvature of bone lengths and widths were estimated by chord/arc indices. Fetal rates of cranial growth were significantly slower while the fetal frontal and occipital bones were significantly more curved than those of infants. Fetal rates of cranial growth decrease during the first six postnatal months, in conjunction with rapid changes in shape, except for parietal superior-inferior height where bossing of the bone is similar in fetuses and neonates.
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