Dynamic tracking of breastfeeding and weaning in carbon isotopes of tooth enamel
Kimura, Yuri (Institut Català de Paleontologia Miquel Crusafont)
Cerling, Thure E. (University of Utah)
Yamada, Keita (Institute of Science Tokyo)
Seki, Azusa (Fukushima Medical Device Industry Promotion Agency)
Casanovas i Vilar, Isaac (Institut Català de Paleontologia Miquel Crusafont)
Flynn, Lawrence J. (Harvard University)
Jacobs, Louis L. (Southern Methodist University)

Date:	2026
Abstract:	Stable carbon isotopes are fundamental for dietary and life-history reconstructions across living and fossil mammals. However, commonly used enamel-diet isotopic offsets are primarily derived from large herbivores and rarely account for breastfeeding in developing teeth. We present controlled feeding experiments using mother-pup pairs of four rodent species to quantify dynamic change in the carbon isotope composition of tooth enamel during early development. Breastfeeding induces a 13C depletion of up to 4 per mil in early-forming teeth. The weaning signal is propagated from the first molar (m1) through m3 with a progressive change from milk to a fully adult diet, with a "half-life" of about 20 days for the rodents. Despite lipid-rich dietary influence, the offset between enamel and progressively changing diet stabilizes at 12. 1 per mil in small mammals, consistent with enrichment values measured in later-forming teeth. This framework advances our understanding of life-history strategies and the ecology of mammals in the past.
Note:	Altres ajuts: CERCA Programme/Generalitat de Catalunya
Rights:	Aquest document està subjecte a una llicència d'ús Creative Commons. Es permet la reproducció total o parcial, la distribució, la comunicació pública de l'obra i la creació d'obres derivades, sempre que no sigui amb finalitats comercials, i sempre que es reconegui l'autoria de l'obra original.
Language:	Anglès
Document:	Article ; recerca ; Versió publicada
Published in:	iScience, Vol. 29, Num. 4 (April 2026) , art. 115350, ISSN 2589-0042

DOI: 10.1016/j.isci.2026.115350

16 p, 2.5 MB

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Research literature > UAB research groups literature > Research Centres and Groups (research output) > Experimental sciences > Institut Català de Paleontologia Miquel Crusafont (ICP)
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Articles > Published articles