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Human birthweight evolution across contrasting environments
F Thomas1, A T Teriokhin, E V Budilova
1Centre d'Etude sur le Polymorphisme des Micro-Organismes CEPM/UMR CNRS-IRD 9926 Equipe: Evolution des Systèmes Symbiotiques, IRD, Montpellier Cedex, France. fthomas@mpl.ird.fr
Journal of Evolutionary Biology
|May 20, 2004
Summary
Human birthweight variability is influenced by local evolutionary pressures. Countries with high parasitic disease prevalence show higher birthweights than predicted, supporting adaptive responses.
Area of Science:
- Evolutionary biology
- Human ecology
- Demography
Background:
- Human birthweight exhibits significant global variation.
- Understanding the drivers of this variation is crucial for evolutionary and demographic studies.
Purpose of the Study:
- To investigate the hypothesis that local selective pressures drive human birthweight variability.
- To explore the adaptive significance of birthweight in response to different fitness-reducing risks.
Main Methods:
- Development of an agent-based model to simulate evolutionary selection on life history strategy.
- Comparative analysis of birthweight data across 89 countries.
Main Results:
- Optimal birthweight is contingent on the predominant local fitness-reducing risk (somatic diseases, parasitic diseases, or environmental conditions).
- Selection favors larger children when somatic or infectious/parasitic diseases are primary risks.
- Environmental risks reduce selective pressure for high birthweight.
Conclusions:
- Global birthweight variation is significantly shaped by adaptive evolutionary responses to local conditions.
- Empirical data supports theoretical predictions, particularly the elevated birthweight in highly parasitized regions.
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