Neanderthal Growth and Development: A Survey

This thesis examines growth in size and morphological change with age in Neanderthal subadults. A catalogue and extended descriptions of the most informative individuals are provided. Some of the thesis is purely descriptive, but the subject is also approached from a life-history perspective and further draws upon brain and neurocranial development as well as the essential field of dental development. Dental and skeletal attainment of Neanderthal subadults must be evaluated against chronological age, in some cases available from counts of dental microstriae. Growth studies of modern humans are referenced as a guide to growth processes, likely to apply to closely related species, and modern standards allow comparisons with Neanderthals. Information from the physiological and dental fields and neuroscience is brought to bear on the question whether Neanderthals grew to adulthood more rapidly than living Homo sapiens, and main conclusions are as follows. Brain growth affects timing of stages of ontogeny. Neanderthal endocranial volume range coincides with modern human range, which implies similar effects for both. From infancy Neanderthals exhibited skeletal apomorphies which became more pronounced with age. By modern schedules subadults were dentally advanced but postcranially were small and grew slowly. By modern standards of percentage of adult size, using Neanderthal values, subadults were not skeletally advanced for their ages. There is therefore an apparent dissociation between dental and skeletal/somatic growth rates in Neanderthals, in contrast to Homo ergaster, in which both systems are accelerated. Hypotheses regarding the dissociation are explored. Rapid growth in recent humans is found to result principally from adequate or abundant nutrition and is therefore not always a sign of “live fast die young” life history. Ethnographical research suggests that even if adulthood were attained in fewer years the acquisition of subsistence and social skills would not be constrained.