Insights into the palaeobiology of an early Homo infant: multidisciplinary investigation of the GAR IVE hemi-mandible, Melka Kunture, Ethiopia

• Published in: Scientific reports Vol. 11; no. 1; p. 23087
• Main Authors: Le Cabec, Adeline, Colard, Thomas, Charabidze, Damien, Chaussain, Catherine, Di Carlo, Gabriele, Gaudzinski-Windheuser, Sabine, Hublin, Jean-Jacques, Melis, Rita T., Pioli, Laura, Ramirez-Rozzi, Fernando, Mussi, Margherita
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 29.11.2021; Nature Publishing Group; Nature Portfolio
• Subjects: 631/181/19/2471; 631/181/27; Amelogenesis Imperfecta; Animals; Archaeology - methods; Archaeology and Prehistory; Babies; Biodiversity; Biological anthropology; Biological Evolution; Breastfeeding & lactation; Children; Dental enamel; Dental Enamel - anatomy & histology; Diagnosis; Disease; Enamel; Ethiopia; Evolution; Female; Food; Fossils; Genetic disorders; Geography; Head; Hominidae - growth & development; Hominids; Humanities and Social Sciences; Humans; Infants; Interdisciplinary Research; Life history; Life Sciences; Mandible; Mandible - abnormalities; Mandible - growth & development; multidisciplinary; Neuroimaging; Ontogeny; Paleontology - methods; Populations and Evolution; Science; Science (multidisciplinary); Synchrotrons; Taphonomy; Teeth; Tooth - growth & development; Weaning; Ethiopia
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/s41598-021-02462-1

Childhood is an ontogenetic stage unique to the modern human life history pattern. It enables the still dependent infants to achieve an extended rapid brain growth, slow somatic maturation, while benefitting from provisioning, transitional feeding, and protection from other group members. This tipping point in the evolution of human ontogeny likely emerged from early Homo. The GAR IVE hemi-mandible (1.8 Ma, Melka Kunture, Ethiopia) represents one of the rarely preserved early Homo infants (~ 3 years at death), recovered in a richly documented Oldowan archaeological context. Yet, based on the sole external inspection of its teeth, GAR IVE was diagnosed with a rare genetic disease–amelogenesis imperfecta (AI)–altering enamel. Since it may have impacted the child’s survival, this diagnosis deserves deeper examination. Here, we reassess and refute this diagnosis and all associated interpretations, using an unprecedented multidisciplinary approach combining an in-depth analysis of GAR IVE (synchrotron imaging) and associated fauna. Some of the traits previously considered as diagnostic of AI can be better explained by normal growth or taphonomy, which calls for caution when diagnosing pathologies on fossils. We compare GAR IVE’s dental development to other fossil hominins, and discuss the implications for the emergence of childhood in early Homo .