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Updated: Feb 13, 2026
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Measurement of Lifespan in Drosophila melanogaster
Published on: January 7, 2013
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Postreproductive lifespans are rare in mammals.
Samuel Ellis1, Daniel W Franks2, Stuart Nattrass2
1Centre for Research in Animal Behaviour University of Exeter Exeter UK.
Ecology and Evolution
|March 14, 2018
Summary
Post-reproductive stages, where females live significantly after reproduction, are rare in mammals. This study found such stages are limited to humans and a few toothed whale species, clarifying a long-standing evolutionary biology debate.
Area of Science:
- Evolutionary Biology
- Gerontology
- Mammalogy
Background:
- Defining and identifying post-reproductive stages in females is challenging due to senescence and demographic factors.
- The taxonomic prevalence of post-reproductive stages in mammals remains debated, despite significant interest.
Purpose of the Study:
- To statistically distinguish true post-reproductive stages from senescence-related survival in wild mammal populations.
- To determine the prevalence of post-reproductive stages across diverse mammal species.
Main Methods:
- Constructed life tables from published data on wild mammal populations.
- Applied statistical measures to quantify post-reproductive lifespans.
- Analyzed data for 52 mammal species.
Main Results:
- Post-reproductive stages were found to be rare in the studied mammal species.
- Humans and a few species of toothed whales were identified as having true post-reproductive stages.
- The study successfully differentiated true post-reproductive stages from senescence artifacts.
Conclusions:
- The findings resolve a long-standing debate on the prevalence of post-reproductive stages in mammals.
- This research provides a foundation for future studies on the evolution and adaptive significance of post-reproductive life history traits.
- The rarity of post-reproductive stages highlights its unusual nature in the mammalian class.
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