Book contents
- Frontmatter
- Contents
- List of contributors
- Preface
- 1 Reproduction and environment
- 2 Genetic damage and male reproduction
- 3 The microenvironment in health and cancer of the mammary gland
- 4 The energetic cost of physical activity and the regulation of reproduction
- 5 Energetic cost of gestation and lactation in humans
- 6 Adaptive maternal, placental and fetal responses to nutritional extremes in the pregnant adolescent: lessons from sheep
- 7 Growth and sexual maturation in human and non-human primates: a brief review
- 8 The evolution of post-reproductive life: adaptationist scenarios
- 9 Analysing the characteristics of the menstrual cycle in field situations in humans: some methodological aspects
- 10 An insidious burden of disease: the pathological role of sexually transmitted diseases in fertility
- 11 Family planning and unsafe abortion
- 12 Global sexual and reproductive health: responding to the needs of adolescents
- 13 Understanding reproductive decisions
- Index
- References
8 - The evolution of post-reproductive life: adaptationist scenarios
Published online by Cambridge University Press: 16 May 2011
- Frontmatter
- Contents
- List of contributors
- Preface
- 1 Reproduction and environment
- 2 Genetic damage and male reproduction
- 3 The microenvironment in health and cancer of the mammary gland
- 4 The energetic cost of physical activity and the regulation of reproduction
- 5 Energetic cost of gestation and lactation in humans
- 6 Adaptive maternal, placental and fetal responses to nutritional extremes in the pregnant adolescent: lessons from sheep
- 7 Growth and sexual maturation in human and non-human primates: a brief review
- 8 The evolution of post-reproductive life: adaptationist scenarios
- 9 Analysing the characteristics of the menstrual cycle in field situations in humans: some methodological aspects
- 10 An insidious burden of disease: the pathological role of sexually transmitted diseases in fertility
- 11 Family planning and unsafe abortion
- 12 Global sexual and reproductive health: responding to the needs of adolescents
- 13 Understanding reproductive decisions
- Index
- References
Summary
Introduction
In adaptationist scenarios, traits are selected for if they are positively correlated with reproductive success (Fisher, 1930; Price, 1970). It seems counter-intuitive, then, that natural selection would select for a dampening, or complete cessation, of reproductive ability before the end of the somatic lifespan. If the production of offspring is a means by which favorable traits can be passed to future generations, then the continued production of offspring – even the costliest of offspring – would seem to be beneficial. Why was there a phylogenetic shift in female reproductive strategy away from continued egg production in fish, amphibians, and reptiles, to a finite number of eggs that slowly dwindles across the lifespan to the point, in some mammalian species, of follicular exhaustion and low levels of ovarian hormones prior to death? In other words, why is there a menopause?
This chapter reviews the evidence for two categories of adaptationist scenarios. In the first, menopause and post-reproductive life are the direct products of natural selection. In the second, menopause and post-reproductive life are the indirect by-products of natural selection for other traits. A similar differentiation between menopause as either adaptation or epiphenomenon has already been made (Peccei, 2001), but the argument presented here takes a slightly different tack by emphasizing the byproduct scenario as also adaptationist. In the byproduct scenarios presented here, mammalian patterns of early oogenesis (egg production) and lifelong atresia (ovarian follicle loss) are the reproductive strategies that underwent positive selection.
- Type
- Chapter
- Information
- Reproduction and AdaptationTopics in Human Reproductive Ecology, pp. 149 - 170Publisher: Cambridge University PressPrint publication year: 2011
References
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