Search tips
Search criteria 


Logo of procbThe Royal Society PublishingProceedings BAboutBrowse by SubjectAlertsFree Trial
Proc Biol Sci. 2004 March 7; 271(1538): 465–470.
PMCID: PMC1691624

An evolutionary model of stature, age at first birth and reproductive success in Gambian women.


We have built a model to predict optimal age at first birth for women in a natural fertility population. The only existing fully evolutionary model, based on Ache hunter-gatherers, argues that as women gain weight, their fertility (rate of giving birth) increases-thus age at first birth represents a trade-off between time allocated to weight gain and greater fertility when mature. We identify the life-history implications of female age at first birth in a Gambian population, using uniquely detailed longitudinal data collected from 1950 to date. We use height rather than weight as an indicator of growth as it is more strongly correlated with age at first birth. Stature does not greatly influence fertility in this population but has a significant effect on offspring mortality. We model age at first reproduction as a trade-off between the time spent growing and reduced infant mortality after maturation. Parameters derived from this population are fitted to show that the predicted optimal mean age of first birth, which maximizes reproductive success, is 18 years, very close to that observed. The reaction norm associated with variation in growth rate during childhood also satisfactorily predicts the variation in age at first birth.

Full Text

The Full Text of this article is available as a PDF (131K).

Selected References

These references are in PubMed. This may not be the complete list of references from this article.
  • Belsky J, Steinberg L, Draper P. Childhood experience, interpersonal development, and reproductive strategy: and evolutionary theory of socialization. Child Dev. 1991 Aug;62(4):647–670. [PubMed]
  • Billewicz WZ, McGregor IA. The demography of two West African (Gambian) villages, 1951--75. J Biosoc Sci. 1981 Apr;13(2):219–240. [PubMed]
  • Billewicz WZ, McGregor IA. A birth-to-maturity longitudinal study of heights and weights in two West African (Gambian) villages, 1951-1975. Ann Hum Biol. 1982 Jul-Aug;9(4):309–320. [PubMed]
  • dos Santos Silva Isabel, De Stavola Bianca L, Mann Vera, Kuh Diana, Hardy Rebecca, Wadsworth Michael E J. Prenatal factors, childhood growth trajectories and age at menarche. Int J Epidemiol. 2002 Apr;31(2):405–412. [PubMed]
  • Ellis Bruce J, Bates John E, Dodge Kenneth A, Fergusson David M, Horwood L John, Pettit Gregory S, Woodward Lianne. Does father absence place daughters at special risk for early sexual activity and teenage pregnancy? Child Dev. 2003 May-Jun;74(3):801–821. [PMC free article] [PubMed]
  • Georgiadis E, Mantzoros CS, Evagelopoulou C, Spentzos D. Adult height and menarcheal age of young women in Greece. Ann Hum Biol. 1997 Jan-Feb;24(1):55–59. [PubMed]
  • Gibson Mhairi A, Mace Ruth. Labor-saving technology and fertility increase in rural Africa. Curr Anthropol. 2002 Aug-Oct;43(4):631–637. [PubMed]
  • Hulanicka B, Gronkiewicz L, Koniarek J. Effect of familial distress on growth and maturation of girls: a longitudinal study. Am J Hum Biol. 2001 Nov-Dec;13(6):771–776. [PubMed]
  • Ibáez L, Ferrer A, Marcos MV, Hierro FR, de Zegher F. Early puberty: rapid progression and reduced final height in girls with low birth weight. Pediatrics. 2000 Nov;106(5):E72–E72. [PubMed]
  • Kär P, Jokela J, Helle T, Kojola I. Direct and correlative phenotypic selection on life-history traits in three pre-industrial human populations. Proc Biol Sci. 1996 Nov 22;263(1376):1475–1480. [PubMed]
  • Kaplowitz PB, Slora EJ, Wasserman RC, Pedlow SE, Herman-Giddens ME. Earlier onset of puberty in girls: relation to increased body mass index and race. Pediatrics. 2001 Aug;108(2):347–353. [PubMed]
  • Lunn PG, Prentice AM, Austin S, Whitehead RG. Influence of maternal diet on plasma-prolactin levels during lactation. Lancet. 1980 Mar 22;1(8169):623–625. [PubMed]
  • Moore SE, Cole TJ, Poskitt EM, Sonko BJ, Whitehead RG, McGregor IA, Prentice AM. Season of birth predicts mortality in rural Gambia. Nature. 1997 Jul 31;388(6641):434–434. [PubMed]
  • Mul D, Fredriks AM, van Buuren S, Oostdijk W, Verloove-Vanhorick SP, Wit JM. Pubertal development in The Netherlands 1965-1997. Pediatr Res. 2001 Oct;50(4):479–486. [PubMed]
  • Okasha M, McCarron P, McEwen J, Smith GD. Age at menarche: secular trends and association with adult anthropometric measures. Ann Hum Biol. 2001 Jan-Feb;28(1):68–78. [PubMed]
  • Qamra SR, Mehta S, Deodhar SD. A study of relation between physical growth and sexual maturity in girls--V. Indian Pediatr. 1991 Mar;28(3):265–272. [PubMed]
  • Rush D. Nutrition and maternal mortality in the developing world. Am J Clin Nutr. 2000 Jul;72(1 Suppl):212S–240S. [PubMed]
  • Zabin LS, Kiragu K. The health consequences of adolescent sexual and fertility behavior in sub-Saharan Africa. Stud Fam Plann. 1998 Jun;29(2):210–232. [PubMed]
  • Sear R, Mace R, McGregor IA. Maternal grandmothers improve nutritional status and survival of children in rural Gambia. Proc Biol Sci. 2000 Aug 22;267(1453):1641–1647. [PMC free article] [PubMed]
  • Simondon KB, Simondon F, Simon I, Diallo A, Bénéfice E, Traissac P, Maire B. Preschool stunting, age at menarche and adolescent height: a longitudinal study in rural Senegal. Eur J Clin Nutr. 1998 Jun;52(6):412–418. [PubMed]
  • Strassmann Beverly I, Gillespie Brenda. Life-history theory, fertility and reproductive success in humans. Proc Biol Sci. 2002 Mar 22;269(1491):553–562. [PMC free article] [PubMed]
  • Tracer DP. Fertility-related changes in maternal body composition among the Au of Papua New Guinea. Am J Phys Anthropol. 1991 Aug;85(4):393–405. [PubMed]

Articles from Proceedings of the Royal Society B: Biological Sciences are provided here courtesy of The Royal Society