Reproductive life histories: can incremental dentine isotope analysis identify pubertal growth, pregnancy and lactation?

Figures & data

Figure 1. Biplot of bulk δ¹⁵N and δ¹³C for the 10 M₃, including values during various consecutive phases of M₃ formation for individuals with indications of major dietary and/or environmental shifts.

Figure 2. Incremental dentine δ¹⁵N profiles of Seventeenth century Scottish soldiers and Nineteenth century Irish men from Kilkenny Union workhouse famine cemetery ( adapted from Beaumont and Montgomery 2016; Millard et al. 2020).

Figure 3. The exemplar of incremental dentine δ¹⁵N profiles during pubertal growth (based on linear growth patterns defined by Veldhuis et al. 2005).

Figure 4. The exemplar of maternal incremental dentine δ¹⁵N profiles during pregnancy and lactation (based on Fuller et al. 2004; D'Ortenzio et al. 2015; Fuller et al. 2006; Herrscher et al. 2017).

Table 1. Demographic and anthropometric data of the 10 individuals.

Subject	Sex	Age (years)	Ethnicity	Height (meter)	BMI	Estimated timing for M3 formation*
A	Female	23	African	1.44	22.6	1997–2012
B	Female	26	African	1.55	23.8	1994–2009
C	Female	42	African	1.54	25.8	1978–1993
D	Female	28	African	1.70	22.4	1992–2007
E	Female	25	African	1.65	24.8	1995–2010
F	Female	24	African	1.59	18.8	1996–2011
G	Female	50	African	1.72	16.3	1970–1985
H	Female	42	African	1.54	25.8	1978–1993
I	Male	43	African	1.79	29.6	1977–1992
J	Male	50	Filipino	1.76	22.0	1970–1985

*Determined using the known age range for the formation of M₃ (AlQahtani 2009) and age at tooth extraction in 2012.

Figure 5. The proposed interpretation of δ¹⁵N and δ¹³C profiles in relation to pubertal growth, for women who display life events or stress during late childhood and adolescence.

Figure 6. The proposed interpretation of δ¹⁵N and δ¹³C profiles over the time of M₃ formation, in relation to pubertal growth, for the two men.

Figure 7. The proposed interpretation of δ¹⁵N and δ¹³C profiles in relation to pubertal growth, for women with no obvious life events during late childhood and adolescence.

Table 2. Summary of isotope results for the 10 M₃.

Subject	δ^15N (‰)		δ^13C (‰)		IDIA resolution (months)	C:N
	Bulk ± SD	Range	Bulk ± SD	Range
A	10.5 ± 0.3	0.8	−17.6 ± 0.5	1.4	14	3.1
B	11 ± 0.2	0.8	−17.8 ± 0.4	1.4	10	3.2
C	10.6 ± 0.5	1.5	−18.4 ± 0.4	1.2	11	3.2
D	11 ± 0.3	0.9	−16.3 ± 0.2	0.5	11	3.2
E	11.7 ± 0.3	1.1	−17.3 ± 0.3	1.2	9	3.3
F	10.4 ± 0.4	1.6	−16.6 ± 0.5	1.6	10	3.2
G	10.4 ± 0.8	2.9	−11.8 ± 1.3	4.2	14	3.2
H	12.1 ± 0.3	1.0	−14.8 ± 0.5	1.4	18	3.2
I	12.5 ± 0.7	2.2	−11.9 ± 1.3	4.2	12	3.1
J	12 ± 0.5	1.4	−18.7 ± 0.2	0.7	10	3.3

Bulk isotope values consist of the mean of all sections for each tooth. The range of isotope values denotes the difference between the minimum and maximum isotope ratios.

Table 3. Summary of the isotope data proposed to represent pubertal growth.

Puberty	Sex	Magnitude of δ^15N reduction (‰)	Growth spurt onset	Peak weight velocity	Completion of weight gain
			(years)	(years)	(years)
PA	Female	0.8	≤9	11.9	14.7
PB	Female	0.6	10.8	12.4	14.1
PC	Female	0.9	≤9	12.6	14.4
PD	Female	0.6	<10	10–11	12.7
PE	Female	0.5	≤9.9	11.4	13
PF	Female	(1.5)	8.8	9.6	–
PG	Female	1.4	≤9.1	11.3	–
PH	Female	(0.5)	≤11.3	–	–
PI	Male	(1.5)	≤12	(18.7)	(23.5)
PJ	Male	1.3	9.8	13.1–16.5	22

Uncertain data: the proposed puberty coincides with events which also influence isotopic values.

Table 4. Summary of the isotope data interpreted as gestational events.

Pregnancy	Estimated age at conception (years)	Magnitude of δ^15N reduction (‰)	Length of anabolic state (Number of dentine-sections)	Description of post-anabolic δ^15N
GA	15.6	0.5	3	Return to pre-gestation ‘baseline’ over 3 increments
GB	14.4	0.7	3	Return to pre-gestation ‘baseline’ over 4 increments, with further increase over 2 increments
GC	15.3	0.3	1	Return to pre-gestation ‘baseline’ over 2 increments, with further increase over 4 increments
GD	14.4	0.3	1	Return to pre-gestation ‘baseline’ over 2 increments
GF	13.0	0.3	2	Return to pre-gestation ‘baseline’ over 1 increment
GG	15.1	0.8	2	Return to pre-gestation ‘baseline’ over 1 increment

Figure 8. Projected δ¹⁵N and δ¹³C shifts linked with dietary, physiological or environmental events.

Beaumont J, Montgomery J. 2016. The Great Irish Famine: identifying starvation in the tissues of victims using stable isotope analysis of bone and incremental dentine collagen. PLOS ONE. 11(8):e0160065.

 PubMed Web of Science ®Google Scholar

Millard AR, Annis RG, Caffell AC, Dodd LL, Fischer R, Gerrard CM, Graves CP, et al. 2020. Scottish soldiers from the Battle of Dunbar 1650: a prosopographical approach to a skeletal assemblage. PLOS One. 15(12):e0243369.

 PubMed Web of Science ®Google Scholar

Veldhuis JD, Roemmich JN, Richmond EJ, Rogol AD, Lovejoy JC, Sheffield-Moore M, Mauras N, Bowers CY. 2005. Endocrine control of body composition in infancy, childhood, and puberty. Endocr Rev. 26(1):114–146.

 PubMed Web of Science ®Google Scholar

Fuller BT, Fuller JL, Sage NE, Harris DA, O'Connell TC, Hedges REM. 2004. Nitrogen balance and δ15N: why you’re not what you eat during pregnancy. Rapid Commun Mass Spectrom. 18(23):2889–2896.

 PubMed Web of Science ®Google Scholar

D'Ortenzio L, Brickley M, Schwarcz H, Prowse T. 2015. You are not what you eat during physiological stress: isotopic evaluation of human hair. Am J Phys Anthropol. 157(3):374–388.

 PubMed Web of Science ®Google Scholar

Fuller BT, Fuller JL, Harris DA, Hedges REM. 2006. Detection of breastfeeding and weaning in modern human infants with carbon and nitrogen stable isotope ratios. Am J Phys Anthropol. 129(2):279–293.

 PubMed Web of Science ®Google Scholar

Herrscher E, Goude G, Metz L. 2017. Longitudinal study of stable isotope compositions of maternal milk and implications for the paleo-diet of infants. Bull Mém Soc Anthr Paris. 29:131–139.

 Google Scholar

AlQahtani SJ. 2009. An atlas of tooth development and eruption. London: Queen Mary College University of London.

 Google Scholar