An empirical test of evolutionary theories for reproductive senescence and reproductive effort in the garter snake Thamnophis elegans.

An empirical test of evolutionary theories for reproductive senescence and reproductive effort in the garter snake Thamnophis elegans. Research Abstract Details 

Research Abstract Table of Contents

Jump to the:

An empirical test of evolutionary theories for reproductive senescence and reproductive effort in the garter snake Thamnophis elegans. Abstract Text:

Amanda M Sparkman,Stevan J Arnold,Anne M Bronikowski,

Evolutionary theory predicts that differential reproductive effort and rate of reproductive senescence will evolve under different rates of external mortality. We examine the evolutionary divergence of age-specific reproduction in two life-history ecotypes of the western terrestrial garter snake, Thamnophis elegans. We test for the signature of reproductive senescence (decreasing fecundity with age) and increasing reproductive effort with age (increasing reproductive productivity per gram female) in replicate populations of two life-history ecotypes: snakes that grow fast, mature young and have shorter lifespans, and snakes that grow slow, mature late and have long lives. The difference between life-history ecotypes is due to genetic divergence in growth rate. We find (i) reproductive success (live litter mass) increases with age in both ecotypes, but does so more rapidly in the fast-growth ecotype, (ii) reproductive failure increases with age in both ecotypes, but the proportion of reproductive failure to total reproductive output remains invariant, and (iii) reproductive effort remains constant in fast-growth individuals with age, but declines in slow-growth individuals. This illustration of increasing fecundity with age, even at the latest ages, deviates from standard expectations for reproductive senescence, as does the lack of increases in reproductive effort. We discuss our findings in light of recent theories regarding the phenomenon of increased reproduction throughout life in organisms with indeterminate growth and its potential to offset theoretical expectations for the ubiquity of senescence.

An empirical test of evolutionary theories for reproductive senescence and reproductive effort in the garter snake Thamnophis elegans. Publishing Authors By Initials

AM Sparkman,SJ Arnold,AM Bronikowski,

For similar reproductive and urinary physiology: reproduction research abstracts see: reproductive and urinary physiology: reproduction research

PUBMED ID PMID:

MEDLINE DATE:

An empirical test of evolutionary theories for reproductive senescence and reproductive effort in the garter snake Thamnophis elegans. Journal Published:

PUBLICATION TYPE: Research Support, U.S. Gov't,

Journal: Proceedings. Biological sciences / The Royal Socie

VOLUME: 274

Page Numbers: 943-50

Journal Abbreviation: Proc. Biol. Sci.

ISSN: 0962-8452

DAY: 7

MONTH: Apr

YEAR: 2007

An empirical test of evolutionary theories for reproductive senescence and reproductive effort in the garter snake Thamnophis elegans. Information

Number of References:

LANGUAGE: eng

NlmUniqueID: 101245157

An empirical test of evolutionary theories for reproductive senescence and reproductive effort in the garter snake Thamnophis elegans. Keywords Mesh Terms:

KEYWORDS: Reproduction

MESH TERMS: physiology

Chemical & Substance for Abstract: An empirical test of evolutionary theories for reproductive senescence and reproductive effort in the garter snake Thamnophis elegans. Information

Substance Name:

Registry Number:

Grant and Affiliation Information for An empirical test of evolutionary theories for reproductive senescence and reproductive effort in the garter snake Thamnophis elegans.

AFFILIATION: Department of Ecology, Evolution and Organismal Biology, Iowa State University, Ames, IA 50011, USA.

Country: England

AGENCY: United States NIGMS

GRANT: GM35492

ACRONYM: GM

MEDLINETA: Proc Biol Sci

REFSOURCE:

DATABASENAME:

ACCESSION NUMBER:

Number Hits: 0

An empirical test of evolutionary theories for reproductive senescence and reproductive effort in the garter snake Thamnophis elegans Related Publications

• An empirical test of evolutionary theories for reproductive senescence and reproductive effort in the garter snake Thamnophis elegans.
• Experimental evidence for the adaptive evolution of growth rate in the garter snake Thamnophis elegans.