Turkana Boy - Adolescence and Maturity

Adolescence and Maturity

The shape of the pelvis identifies that the specimen was a male. His estimated age at death depends upon whether the maturity stage of his teeth or skeletal is used, and whether that maturity is compared to that of modern humans or chimpanzees. A key factor here is that while modern humans have a marked adolescent growth spurt, chimpanzees do not. While initial research assumed a modern human type of growth, more recent evidence from other fossils suggests this was less present in early Homo. This affects the estimation of both his age and his likely stature as a fully grown adult.

• Anthropologists Alan Walker and Richard Leakey in 1993 estimated the boy to have been about 11–12 years old based on known rates of bone maturity.
• Christopher Dean (M. C. Dean) of University College London, in a Nova special, stated that Turkana Boy was 8 years old at death. Alan Walker and Richard Leakey, though, explain that dental dating often gives younger than actual ages.
• Ronda Graves and colleagues in the most recent review of the problems involved conclude that he would "have grown an additional five to 14 cm before reaching adulthood" and that "if, at death, he was eight to ten years of age, 154 cm tall, and growing faster than a modern human but slower than a chimpanzee. According to this scenario, KNM-WT 15000 would have attained an adult stature ranging between 159 cm and 168 cm." Moreover that "according to our preferred models of growth and development, growth in stature completed by 12 years of age (4 years after death), so that the majority of growth has already occurred.