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Determination of Reproductive Competence by Confirming Pubertal Onset and Performing a Fertility Assay in Mice and Rats
Published on: October 13, 2018
Lifetime reproductive effort in humans.
Oskar Burger1, Robert Walker, Marcus J Hamilton
1Department of Biology, Stanford University, Gilbert Hall, Stanford, CA 94305-5020, USA. oburger@stanford.edu
Proceedings. Biological Sciences
|November 6, 2009
Summary
Lifetime reproductive effort (LRE) in humans converges on an optimal value, despite unique life history traits. This suggests fundamental demographic variables predictably constrain reproductive strategies across species.
Area of Science:
- Evolutionary Biology
- Life History Theory
- Human Ecology
Background:
- Lifetime reproductive effort (LRE) quantifies energy allocated to reproduction over an organism's lifespan.
- LRE is a crucial metric for comparing life histories across diverse species.
- Theoretical models predict similar LRE values given energetic constraints, irrespective of life history strategy.
Purpose of the Study:
- To calculate LRE for natural fertility human populations.
- To compare human LRE with that of other mammals.
- To explore the implications of human ecological characteristics on LRE and life-history evolution.
Main Methods:
- Calculation of LRE in natural fertility human populations.
- Comparative analysis of LRE across human and mammalian species.
- Discussion of human-specific traits (e.g., extended post-reproductive lifespan, prolonged juvenile period, cooperative breeding) in relation to LRE.
Main Results:
- Human life-history traits result in an LRE value approximating the theoretical prediction (approx. 1.4).
- Despite unique human adaptations, reproductive strategies converge on a consistent optimal LRE.
- This convergence occurs even with a subsidized energy budget and extended adult lifespan.
Conclusions:
- Fundamental demographic variables exhibit predictable trade-offs that constrain LRE.
- Human reproductive strategies align with broader evolutionary patterns, converging on a conserved LRE value.
- LRE provides a valuable framework for understanding the evolution of diverse life histories, including that of humans.
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